Design of Highways, Bridges and Tunnels
SHC 304 – Highway Facilities and Utilities Design - Passive
Safety Systems Design
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SAUDI HIGHWAY CODE (SHC)
SHC 304 – Highway Facilities and Utilities Design - Passive
Safety Systems Design
SHC STEERING COMMITTEE
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SHC Project Director
SAUDI HIGHWAY CODE (SHC)
SHC 304 – Highway Facilities and Utilities Design - Passive
Safety Systems Design
SHC SUPERVISORY COMMITTEE
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SHC TECHNICAL COMMITTEE (SHC 304)
TABLE OF CONTENTS
TABLE OF CONTENTS................................................................................................................................ I
List of Figures ......................................................................................................................................... VI
List of Tables .......................................................................................................................................... IX
1. Introduction ....................................................................................................................................... 1
1.1. Summary of Chapters ...................................................................................................................... 1
1.2. Scope ............................................................................................................................................... 2
1.3. Reference Standards and Codes ..................................................................................................... 2
2. VRS Framework .................................................................................................................................. 5
2.1. General ............................................................................................................................................ 5
2.2. US MASH ......................................................................................................................................... 5
2.3. EN 1317 ........................................................................................................................................... 5
2.4. VRS Acceptability Aspects ............................................................................................................... 6
3. VRS Types ........................................................................................................................................... 8
3.1. General ............................................................................................................................................ 8
3.2. Surrounding Area Arrangement ...................................................................................................... 9
3.3. Additional Structures ...................................................................................................................... 9
4. Basic Parameters ............................................................................................................................. 10
4.1. General .......................................................................................................................................... 10
4.2. Hazardous Locations ..................................................................................................................... 10
4.3. Risk Classification .......................................................................................................................... 11
4.3.1. Hazard Class 1 ......................................................................................................................................... 11
4.3.2. Hazard Class 2 ......................................................................................................................................... 11
4.3.3. Hazard Class 3 ......................................................................................................................................... 11
4.3.4. Hazard Class 4 ......................................................................................................................................... 12
4.3.5. General Remarks .................................................................................................................................... 12
4.4. Critical Distance............................................................................................................................. 12
4.5. Decisive Distance........................................................................................................................... 16
4.6. Additional Remarks ....................................................................................................................... 17
5. Performance Classes ........................................................................................................................ 18
5.1. General .......................................................................................................................................... 18
5.2. Containment Level ........................................................................................................................ 18
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5.2.1. US MASH Compliance on EN 1317 ......................................................................................................... 20
5.3. Impact Severity.............................................................................................................................. 23
5.4. Deformation .................................................................................................................................. 23
5.4.1. Dynamic Deflection ................................................................................................................................ 24
5.4.2. Working Width ....................................................................................................................................... 24
5.4.3. Vehicle Intrusion ..................................................................................................................................... 26
5.4.4. Additional Remarks ................................................................................................................................ 27
5.5. Exceptional Cases .......................................................................................................................... 28
5.6. Performance Classes Requirements per VRS Types ...................................................................... 28
6. Safety Barriers Selection Process and Criteria ................................................................................. 30
6.1. General .......................................................................................................................................... 30
6.2. Highway Edge Line Areas .............................................................................................................. 30
6.2.1. Containment Level .................................................................................................................................. 30
6.2.2. Impact Severity ....................................................................................................................................... 30
6.2.3. Working Width and Vehicle Intrusion .................................................................................................... 31
6.3. Bridge and Retaining Walls Areas ................................................................................................. 33
6.3.1. General ................................................................................................................................................... 33
6.3.2. Containment Level .................................................................................................................................. 34
6.3.3. Impact Severity ....................................................................................................................................... 34
6.3.4. Working Width and Vehicle Intrusion .................................................................................................... 35
6.3.5. Incompatibility Cases .............................................................................................................................. 36
6.4. Median and Lateral Separating Islands ......................................................................................... 36
6.4.1. General ................................................................................................................................................... 36
6.4.2. Containment Levels ................................................................................................................................ 39
6.4.3. Impact Severity ....................................................................................................................................... 40
6.4.4. Working Width and Vehicle Intrusion .................................................................................................... 40
6.5. Tunnel Areas.................................................................................................................................. 43
6.6. Selection Process Flowchart.......................................................................................................... 44
7. Implementation Lengths.................................................................................................................. 47
7.1. Highway Edge Line Areas .............................................................................................................. 47
7.2. Bridge and Retaining Walls Areas ................................................................................................. 51
8. Interruption Areas ........................................................................................................................... 56
9. Terminals ......................................................................................................................................... 58
10.Crash Cushions ................................................................................................................................. 61
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11.Transitions ....................................................................................................................................... 64
12.Portable Safety Barriers ................................................................................................................... 66
12.1.
General ................................................................................................................................ 66
12.2.
Containment Levels ............................................................................................................. 66
12.3.
Working Width .................................................................................................................... 67
12.4.
Passive Protection ............................................................................................................... 68
13.Motorcyclists Protection.................................................................................................................. 69
14.Installation Details ........................................................................................................................... 70
14.1.
General ................................................................................................................................ 70
14.2.
Level Unpaved Shoulder ...................................................................................................... 70
14.3.
Inclined Unpaved Shoulder ................................................................................................. 71
14.3.1. Steel Protective Devices Anchored ......................................................................................................... 71
14.3.2. Temporary Steel and Precast Concrete Protective Devices ................................................................... 74
14.3.3. In-Situ Concrete Protective Devices ....................................................................................................... 75
14.4.
Inadequate Unpaved Shoulder ............................................................................................ 76
14.5.
Structures with Curb Heights (≤ 0.10 m) ............................................................................. 77
14.6.
Structures with Curb Heights (> 0.10 m) ............................................................................. 78
14.7.
Tolerances............................................................................................................................ 80
15.In-Situ Concrete Barriers.................................................................................................................. 81
15.1.
Special Requirements .......................................................................................................... 81
15.2.
Construction Procedure....................................................................................................... 82
15.2.1. Materials ................................................................................................................................................. 82
15.2.2. Installation .............................................................................................................................................. 83
15.2.3. Control .................................................................................................................................................... 85
15.3.
Certification and Quality Control Requirements ................................................................. 85
16.Installation, Assembly and Internal Control .................................................................................... 86
16.1.
Internal Installation Control ................................................................................................ 86
16.2.
Inspection Control ............................................................................................................... 86
16.3.
Additional Controls .............................................................................................................. 87
16.4.
Arbitration Controls ............................................................................................................. 87
17.Technical Criteria and Quality Assurance ........................................................................................ 88
17.1.
Safety Barriers ..................................................................................................................... 89
17.2.
Terminals ............................................................................................................................. 91
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17.3.
Transitions ........................................................................................................................... 92
17.4.
Crash Cushions..................................................................................................................... 93
18.Passive Safety Poles and Posts......................................................................................................... 94
18.1.
Standards ............................................................................................................................. 94
18.1.1. US MASH ................................................................................................................................................. 94
18.1.2. EN 12767 ................................................................................................................................................ 94
18.2.
Test Conditions and Performance Classes ........................................................................... 94
18.2.1. Testing of Passive Safety Poles and Posts and Types ............................................................................. 94
18.2.2. Performance Classes............................................................................................................................... 95
18.2.3. Specification Test Conditions and Performances ................................................................................... 98
18.3.
Type Selection Criteria......................................................................................................... 98
18.3.1. NE Type Support Structures ................................................................................................................... 99
18.3.2. LE Type Support Structures .................................................................................................................... 99
18.3.3. HE Type Poles ....................................................................................................................................... 100
18.3.4. Performance Class Recommendations ................................................................................................. 100
19.Special Solutions at Highway Intersection Areas ........................................................................... 102
19.1.
General .............................................................................................................................. 102
19.2.
Impact Tests....................................................................................................................... 102
19.2.1. General ................................................................................................................................................. 102
19.2.2. Impact Test Criteria .............................................................................................................................. 103
19.2.3. Collection of Impact Test Results ......................................................................................................... 105
19.2.4. Contents of Impact Technical Report ................................................................................................... 107
19.2.5. Impact Test Evaluation Criteria ............................................................................................................ 108
19.2.6. Product Requirements Document ........................................................................................................ 108
19.2.7. Production Control ............................................................................................................................... 108
References .......................................................................................................................................... 109
Appendix A - Installation, Assembly and Internal Control ................................................................. 111
A.1. Safety Barriers ............................................................................................................................. 111
A.2. Precast Concrete Safety Barriers................................................................................................. 113
A.3. In-Situ Concrete Safety Barriers .................................................................................................. 114
A.4. Crash Cushions ............................................................................................................................ 116
A.5. Transitions ................................................................................................................................... 118
A.6. Terminals ..................................................................................................................................... 119
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A.7. Connection Hooks Control .......................................................................................................... 121
A.8. Tolerances Form of In-Situ Concrete Barrier Installation ........................................................... 123
Appendix B - Glossary of Terms .......................................................................................................... 124
Appendix C - Abbreviations, Acronyms............................................................................................... 127
Appendix D - Units .............................................................................................................................. 129
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List of Figures
Figure 4-1 Critical Distances for Highways with Vposted >100 km/h as well as Typical Freeways,
Freeways with Reduced Operational Characteristics or Divided Highways with Vposted ≤ 100
km/h (FGSV, 2009) ................................................................................................................................................ 13
Figure 4-2 Critical Distances for Highways with Vposted between 80 and 100 km/h (FGSV, 2009)
...................................................................................................................................................................................... 14
Figure 4-3 Critical Distances for Highways with Vposted between 60 and 70 km/h (FGSV, 2009)
...................................................................................................................................................................................... 14
Figure 4-4 Determination of Decisive Distance (FGSV, 2009) .............................................................. 16
Figure 5-1 VRS Layout in accordance with Working Width and Paved Edge Line (FGSV, 2009)
...................................................................................................................................................................................... 25
Figure 5-2 Dynamic Deflection (D), Working Width (W) and Vehicle Intrusion (VI) (Bast, 2020a)
...................................................................................................................................................................................... 27
Figure 5-3 Performance Classes Requirements per Various Vehicle Restraint Systems Types
(FGSV, 2009 adjusted) ......................................................................................................................................... 29
Figure 6-1 Requirements, for Selecting the Minimum Containment Level for Safety Barriers at
Highway Edge Line Areas (FGSV, 2009 adjusted) ..................................................................................... 32
Figure 6-2 Typical Widths of the Lateral Configurations on Bridges ................................................ 34
Figure 6-3 Installation of Single-Sided Safety Barriers for Obstacle Protection at the Median or
Lateral Separating Island Area (FGSV, 2009)............................................................................................... 38
Figure 6-4 Requirements, for Selecting the Minimum Containment Level for Safety Barriers at
the Median or Lateral Separating Islands Areas (FGSV, 2009 adjusted) .......................................... 39
Figure 6-5 Double-Sided Safety Barrier Installed at the Middle of the Median Island (FGSV,
2009) .......................................................................................................................................................................... 40
Figure 6-6 Double-Sided Safety Barrier Installed Offset from the Median Island (FGSV, 2009)
...................................................................................................................................................................................... 41
Figure 6-7 Single-Sided Safety Barrier with Separate Action Installed at the Highway’s Edge
Lines (FGSV, 2009)................................................................................................................................................. 41
Figure 6-8 Single-Sided Safety Barrier with Common Action Installed at the Highway’s Edge
Lines (FGSV, 2009)................................................................................................................................................. 42
Figure 6-9 Safety Barriers Formation at a Tunnel Portal Layout (FGSV, 2009) .............................. 44
Figure 6-10 Procedure for the Selection of Performance Classes for Safety Barriers (FGSV, 2009
adjusted) ................................................................................................................................................................... 46
Figure 7-1 Minimum Lengths of Safety Barriers for Two-Lane Rural Highways (Single
Carriageway) (FGSV, 2009)................................................................................................................................. 49
Figure 7-2 Minimum Lengths of Safety Barriers for Divided Highways (FGSV, 2009) ................ 49
Figure 7-3 Skewed Positioning of Safety Barriers before Obstacle for Two-Lane Rural Highways
(Single Carriageway) (FGSV, 2009).................................................................................................................. 50
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SHC 304
Figure 7-4 Skewed Positioning of Safety Barriers before Obstacle for Divided Highways (FGSV,
2009) .......................................................................................................................................................................... 50
Figure 7-5 Safety Barriers on Bridge Areas (FGSV, 2009)....................................................................... 52
Figure 7-6 Exemplary Use of Crash Cushions on Separating Traffic Islands on Bridges (FGSV,
2009) .......................................................................................................................................................................... 53
Figure 8-1 Interruption of Safety Barriers for Approaches (FGSV, 2009) ......................................... 56
Figure 8-2 Interruption of Safety Barriers with Skewed Positioning of Terminals (FGSV, 2009)
...................................................................................................................................................................................... 56
Figure 8-3 Interruption of Safety Barriers with Leading - Trailing Terminals (FGSV, 2009) ...... 56
Figure 8-4 Interruption of Safety Barriers with Skewed Positioning of Barriers and Curved Area
(FGSV, 2009) ............................................................................................................................................................ 57
Figure 8-5 Interruption of Safety Barriers without Skewed Positioning of Barriers and Curved
Area (FGSV, 2009) ................................................................................................................................................. 57
Figure 9-1 Separating Islands with Safety Barriers and Leading Terminals (FGSV, 2009) ......... 59
Figure 9-2 Lateral Separating Island with Safety Barriers and Leading Terminals on Both
Pavement Edge Line Areas (FGSV, 2009) ..................................................................................................... 60
Figure 10-1 Separating Islands with Safety Barriers and Crash Cushions (FGSV, 2009)............. 62
Figure 12-1 Installation Area of Temporary Safety Barriers (FGSV, ZTV, SA, 1997) ..................... 66
Figure 12-2 Design and Structural Width of Temporary Safety Barriers (FGSV, TL, 1997) ........ 68
Figure 14-1 Height of Protective Device (hP) during the Impact Test (FGSV, 2017) .................... 71
Figure 14-2 Height of Steel Protective Device, Anchored, Downgraded Unpaved Shoulder (a ≤
0.6 m) (FGSV, 2017) .............................................................................................................................................. 72
Figure 14-3 Height of Steel Protective Device, Anchored, Downgraded Unpaved Shoulder (a >
0.6 m) (FGSV, 2017) .............................................................................................................................................. 73
Figure 14-4 Height of Steel Protective Device, Anchored, Upgraded Unpaved Shoulder (FGSV,
2017) .......................................................................................................................................................................... 73
Figure 14-5 Height of Steel Double Sided Protective Device, Anchored, Upgraded Unpaved
Shoulder (FGSV, 2017)......................................................................................................................................... 74
Figure 14-6 Construction of Foundation Base for Vertical Temporary Steel and Precast
Concrete Protective Devices Installation (FGSV, 2017) ........................................................................... 74
Figure 14-7 Height of Temporary Steel and Precast Concrete Protective Devices Installation on
Existing Surfaces with Superelevation Rate of s ≤ 6 % (negative surface superelevation rate
shown) (FGSV, 2017) ............................................................................................................................................ 75
Figure 14-8 Height of In-Situ Concrete Protective Devices, Downgraded Unpaved Shoulder (a
≤ 0.6 m) (FGSV, 2017) .......................................................................................................................................... 75
Figure 14-9 Height of In-Situ Concrete Protective Devices, Downgraded Unpaved Shoulder (a
> 0.6 m) (FGSV, 2017) .......................................................................................................................................... 76
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Figure 14-10 Height of In-Situ Concrete Protective Devices, Upgraded Unpaved Shoulder
(FGSV, 2017) ............................................................................................................................................................ 76
Figure 14-11 Height of Protective Device, on Embankment Slope with an Inadequate Unpaved
Shoulder Width (ASTRA, 2013) ........................................................................................................................ 77
Figure 14-12 Installation of Protective Device, on Embankment with Slope 1:2 - 1:4, with
Inadequate Unpaved Shoulder Width (Traffikverket, 2015). ................................................................ 77
Figure 14-13 Height of Protective Device (hE) on Structures (FGSV, 2017)..................................... 78
Figure 14-14 Height of Protective Device (hE) on Curb Heights > 0.10 m and Lateral Distance
≤ 0.25 m (FGSV, 2017) ......................................................................................................................................... 78
Figure 14-15 Height of Protective Device (hE) on Curb Heights > 0.10 m and Lateral Distance
0.25 - 1.50 m (FGSV, 2017) ................................................................................................................................ 79
Figure 14-16 Height of Protective Device (hE) on Curb Heights >0.10 m and Lateral Distance
>1.50 m (FGSV, 2017) .......................................................................................................................................... 79
Figure 15-1 Flowchart of Requirements for the Certificate of Constancy of Performance of InSitu Concrete Barriers (BASt, 2013) ................................................................................................................ 82
Figure 15-2 Indicative Form of Contraction Expansion Joint (Pseudo-Joint) (BASt, 2013) ....... 84
Figure 15-3 Flowchart of Requirements for Maintaining the Verification Validity (BASt, 2013)
...................................................................................................................................................................................... 85
Figure 18-1 Passive Safety Structures Performance Classes (EN 12767) ......................................... 98
Figure 18-2 Non-Energy Absorbing Support Structures (Willems, 2015) ....................................... 99
Figure 18-3 Low Energy Absorbing Support Structures (Willems, 2015) ...................................... 100
Figure 18-4 High Energy Absorbing Support Structures (Willems, 2015) ..................................... 100
Figure 19-1 Overview of a Special Solutions at Highway Intersection Areas Requirement (BASt,
2020b)...................................................................................................................................................................... 103
Figure 19-2 Vehicle Trajectories during Impact Tests on a SSHIA (BASt, 2020b) ....................... 104
Figure 19-3 Recovery Area for the Descriprion of Vehicle Trajectory (BASt, 2020b) ................ 106
Figure 19-4 Locations of Cameras and Video Recording Devices during Impact Tests (BASt,
2020b)...................................................................................................................................................................... 107
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List of Tables
Table 1-1 Designations and Titles for SASO Standards Applying to SHC 304 ................................. 2
Table 1-2 Designations and Titles for Other Standards Applying to SHC 304 ................................. 3
Table 3-1 Various Types of Vehicle Restraint Systems .............................................................................. 8
Table 4-1 Critical Speed of Interchange Ramps (BASt, 2020a) ............................................................ 15
Table 4-2 Suggested Clear Zone Distances for Safe System Compliance (TRB, 2015, adjusted)
...................................................................................................................................................................................... 15
Table 5-1 Impact Tests as a Function of Vehicle Type and Mass, Impact Angle and Impact
Speed (SASO EN 1317-2) ................................................................................................................................... 19
Table 5-2 Interrelation between Impact tests and Containment Levels (SASO EN 1317-2)..... 20
Table 5-3 Interrelation of EN 1317 vs US MASH based on Energy during Impact ...................... 21
Table 5-4 TL3 Compliance on L1 (TRB, 2012) ............................................................................................. 21
Table 5-5 TL4 Compliance on L2 (TRB, 2012) ............................................................................................. 22
Table 5-6 TL5, TL6 Compliance on L3 (TRB, 2012).................................................................................... 22
Table 5-7 TL5, TL6 Compliance on L4a (TRB, 2012) ................................................................................. 22
Table 5-8 TL5, TL6 Compliance on L4b (TRB, 2012) ................................................................................. 22
Table 5-9 Impact Severity Classes (SASO EN 1317) ................................................................................. 23
Table 5-10 Working Width Classes and Values (SASO EN 1317)........................................................ 25
Table 5-11 Vehicle Intrusion Classes and Values (SASO EN 1317)..................................................... 26
Table 6-1 Required Contaiment Levels for Vehicle Parapets (FGSV, 2009) .................................... 35
Table 7-1 Required Length LB against Sliding and Driving Behind (FGSV, 2009) ......................... 49
Table 7-2 Minimum Interpolated Safety Barrier Lengths LAred to Establish a Transitional Barriers
System (Bast, 2020a) ............................................................................................................................................ 51
Table 9-1 Requirements for Leading and Trailing Terminals of Safety Barriers (FGSV, 2009) . 58
Table 10-1 Performance Classes Crash Cushions with Reference to the Posted Speed (FGSV,
2009) .......................................................................................................................................................................... 61
Table 11-1 Containment Levels of Safety Barriers Transitions (FGSV, 2009) .................................. 64
Table 12-1 Containment Level and Working Width of Temporary Safety Barriers (FGSV, ZTV,
SA 1997).................................................................................................................................................................... 67
Table 14-1 Installation Height of Steel Protective Device, Anchored for Downgraded Unpaved
Shoulder (FGSV, 2017)......................................................................................................................................... 72
Table 17-1 Technical Criteria for Safety Barriers (BASt, 2019).............................................................. 89
Table 17-2 Technical Criteria for Safety Barriers related to Road Safety (BASt, 2019) ............... 90
Table 17-3 Additional Technical Criteria for Safety Barriers regarding Structures (BASt, 2019)
...................................................................................................................................................................................... 91
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Table 17-4 Technical Criteria for Terminals (BASt, 2019) ....................................................................... 92
Table 17-5 Technical Criteria for Transitions (BASt, 2019) .................................................................... 92
Table 17-6 Technical Criteria for Crash Cushions (BASt, 2019) ........................................................... 93
Table 18-1 Energy Absorption Classification as a Function of Vehicle Impact Speed (EN 12767)
...................................................................................................................................................................................... 96
Table 18-2 Occupant Safety Levels as a Function of ASI and THIV Values (EN 12767) ............. 96
Table 18-3 Backfill Types (EN 12767) ............................................................................................................ 97
Table 18-4 Performance Class Recommendations for Passive Safety Support Structures (BS EN
12767) ...................................................................................................................................................................... 101
Table 19-1 Characteristic Values of Impact Severity for SSHIA Test 1 – Test 3 (BaST, 2020b)
.................................................................................................................................................................................... 108
Table A-1 Installation, Assembly and Internal Control Form for Safety Barriers (BASt, 2019; BASt,
2020a; FGSV, 2017; all adapted) .................................................................................................................... 111
Table A-2 Installation, Assembly and Internal Control Form for Precast Concrete Safety Barriers
(BASt, 2019; BASt, 2020a; FGSV, 2017; all adapted) ............................................................................... 113
Table A-3 Installation, Assembly and Internal Control Form for In-Situ Concrete Safety Barriers
(BASt, 2019; BASt, 2020a; FGSV, 2017; all adapted) ............................................................................... 114
Table A-4 Installation, Assembly and Internal Control Form for Crash Cushions (BASt, 2019;
BASt, 2020a; FGSV, 2017; all adapted) ........................................................................................................ 116
Table A-5 Installation, Assembly and Internal Control Form for Transitions (BASt, 2019; BASt,
2020a; FGSV, 2017; all adapted) .................................................................................................................... 118
Table A-6 Installation, Assembly and Internal Control Form for Terminals (BASt, 2019; BASt,
2020a; FGSV, 2017; all adapted) .................................................................................................................... 119
Table A-7 Installation, Assembly and Internal Control Form for Connection Hooks Control
(BASt, 2019; BASt, 2020a; FGSV, 2017; all adapted) ............................................................................... 121
Table A-8 Installation, Assembly and Internal Control Form for Tolerances of In-Situ Concrete
Barriers (BASt, 2019; BASt, 2020a; FGSV, 2017; all adapted)............................................................... 123
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SHC 304
1. Introduction
1.1. Summary of Chapters
Volume SHC 304 - Highway Facilities and Utilities Design – Passive Safety Systems
Design is divided into 19 chapters. A brief outline of these chapters is given below:
Chapter 1. Introduction - This chapter provides an overview of the chapters, the scope of the
volume, and a full list of the standards referenced within the volume.
Chapter 2. VRS Framework - This chapter describes in brief the two VRS approaches that
prevail, namely, the US MASH and the European EN 1317. Interrelations regarding basic
requirements of performance and applicability aspects with core entities of the Kingdom
(National Standardization Committee and Quality Organization and the Roads General
Authority (RGA) are also outlined.
Chapter 3. VRS Types - This chapter describes the various types of vehicle restraint systems,
their areas of implementation, the surrounding area arrangements and additional structures
that can be installed along with vehicle restraint systems.
Chapter 4. Basic Parameters - This chapter lists the criteria for installing vehicle restraint
systems in terms of hazardous locations, risk classification and critical vs decisive distances.
Chapter 5. Performance Classes - This chapter outlines performance requirements of vehicle
restraint systems per type. It also addresses compliance characteristics between US MASH and
EN 1317 roadside safety barriers.
Chapter 6. Safety Barriers Selection Process and Criteria - This chapter describes the
process for assessing requirements with regard to the installation of safety barriers in areas
such as highway edge lines, bridges and retaining walls, median and lateral separating islands
and tunnels.
Chapter 7. Implementation Lengths - This chapter describes the required lengths for areas
such as highway edge lines and bridges.
Chapter 8. Interruption Areas - This chapter describes the design of safety barriers’
interruption areas.
Chapter 9. Terminals - This chapter describes the requirements for leading and trailing
terminals of safety barriers.
Chapter 10. Crash Cushions - This chapter lists the requirements of crash cushions.
Chapter 11. Transitions - This chapter outlines the criteria for selecting the appropriate
transitions between different safety barriers performance types.
Chapter 12. Portable Safety Barriers - This chapter outlines the requirements for installing
temporary safety barriers.
Chapter 13. Motorcyclists Protection - This chapter describes the requirements for the
protection of motorcyclists, in terms of additional structures on steel restraint systems and the
installation of safety barriers with declared additional protection.
Chapter 14. Installation Details - This chapter describes safety barriers’ installation details, in
terms of installation height and horizontal/vertical tolerances under various critical conditions.
SHC 304
1
Chapter 15. In-Situ Concrete Barriers - This chapter describes construction procedures and
requirements for certification and quality control for the installation of in-situ concrete barriers.
Chapter 16. Installation, Assembly and Internal Control - This chapter describes aspects
related to installation, assembly and internal controls of VRS.
Chapter 17. Technical Criteria and Quality Assurance - This chapter describes requirements
related to qualitative characteristics of various VRS types in terms of addressing concurrently
desired road safety levels, availability, quality of material and performance, factory support,
repair and replacement capabilities.
Chapter 18. Passive Safety Poles and Posts - This chapter describes test conditions,
performance classes and type selection criteria for passive safety poles and posts.
Chapter 19. Special Solutions at Highway Intersection Areas - This chapter outlines the
technical conditions and requirements for improving the performance of safety barriers and
hence road safety on such curved sections.
1.2. Scope
This volume is to be utilized as a manual by designers, contractors and authorities involved in
the selection, installation, and maintenance of vehicle restraint systems (VRS). The criteria
related to the VRS selection process in general constitute Guidelines which are binding;
however, exceptions in specific cases are allowed if they are properly supported. On the other
hand, aspects related to the installation, maintenance, controls, technical criteria, quality
assurance of VRS as well in-situ concrete barriers are Specifications, meaning that their content
is obligatory in their implementation and use.
1.3. Reference Standards and Codes
Standards and codes for all materials and procedures shall be as specified in these General
Specifications, in the Contract documents, if any, and the following, in their latest edition:
•
•
•
•
SASO Standards and Technical Regulations.
BSI British Standards Institution.
CEN European Standards.
EN European Norm.
Table 1-1 presents the SASO standards and technical regulations related to passive safety
systems design, including designations and titles.
Table 1-2 presents other standards that have been taken into consideration in this Volume.
Table 1-1 Designations and Titles for SASO Standards Applying to SHC 304
2
SHC 304
2
SASO
Title
EN 1317-1
Road Restraint Systems, Terminology and General Criteria
for Test Methods
EN 1317-2
Road Restraint Systems - Part 2: Performance Classes,
Impact Test Acceptance Criteria and Test Methods for
Safety Barriers including Vehicle Parapets
EN 1317-3
Road Restraint Systems - Part 3: Performance Classes,
Impact Test Acceptance Criteria and Test Methods for
Crash Cushions
EN 1317-4
Road Restraint Systems - Part 4: Performance Classes,
Impact Test Acceptance Criteria and Test Methods for
Transitions and Removable Barrier Sections
EN 1317-5
Road Restraint Systems - Part 5: Product Requirements and
Evaluation of Conformity for Vehicle Restraint Systems
Table 1-2 Designations and Titles for Other Standards Applying to SHC 304
BS
EN
Title
Passive Safety of Support Structures for Road
Equipment. Requirements and Test Methods.
EN 12767
SHC 304
CEN
206
Concrete – Specification, performance,
production and conformity
1090-1
Execution of Steel Structures and Aluminium
Structures, Requirements for Conformity
Assessment of Structural Components.
1090-2
Execution of Steel Structures and Aluminium
Structures, Technical Requirements for Steel
Structures.
1090-3
Execution of Steel Structures and Aluminium
Structures, Technical Requirements for
Aluminium Structures..
1317-7
Road Restraint Systems - Part 7: Performance
Classes, Impact Test Acceptance Criteria and
Test Methods for Terminals of Safety Barriers
10346
Continuously Hot-Dip Coated Steel Flat
Products for Cold Forming - Technical
Delivery Conditions
12385-4
Steel Wire Ropes – Safety, Part 4: Stranded
Ropes for General Lifting Applications
3
BS
4
EN
CEN
Title
13670
Execution of Concrete Structures
16303
Road Restraint Systems - Validation and
Verification Process for the Use of Virtual
Testing in Crash Testing Against Vehicle
Restraint System
ISO 1461
Hot Dip Galvanized Coatings on Fabricated
Iron and Steel Articles - Specifications and
Test Methods
TS 1317-8
Motorcycle Vehicle Restraint Systems that
Reduce the Impact Severity of Motorcyclist
Collisions with Safety Barriers
TR 16949
Road Restraint System - Pedestrian Restraint
System - Pedestrian Parapets
TS 17342
Road Restraint Systems - Motorcycle Road
Restraint Systems which Reduce the Impact
Severity of Motorcyclist Collisions with Safety
Barriers
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2. VRS Framework
2.1. General
Vehicle restraint systems (VRS) constitute a critical component of highway infrastructure.
During vehicle to highway infrastructure interaction, VRS are regarded as a vital passive safety
tool and are aimed at providing a forgiving highway environment. The latter, in cases of Runoff-Road (RoR) crashes, reduces the risk of serious injuries to vehicle occupants and/or third
parties.
At international level, two VRS approaches prevail; namely, the US MASH and the European
EN 1317. The following sections provide a brief outline of both contexts.
2.2. US MASH
The AASHTO Manual for Assessing Safety Hardware (MASH) is an update of existing related
NCHRP reports developed and updated in the past 50 years. The improvements to MASH
guidelines are outlined as follows:
•
•
•
•
Changes to the test vehicles.
Changes to the number and impact conditions of the test matrices.
Changes to the evaluation criteria.
Addition of new features to the test guidelines.
The basic standpoint of the MASH approach is its intention to cover the worst or most critical
conditions.
MASH guidelines outline current status for testing and evaluating the safety performance of
highway VRS. However, they do not provide reference of when, where and how vehicle
restraint systems are to be installed.
2.3. EN 1317
EN 1317 is a European Norm developed in the late 90s by the TC 226 Working Group of the
European Committee for Standardization (CEN), an association that nowadays brings together
national standardization agencies of approximately 34 European countries. EN 1317 defines
among other the performance of vehicle restraint systems resulting from common testing
protocols together with their certification procedures (rules for their entry into the market).
Notably, the EN 1317 does not include any reference to the design, installation and
maintenance of vehicle restraint systems; therefore, the designer is free to select the
appropriate vehicle restraint system based on performance, but also on in-situ requirements.
In Europe, the implementation of EN 1317 regarding the harmonized parts on vehicle restraint
systems (e.g. TRs and TSs are excluded) is mandatory for all CEN country members following
the approval and adoption from their respective National Standardization Committees. In
Saudi Arabia, the National Standardization Committee is SASO. Therefore, these harmonized
parts for SASO EN 1317 consist of the following general requirements:
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•
•
•
•
Criteria for deciding whether the installation of a vehicle restraint system alongside the
road is required.
Identification and categorization of lateral obstacles and crash hot spots depending on
whether their existence poses a risk to third parties or only to vehicle occupants.
Criteria for selecting the minimum required performance categories in accordance with
EN 1317.
Criteria for determining the minimum required implementation length.
Based on the above requirements, the characteristics of vehicle restraint systems can be
selected according to the distinctive conditions of the road sections.
EN 1317 is divided into different parts, each relating to various aspects or another type of
product. More specifically:
•
•
•
•
•
•
•
•
EN 1317 Part 1: Terminology and general criteria for test methods.
EN 1317 Part 2: Performance classes, impact test acceptance criteria and test methods
for safety barriers and vehicle parapets.
EN 1317 Part 3: Performance classes, impact test acceptance criteria and test methods
for crash cushions.
EN 1317 Part 4: Performance classes, impact test acceptance criteria and test methods
for transitions.
EN 1317 Part 5: Product requirements and evaluation of conformity for vehicle restraint
systems.
CEN/TR 16949:2016 - Road restraint system - Pedestrian restraint system - Pedestrian
parapets (Replaces TR 1317 Part 6: Pedestrian parapets).
EN 1317 Part 7: Performance classes, impact test acceptance criteria and test methods
for terminals.
TS 17342: Motorcycle vehicle restraint systems that reduce the impact severity of
motorcyclist collisions with safety barriers (Replaces TS 1317 Part 8).
2.4. VRS Acceptability Aspects
According to the SASO EN 1317 standard, the selection and design of passive safety systems
is based on knowledge of the actual characteristics of their operation and behavior on impact.
These characteristics referred to as “performance classes” must be evidenced by the relevant
certificates.
The adequacy of a vehicle restraint system shall be demonstrated by a certificate of
performance consistency (ex-compliance) by a certification body and the file of the VRS
according to SASO EN 1317 and, where applicable, additional relevant certificates, as defined
by decisions of the Roads General Authority (RGA). The above certificates must always be
requested by the competent bodies when procuring vehicle restraint systems.
Therefore, any new VRS installed in highway projects must be certified and must have passed
the tests provided for in SASO EN 1317 or, where appropriate, must meet potential relevant
additional or other technical requirements set by the RGA, as the responsible body for the
users’ safety of the Kingdom’s highway network. The criteria in selecting the appropriate
vehicle restraint system in this case are road safety, operability, technical excellence and cost
savings.
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Certification of the performance of a road safety barrier is obtained by applying the SASO EN
1317 standard under clear and specific laboratory conditions of impact tests (system layout,
system and foundation material, type and mode of foundation, surrounding area, etc.). A
conformity mark (CE marking), or an equivalent one officially accepted by SASO, shall be
provided for road safety barriers labeled as construction products.
The present volume is structured based on the EN 1317 approach. However, basic concepts of
the US MASH guidelines are also mentioned where deemed appropriate. The aim is to justify
the installation of US MASH-compliant barriers for cases where their performance corresponds
to the respective performance of barriers selected according to EN 1317 criteria (see
Section 5.2.1).
The decision of which VRS from the above two standards, EN 1317, or US MASH, will be
implemented in the construction stage, in each case or project, shall be decided by RGA, based
on the benefit-cost analysis that has to be conducted or any other criteria that the concerned
authority will select to follow.
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3. VRS Types
3.1. General
The various types of vehicle restraint systems are shown in Table 3-1.
Vehicle restraint systems offer protection in the following areas:
•
•
Highway sections or areas during construction of new roads, reconstruction or
improvement of existing roads.
Areas or sections - locations of existing roads:
o with new obstacles;
o where existing VRS need to be replaced due to aging and/or wearing;
o with high crash frequency and/or runoff road (RoR) crashes (aiming to improve
road safety).
Table 3-1 Various Types of Vehicle Restraint Systems
Vehicle Restraint Systems
Safety Barriers
Terminals
Transitions
Removable
Barriers
Crash Cushions
In order for a road restrain product to be able to enter the market, besides a simulation testing
of the digital model, an experimental crash test is also required. Compliance with certain
predefined requirements shall also be demonstrated by the corresponding test results from
accredited laboratories.
For certain types of vehicle restraint systems, experimental crash tests shall not be required.
Vehicle restraint systems with and without such requirements will be analyzed further in the
present manual.
In general, maintenance of vehicle restraint systems shall be carried out in accordance with
the specifications or instructions for their installation, as defined by the manufacturer (produce
firm) of the systems, provided that the existing systems are certified by SASO EN 1317 or,
where appropriate, as already stated, meet potential relevant additional or other technical
requirements, which are set by RGA.
The actual conditions of installation of a road safety barrier in highway infrastructure projects
usually deviate from the laboratory conditions of the impact test according to SASO EN 1317
(e.g., installation of road safety barrier also in curved highway sections, on longitudinal and
lateral grades (superelevation), speed limits incompatible with tests, etc.). As a result, the
8
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reported performance of the road safety barrier in their respective certificates does not always
coincide with the barrier’s actual operating conditions.
Therefore, if necessary, additional theoretical calculations and appropriate mathematical
simulations may be performed to predict the behavior of the VRS in deviating conditions from
the respective SASO EN 1317 tests, if the competent highway authority for the construction,
maintenance and operation of the road deems it necessary. In every case, the installation of a
road safety barrier is intended to establish acceptable road safety levels for both highway users
and third parties.
3.2. Surrounding Area Arrangement
The operation of vehicle restraint systems shall not be hindered by the arrangement of their
surrounding area. The surrounding area of vehicle restraint systems is defined as the area
between the highway’s paved edge line and the system, to which the distance to the obstacle
is added.
The following shall apply:
•
•
•
•
The area before and under the systems shall be sufficiently stabilized and conforming
to the physical test foundation soil conditions.
The arrangement of curbs in front of vehicle restraint systems shall be avoided when
their height is greater than 75 mm above the highway’s paved edge line. The same
applies to drainage facilities.
Elevation discontinuities in front of crush cushions shall be avoided.
The operation of vehicle restraint systems shall not be hindered by vegetation,
pedestals, signing poles signs and other highway equipment. This excludes passive
equipment, which complies with EN 12767.
3.3. Additional Structures
Additional structures that can be installed along with vehicle restraint systems include railings,
anti-glare panels, etc.
These structures shall not adversely affect the operation of vehicle restraint systems. In
addition, they must not pose a risk to vehicle occupants or to third parties. If this cannot be
avoided, an audit of the overall system according to SASO EN 1317 is required.
Additional structures, such as railings, which from an operational point of view are part of the
vehicle restraint system, shall always be subjected to impact tests together with the restraint
systems as a uniform system, in accordance with SASO EN 1317.
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4. Basic Parameters
4.1. General
Vehicle restraint systems are by default obstacles to the highway’s cross section. The need for
their installation arises on the basis of reducing the consequences on vehicles occupants or
third parties during a potential impact of vehicles on artificial (or natural) obstacles, or the
entry of vehicles into hazardous areas, e.g. water areas, cliffs, etc.
Prior to the installation of vehicle restraint systems, consideration shall be given to whether it
is possible through certain measures to remove lateral obstacles or to improve the roadside
configuration in the vicinity of hazardous areas. For example, such measures could be:
•
•
•
•
Provision of adequate distance between the highway’s edge line and the area requiring
protection.
Removal of hazardous obstacles.
The utilization of crash cushions adjacent to the highway’s edge line, or deformable –
detachable equipment during vehicle impact, in accordance with EN 12767 (e.g. poles
for informational signboards).
The formation of moderate embankment cut and fill side slopes.
In exceptional and justified cases, a comparative assessment between road safety and other
project design requirements may lead to a departure from the criteria for the application of
vehicle restraint systems, as set out in the present volume.
Where local conditions do not allow the application of typical VRS, solutions based on the
principles of these Guidelines shall be sought which are expected to achieve the best possible
level of protection under the given and actual conditions.
As the selection criteria for installing VRS as described in this volume entail mainly economic
and technical criteria, the competent Contracting Authority or the Head of the Authority may
decide to install vehicle restraint systems based on additional selection criteria, if such a
decision is deemed appropriate.
4.2. Hazardous Locations
During a vehicle restraint system selection process, a critical aspect is to assess the possibility
of vehicle skidding off the highway (runoff road (RoR)). Highway sections with an increased
likelihood of vehicles skidding off the highway are regarded as areas with the following
characteristics:
•
•
•
•
Consecutive curves with an unacceptable radii sequence (see Section 5.5.3 of SHC 301
(Highway Geometric Design)).
Multiple consecutive curves with radii less than 1.5 times the respective control values
Curves with unusually high deflection angle.
High crash frequency classified as vehicle skidding.
High crash frequency in general (see Appendix E of SHC 603 (Road Safety)).
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•
In the context of such an assessment, the critical vehicle type in terms of the protection of
third parties shall be the heavy goods vehicles (HGV). In contrast, all vehicle types are
considered for the protection of vehicle occupants.
The term hazardous location refers to the existence of a compact lateral (roadside) obstacle at
the highway edge lines area (e.g. tree masts or bridge piers), as well as to highway sections
with a risk for a vehicle to skid off the highway, which in turn entails a risk either to third parties
or only to the vehicle occupants.
4.3. Risk Classification
Hazardous locations are classified into hazard classes. The criteria for such a classification
depend on whether their existence involves a risk either to third parties or only to the
respective vehicle occupants.
The highway section areas for which the installation of vehicle restraint systems is required
shall be determined based on either the frequency or likelihood of road crashes occurrence
due to vehicle skidding off the highway, or as preventive measures at the discretion of the
competent highway authority.
The risk classification in certain hazard classes for such highway section areas is outlined in the
following sections.
4.3.1.
Hazard Class 1
Hazard class 1 comprises of areas requiring protection with particular risk to third parties.
Typical examples are as follows:
•
•
•
•
4.3.2.
Chemical premises, where there is a risk of explosion.
Areas with intense stopover usage, such as terminal stations, rest areas etc.
High-speed railway positioned adjacent to the highway with train speeds V > 160 km/h.
Bearing elements of structures at risk of collapsing in case of impact (bridge piers
calculated to withstand vehicle collisions or due to their large cross-section dimensions
are excluded from this rule).
Hazard Class 2
Hazard class 2 includes areas in need of protection with risk to third parties. Typical examples
include:
•
•
•
4.3.3.
Side pedestrian paths and/or cycle routes.
Railway positioned adjacent to the highway with traffic of over 30 trains per day.
Side roads with traffic of over 500 veh/d.
Hazard Class 3
Hazard class 3 consists of obstacles with particular risk to vehicle occupants. Such examples
are the following:
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•
•
•
•
4.3.4.
Non-deformable obstacles positioned lateral to the direction of traffic.
Non-deformable individual obstacles, such as trees, lighting poles, etc.
Noise barriers.
Pedestrian parapets.
Hazard Class 4
Hazard class 4 consists of obstacles with risk to vehicle occupants. Examples are as follows:
•
•
•
•
•
•
•
4.3.5.
Deformable individual obstacles, with non-energy absorbance or detachable from
their base as defined in EN 12767.
Ditches.
Cut slopes (with rise over run) > 1:3.
Fill slopes with heights over 3 m steeper than 1:3 (rise over run).
Sewers.
Water areas with depth over 0.5 m.
Wadis.
General Remarks
Overhead signing structural supports made of concrete are not classified as structures at risk
of collapse during impact, but as non-deformable surface obstacles and thus belong to hazard
class 3.
Posts for small and medium signing plates (cylindrical steel posts with outside diameter < 76
mm and steel thickness < 2.9 mm) are classified as deformable obstacles but not to those with
energy absorption and, consequently, classified in hazard class 4.
Signing poles structures are classified as non-deformable individual obstacles and,
consequently, as risk category 3. However, energy absorbing poles (passive safety poles), easily
deformable or detachable from their base, shall not be treated as obstacles according to the
present guidelines.
4.4. Critical Distance
The need to install safety barriers is determined to a large extent by the presence of a
hazardous location or obstacle within the critical distance from the highway’s edge line. The
highway edge line refers to the traffic space's lateral boundary, which coincides with the paved
edge line. The traffic space includes the traffic lanes, the inner and outer paved shoulders, as
well as the emergency lane. The gutters are not part of the traffic space.
In light of the basic rule, according to which the protection of third parties not directly involved
in a road crash requires special attention, and that, third parties may suffer severe
consequences as a result of traffic crashes, the critical distances are distinguished as follows:
•
•
12
Distance AE, where measures to protect third parties due to particularly adverse effects
of a road crash are required (hazard class 1 and 2).
Distance A, where measures to protect the occupants of a vehicle are required due to
a vehicle fall over or impact on side obstacles (hazard class 3 and 4).
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The critical distances A and AE are a function of the posted speed (Vposted) as well as the height
difference between the highway edge line and the inner boundary of the obstacle. Both
distances are also determined in accordance with the functional classification of the highway
based on certain figures, as outlined below:
•
•
•
Highways with Vposted > 100 km/h as well as typical freeways, freeways with reduced
operational characteristics or divided highways with Vposted ≤ 100 km/h (Figure 4-1).
Highways with Vposted between 80 km/h and 100 km/h (Figure 4-2).
Highways with Vposted between 60 km/h and 70 km/h (Figure 4-3).
The above-mentioned posted speed values apply only when such speeds are implemented
over extensive areas to determine the drivers’ behavior more accurately.
The critical distances A and AE shown below shall be considered as absolute minimum
distances.
Figure 4-1 Critical Distances for Highways with Vposted >100 km/h as well as Typical Freeways, Freeways with
Reduced Operational Characteristics or Divided Highways with Vposted ≤ 100 km/h (FGSV, 2009)
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Figure 4-2 Critical Distances for Highways with Vposted between 80 and 100 km/h (FGSV, 2009)
Figure 4-3 Critical Distances for Highways with Vposted between 60 and 70 km/h (FGSV, 2009)
At highway sections, where the actual running speeds are clearly below the posted value, the
operational speed may alternatively be taken into account for determining the critical
distances.
Table 4-1 shows the critical speed values used in accordance with the critical radius of the
connecting ramp at interchange areas where no posted speed has been set.
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Table 4-1 Critical Speed of Interchange Ramps (BASt, 2020a)
Critical Ramp Radius (m)
Critical Speed (km/h)
30
50
50
60
80
70
125
80
180
90
250
100
The boundary of the hazardous location shall be considered as follows:
•
•
•
•
•
•
Solid obstacles: their inner boundary (closer to the highway).
Areas in need of protection: their inner boundary (closer to the highway).
Areas with cuts/fills or water: their intersecting position with the ground level.
Bridges/retaining walls: their structural boundary.
Railways: the boundary of their lateral clearance (usually 2.50 m from the rail axis).
Streets and cycle routes: their inner traffic space boundary (closer to the highway).
In the US s approach, there is an equivalent term for the critical distance; the so called clear
zone, which is defined as the unobstructed, traversable area provided beyond the edge of the
through traveled way for the recovery of errant vehicles. It includes shoulders, bike lanes, and
auxiliary lanes (except those auxiliary lanes that function like through lanes).
Table 4-2 presents recommended clear zone distances for various speed values assuming
perception-reaction time values of 1.2 s and 2.5 s respectively. These recommended clear zone
distances are based on the Safe System approach.
For obstacles located adjacent to highway edge line areas at distances over the clear zone
values shown in Table 4-2 the installation of safety barriers is not required.
For obstacles located adjacent to highway edge line areas at distances over the critical
distances A and AE and below the clear zone values shown in Table 4-2 the potential
installation of safety barriers should be assessed on various aspects such as high crash
frequency and/or runoff road (RoR) crashes, local conditions, etc.
Table 4-2 Suggested Clear Zone Distances for Safe System Compliance (TRB, 2015, adjusted)
Speed (km/h)
140
130
120
110
100
80
60
50
Clear Zone
58
50
45
40
33
20
10
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Speed (km/h)
140
130
120
110
100
80
60
50
75
65
60
50
42
27
16
11
(1.2 s perception - reaction
time)
Clear Zone
(2.5 s perception - reaction
time)
NOTE: 2.5 s perception – reaction time applies for motorists driving longer distances on rural roads where
drowsiness and fatigue are factors and/or more appropriately, for guidelines to consider the ‘best case’ scenario
(Moon et al., 2013)
For obstacles located at medians and lateral separating islands, see Section 6.4.1.
4.5. Decisive Distance
In order to decide whether a hazardous location lies within the zone of critical distances, the
distance between the highway edge line and the inner boundary of the hazardous location is
of vital importance. This distance, known as the decisive distance, is shown in Figure 4-4.
NOTE: In the US MASH approach, the decisive distance is measured from the edge of the through traveled way
which includes paved shoulders and non-through auxiliary lanes.
Figure 4-4 Determination of Decisive Distance (FGSV, 2009)
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4.6. Additional Remarks
The necessity for installing vehicle restraint systems shall be further examined for cases where
the decisive distance is less than or equal to the critical distance - clear zone.
The aspects outlined in the above sections related to risk classification (hazard classes) and
critical – decisive distances refer to installation requirements of safety barriers at the outer
edge line areas of highways and/or bridges - retaining walls (vehicle parapets).
With regard to the installation of safety barriers at areas with median and lateral separating
islands, certain variations apply that are further discussed in the next sections (Section 6.4).
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5. Performance Classes
5.1. General
Vehicle restraint systems shall comply with the requirements of SASO EN 1317 whether they
refer to the mandatory or the currently voluntary parts. Compliance with the requirements
must be demonstrated by the corresponding test results from accredited laboratories and
provision of the Accreditation Certificate by recognized Certification Bodies. Deviation from
this rule in conjunction with the voluntarily parts of SASO EN 1317 and acceptance of any other
proof of evidence on the performance of the system by the supplier, e.g. simulation results
etc., requires the explicit permission of the responsible highway authority.
The performance of vehicle restraint systems are determined through the SASO EN 1317
standard, based on the following parameters:
•
•
•
Containment level.
Impact severity.
Deformation.
5.2. Containment Level
Containment level indicates the containment capacity of the system. More specifically, it
reveals the most unfavorable typical impact case that a vehicle restraint system can
successfully handle. It is a function of vehicle type and mass, impact angle and impact speed
and is determined in impact tests in accordance with SASO EN 1317 (Table 5-1).
The containment levels are classified according to the growing energy during impact of the
heaviest vehicle tested. The following three containment levels are reported, namely:
•
•
•
Normal (N1, N2).
High (H1, H2, H3).
Very high (H4a, H4b).
Provided that the current passenger car fleet in KSA consists of vehicles with weights over
1,500 kg, the utilization of Normal containment level (N1, N2) should be avoided.
Moreover, the CEN working group has recently introduced the “L-class”, a new level range,
which has become a testing requirement and includes on top a third (additional) test of a
middle sized vehicle, with a speed of 110 km/h) to H-class barriers (TB32). These new systems
reflect current vehicle industry trends and thus ensure a higher level of safety for users.
Therefore, in the following sections, L-class VRS will be presented as the main recommended
option against the respective H-class. The latter, where mentioned, will be for completeness
reasons.
Each containment level is defined by specific crash tests, or their combinations, that the VRS
has to undergo according to the requirements set by SASO EN 1317.
Table 5-2 shows the interrelation between VRS containment levels and impact tests, where
both H-class and L-class systems are included.
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Table 5-1 Impact Tests as a Function of Vehicle Type and Mass, Impact Angle and Impact Speed (SASO EN 13172)
Mass (kg) Speed (km/h) Impact Angle (o)
Test
Vehicle
TB 11
Car
900
100
20
TB 21
Car
1,300
80
8
TB 22
Car
1,300
80
15
TB 32
Car
1,500
110
20
TB 41
Rigid HGV
10,000
70
8
TB 42
Rigid HGV
10,000
70
15
TB 51
Bus
13,000
70
20
TB 61
Rigid HGV
16,000
80
20
TB 71
Rigid HGV
30,000
65
20
TB 81
Articulated HGV
38,000
65
20
All the parameters defining the performance of the system are calculated from the results of
these crash tests. A restraint system, in order to succeed over a crash test, needs to fulfill a
series of requirements:
•
The safety barrier shall contain and redirect the vehicle without complete breakage of
the principal longitudinal elements of the system.
•
Elements of the safety barrier must not penetrate the passenger compartment of the
vehicle.
Deformations of, or intrusion into the passenger compartment, that can cause serious
damage are not permitted.
The center of gravity of the vehicle shall not cross the centerline of the deformed
system.
The vehicle must not slide over (including rollover of the vehicle onto its side) during
or after impact, although rolling pitching and yawing are acceptable.
For tests with Heavy Good Vehicles, no more than 5 % of the mass of the ballast shall
become detached or be split during the test, until the vehicle comes to rest.
Following impact into the safety barrier or vehicle parapet, the vehicle when bouncing
back is not permitted to cross a line parallel to the initial traffic face of the system.
•
•
•
•
•
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Table 5-2 Interrelation between Impact tests and Containment Levels (SASO EN 1317-2)
Containment Level
Temporary
Barriers
High
Very High
Test
T1
TB 21
T2
TB 22
T3
TB 41 + TB 21
H1
TB 42 + TB 11
L1
TB 42 + TB 11 + TB 32
H2
TB 51 + TB 11
L2
TB 51 + TB 11 + TB 32
H3
TB 61 + TB 11
L3
TB 61 + TB 11 + TB 32
H4a
TB 71 + TB 11
L4a
TB 71 + TB 11 + TB 32
H4b
TB 81 + TB 11
L4b
TB 81 + TB 11+ TB 32
It is up to national regulations (and not EN 1317) to define which are the containment levels
(minimum) to be used in different situations according to specific criteria (traffic type, speed
limit, presence of hazards on the roadside etc.).
5.2.1.
US MASH Compliance on EN 1317
US MASH guidelines adopt respective impact tests classified in certain test levels (TL), which
are also dependent on vehicle type and mass, impact angle and impact speed. Table 5-3 shows
the compliance of US MASH against EN 1317 in terms of the developed energy during impact.
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Table 5-3 Interrelation of EN 1317 vs US MASH based on Energy during Impact
Containment
Level
Maximal
Vehicle
Mass (kg)
Speed
(km/h)
Impact
Angle (o)
Nominal
Impact
Energy (kJ)
10,000
70
15
126.6
TL3
2,270
100
25
156.7
TL4
10,000
90
15
209.6
L2
13,000
70
20
287.5
L3
16,000
80
20
462.1
L4a
30,000
65
20
572.0
TL5
36,000
80
15
596.3
TL6
36,000
80
15
596.3
38,000
65
20
724.6
EN 1317
US MASH
L1
High
Very High
L4b
NOTE: The values refer to roadside safety barriers.
The nominal impact energy values of Table 5-3 need to be adapted to address the upper and
lower tolerances and also to adjust the differences in impact angle, vehicle mass and speed
between the two approaches. This assessment, in terms of US MASH compliance on EN 1317,
delivers the conclusions shown in Table 5-4, Table 5-5, Table 5-6, Table 5-7, and Table 5-8.
Table 5-4 TL3 Compliance on L1 (TRB, 2012)
Tested to
TL3 and L1
US MASH
EN 1317
US MASH
-
NR
EN 1317
R
-
Accepted to
NOTE: R = reasonable expectation of utilization; NR = no reasonable expectation of utilization.
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Table 5-5 TL4 Compliance on L2 (TRB, 2012)
Tested to
TL4 and L2
US MASH
EN 1317
US MASH
-
R
EN 1317
NR
-
Accepted to
NOTE: R = reasonable expectation of utilization; NR = no reasonable expectation of utilization.
Table 5-6 TL5, TL6 Compliance on L3 (TRB, 2012)
Tested to
TL5, TL6 and L3
US MASH
EN 1317
US MASH
-
NR
EN 1317
R
-
Accepted to
NOTE: R = reasonable expectation of utilization; NR = no reasonable expectation of utilization.
Table 5-7 TL5, TL6 Compliance on L4a (TRB, 2012)
Tested to
TL5, TL6 and L4a
US MASH
EN 1317
US MASH
-
CC
EN 1317
R
-
Accepted to
NOTE: R = reasonable expectation of utilization; CC = case by case.
Table 5-8 TL5, TL6 Compliance on L4b (TRB, 2012)
Tested to
TL5, TL6 and L4b
US MASH
EN 1317
US MASH
-
R
EN 1317
NR
-
Accepted to
NOTE: R = reasonable expectation of utilization; NR = no reasonable expectation of utilization.
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5.3. Impact Severity
The impact severity determines the physical stress, the severity of injuries or the fatality risk of
vehicle occupants. The performed test that determines impact severity is the TB 11 type
(900 kg passenger car with an impact angle of 20 o at 100 km/h speed). It is evident that the
more compact or rigid a system is, the greater the deceleration that acts on the occupants of
the vehicle.
Impact severity shall be measured by the following indicators:
•
•
Acceleration severity index (ASI).
Theoretical head impact velocity (THIV).
Acceleration severity index (ASI) is the main parameter for the assessment of the impact
severity. ASI is a dimensionless parameter, always greater than zero, where the severity of the
impact increases for ASI > 1.
Theoretical head impact velocity (THIV) has been developed for assessing the occupant impact
severity during vehicles’ collisions with vehicle restraint systems. The occupant’s head is
considered to be a freely moving object where, as the vehicle decelerates during impact with
the vehicle restraint system, it continues moving until it strikes a surface within the interior of
the vehicle. The degree of the velocity of the theoretical head impact is considered as a
quantitative assessment of the vehicle to vehicle restraint system impact severity.
Table 5-9 outlines the various classes of impact severity.
Table 5-9 Impact Severity Classes (SASO EN 1317)
Impact Severity Class
Maximum Permissible Values
A
ASI ≤ 1.0
THIV ≤ 33 km/h
B
1.0 < ASI ≤ 1.4
THIV ≤ 33 km/h
C
1.4 < ASI ≤ 1.9
THIV ≤ 33 km/h
Systems with class A impact severity provide greater levels of safety to the occupants of a
vehicle deviating from its course compared to those with class B and should be preferred for
safety reasons, when the remaining parameters are identical.
For the same reason, systems with impact severity class B should be preferred compared to
those with class C. A system with class C impact severity may be selected only if the required
performance parameters by systems with class A or class B are not met.
5.4. Deformation
The deformation of vehicle restraint systems during impact tests are characterized by:
•
Dynamic deflection.
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•
•
Working width.
Vehicle intrusion.
The dynamic deflection, working width and vehicle intrusion parameters shall determine the
conditions for the installation of VRS as well as the necessary lateral clearances to be provided
in front of obstacles in order for the system to perform satisfactorily.
Deformation depends on both the type of system and the impact test characteristics. In order
to reduce the influence of the testing tolerances in the classification of safety barriers’
performance, the deformation indices (dynamic deflection, working width, and vehicle
intrusion) are normalized with the actual testing values for mass, speed and angle.
5.4.1.
Dynamic Deflection
The normalized dynamic deflection (D) is a parameter that evaluates the deformation of the
system under impact and is calculated as the maximum lateral displacement of the front face
of the system from its initial condition. The dynamic deflection is measured in meters during
the impact of the heavier vehicle.
It is up to national regulations (not the EN 1317) to define the criteria that VRS designers will
follow to define the maximum dynamic deflection of the system to be used on the highway,
when designing the roadside environment.
5.4.2.
Working Width
The normalized working width (W) of a system is defined as the sum of the dynamic deflection
and the structural width of the system.
Working width is usually considered as the main parameter to calculate the lateral clearance
needed behind the barrier in order for the system to operate properly. Therefore, the selection
of an appropriate VRS depends also on its available lateral distance from the obstacle.
The smaller the space available, the more rigid the system will be. For this reason there is a
direct interdependence between the impact severity and the available space for deformation,
which in turn determines the containment level.
Therefore, VRS shall be chosen so that their working width is generally smaller or equal to the
distance between the front face of the system and the front face of the obstacle (Figure 5-1)
unless these obstacles are classified as deformable according to EN 12767.
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Figure 5-1 VRS Layout in accordance with Working Width and Paved Edge Line (FGSV, 2009)
Working width is divided into 8 classes from W1 to W8 according to the growing deformation
of the system (Table 5-10).
Table 5-10 Working Width Classes and Values (SASO EN 1317)
Normalized Working Width
Class
Value (m)
W1
W1 ≤ 0.6
W2
W2 ≤ 0.8
W3
W3 ≤ 1.0
W4
W4 ≤ 1.3
W5
W5 ≤ 1.7
W6
W6 ≤ 2.1
W7
W7 ≤ 2.5
W8
W8 ≤ 3.5
In determining the required working width, the following shall be taken into account:
•
The distance of the front face of the system from the outer edge line boundary of the
highway shall be at least equal to 0.50 m. The reduction of this minimum distance
(0.50 m) shall be permitted only in exceptional cases, such as an unavoidable obstacle
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•
•
•
5.4.3.
within the working width zone. The provision of adequate visibility may require longer
distances than the minimum value of 0.50 m.
The distance of the front side of the system from the outer edge line boundary of the
highway may be increased to 1.00 - 1.50 m depending on space and traffic conditions
(e.g., streets without special pedestrian paths or cycling routes). In such cases, the
unpaved shoulder between the highway edge line and the front face of the system
shall be sufficiently stabilized (e.g. gravel coated with grass, not paved).
In hazardous areas, such as cut-fill slopes, consideration should be given to whether
the next working width class can be chosen.
The systems with greater working width class compared to the measured distance
between the front face of the system and the front face of the obstacle may be installed,
when the test results, in accordance with SASO EN 1317, indicate that there is adequacy
in the system’s containment capacity and operation. This reference is related to the
final determination of the shoulders and pedestrian paths for bridges in order to avoid
overdesigns, and can be applied as long as it does not result in a deviation from the
objective of providing protection.
Vehicle Intrusion
The normalized vehicle intrusion (VI) of a system is defined as the maximum lateral lean
(intrusion) of the impacting vehicle from the front face of the VRS.
The impact vehicle is a HGV, which includes a notional load having the width and length of the
vehicle platform and a total height of 4.0 m above the paved surface. This addresses the ‘worstcase’ lean scenario for L1 (H1), L3 (H3), L4a (H4a) and L4b (H4b) HGVs containment levels with
different platform constructions.
The VI measurement for L2 (H2) containment level shall be considered identical to the dynamic
displacement, where the actual height of the design vehicle height (bus) shall be taken.
VRS with L1 (H1), L3 (H3), L4a (H4a) and L4b (H4b) containment levels shall have both working
width (W) and vehicle intrusion (VI) parameters marked so that designers can select effective
and safe systems.
Vehicle intrusion is divided into 9 classes, from VI1 to VI9 (Table 5-11).
Table 5-11 Vehicle Intrusion Classes and Values (SASO EN 1317)
Normalized Vehicle Intrusion
26
Class
Value (m)
VI1
VI1 ≤ 0.6
VI2
VI2 ≤ 0.8
VI3
VI3 ≤ 1.0
VI4
VI4 ≤ 1.3
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Normalized Vehicle Intrusion
5.4.4.
VI5
VI5 ≤ 1.7
VI6
VI6 ≤ 2.1
VI7
VI7 ≤ 2.5
VI8
VI8 ≤ 3.5
VI9
VI9 > 3.5
Additional Remarks
In justified and exceptional cases, it is possible, due to specific local conditions and space
limitations, that certain commitments arise, for which the requirements regarding the
necessary working width and/or vehicle intrusion as described above and/or the necessary
minimum length of the vehicle restraint system, cannot be met. In such cases, all the
alternatives based on the basic principles of the present guidelines should be investigated in
order to come to a solution, which provides the maximum level of protection for the given
circumstances.
The deformation parameters of dynamic deflection, working width and vehicle intrusion are
shown in Figure 5-2.
NOTE: The 4.0 m vehicle height refers to vehicle intrusion.
Figure 5-2 Dynamic Deflection (D), Working Width (W) and Vehicle Intrusion (VI) (Bast, 2020a)
During the VRS design, at areas of tunnel portals, bridge abutments, structures at risk of
collapse, or other large and solid obstacles close to the highway’s edge line and given that the
proposed system is of L1 (H1) containment capacity and stiffer, it is necessary to take into
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account, the additional criterion of vehicle intrusion, as specified in the present guidelines and
SASO EN 1317.
5.5. Exceptional Cases
If a vehicle restraint system, for a given hazardous location, with the required containment
level and acceptable working width (and/or vehicle intrusion, where appropriate) is not
available, then one of the following shall apply:
•
•
•
•
•
•
A vehicle restraint system with a higher containment capacity and working width shall
be selected, as outlined in the present guidelines.
A vehicle restraint system with a higher containment capacity and the next working
width class shall be selected.
A vehicle restraint system with the same containment capacity and the next working
width class shall be selected, provided that the hazardous location does not constitute
an obstacle with a risk to collapse.
An appropriate posted speed shall be introduced, which either does not require the
installation of a vehicle restraint system or requires a vehicle restraint system with a
lower containment capability. The implementation of the new posted speed requires
the necessary approval from the competent highway authority.
The vehicle restraint system is installed closer to the highway’s paved edge line. In this
case, the standard distance of 0.50 m may be reduced to a distance of 0.25 m. Such a
reduction has the disadvantage of having a smaller space to arrange work zones and
traffic arrangements in general.
Consideration shall be given for replacing the obstacle, in the case of lighting poles or
signing posts, with appropriate passive safety poles and posts in accordance with EN
12767.
5.6. Performance Classes Requirements per VRS Types
Vehicle restraint systems shall comply with the respective requirements of SASO EN 1317.
Compliance with the requirements set shall be demonstrated by the corresponding test results
from accredited laboratories.
Figure 5-3 shows the performance classes requirements per various vehicle restraint systems
types.
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Vehicle Restraint Systems
Safety Barriers
&
Removable Barrier
Sections
Containment Level
Working Width Class
Vehicle Intrusion Class
Impact Severity Class
Transitions
Crash Cushions
Vehicle Exit Box
Containment Level
Permanent Lateral Displacement
Class
Permanent Lateral Displacement
Class
Impact Severity Class
Terminals
Performance Class / Speed Class
Performance Class
Impact Severity Class
Working Width Class
Vehicle Redirection Class
Impact Severity Class
Figure 5-3 Performance Classes Requirements per Various Vehicle Restraint Systems Types (FGSV, 2009 adjusted)
Additional details on the above vehicle restraint systems types are provided in the following
sections.
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6. Safety Barriers Selection Process and Criteria
6.1. General
The performance of safety barriers shall be determined in accordance with of SASO EN 1317
based on the following criteria:
•
•
•
•
Containment level.
Working width.
Vehicle Intrusion.
Impact severity.
Basic information regarding the above parameters has been already provided in previous
sections of this volume.
The requirements for safety barriers depend on their location, which may be one of the
following:
•
•
•
•
Highway edge line areas (highway’s external paved boundary).
Bridge and retaining walls areas.
Median and lateral separating islands.
Retaining walls and tunnel portals.
The requirements for portable safety barriers are analyzed in Chapter 12.
6.2. Highway Edge Line Areas
6.2.1.
Containment Level
The flowchart of Figure 6-1 shows the process for assessing economic and technical
requirements with regard to the installation of safety barriers at the highway edge line area.
Figure 6-1 also indicates the minimum required containment level in accordance with:
•
•
•
•
6.2.2.
The risk classification in terms of whether the hazard is located at a certain area or
consists of obstacle(s), and whether it constitutes a danger to third parties or to vehicle
occupants. Hazardous areas or obstacles with protection requirements not classified in
the respective hazard classes of Figure 6-1 shall be classified accordingly by the
designer.
The posted speed (Vposted).
The frequency and/or likelihood of vehicle skidding (RoR).
Traffic data, such as average daily traffic (ADT) and HGV traffic.
Impact Severity
As already mentioned, impact severity determines the physical stress, the severity of injuries
or the fatality risk of vehicle occupants.
Impact severity is quantified by assessing two components: acceleration severity index (ASI)
and theoretical head impact velocity (THIV) indices. More detailed information can be found
in Section 5.3.
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6.2.3.
Working Width and Vehicle Intrusion
Working width and vehicle intrusion are regarded as essential parameters regarding the
deformation assessment of vehicle restraint systems installation.
As far as safety barriers positioned at highway edge line areas are concerned, Section 5.4.2
and Section 5.4.3 provide a thorough insight for working width and vehicle intrusion
parameters, respectively.
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Figure 6-1 Requirements, for Selecting the Minimum Containment Level for Safety Barriers at Highway Edge Line
Areas (FGSV, 2009 adjusted)
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6.3. Bridge and Retaining Walls Areas
6.3.1.
General
Safety barriers at bridge and/or retaining walls areas are known as vehicle parapets. Vehicle
parapets are installed on the side areas of bridges or retaining walls or similar structures where
there is a risk for vertical drop.
The minimum requirements for a safety barrier to be treated as a vehicle parapet are as follows:
•
•
•
Length of bridge > 10 m.
Vertical drop > 2 m.
Length of retaining wall > 25 m.
If the above criteria are not met, the general requirements for highway edge line areas apply,
as stated in Section 6.2.
Vehicle parapets may include additional protection and restraint for pedestrians and other
highway users (combined vehicle/pedestrian parapet).
Vehicle parapets shall be selected in accordance with the risk classification where certain
criteria apply depending on whether a potential risk involves either third parties or only the
vehicle occupants.
The load classification of vehicle parapets on bridges based on the applicable guidelines shall
be determined by taking into account the measured loads during the SASO EN 1317 impact
test, transferred to the structure through both the vehicle parapet and the vehicle. In general,
for vehicle parapets with a containment level up to L1 (H1), the load determination can be
reliably performed by theoretical calculations. Such a theoretical approach is acceptable.
Selection and installation of the appropriate vehicle parapets takes as granted that the forces
applied to the barrier, and measured through the corresponding standard impact test, can be
safely received both locally by the structure’s direct support components, and entirely by the
body of the structure.
Maximum permitted values of the above may constitute additional criteria for the selection
and acceptance of vehicle parapet types beyond the required performance parameters.
In order to avoid subsequent reinforcement interventions during the design of new structures,
it is recommended to prescribe the use of a horizontal impact force classification equivalent
to 400 kN, which according to international studies covers the requirements of a large number
of L2 (H2) and L3 (H3) vehicle parapets. In this case, the use of vehicle parapets whose
horizontal force transfer to the structure is less than 400 kN categories is allowed without
special control assessments. Use of parapets with horizontal force transfer greater than 400
kN requires a structural evaluation of the structure. Their use will be only allowed if the
structure as designed and constructed proves to withstand the corresponding load with
adequate loading thresholds. This structural evaluation will be performed by the contractor
and the resulting report will be submitted to the competent highway authority for review and
approval.
Aspects related to loading capacity of bridges and respective structures that affect the
selection process of vehicle parapets are addressed in Section 3.6.5 of SHC 310 (Bridges and
Tunnels Design).
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At bridge joint areas, the vehicle parapets shall be installed in such a way that there is evidence
of no significant loss of performance due to the movements of the structure.
The typical lateral width configurations on bridges (side formations between highway’s edge
line and external edge line of structure) are 2.05 m (Figure 6-2). The lateral clearance between
the rear face of a vehicle parapet and the railing acts as an emergency and maintenance
corridor and should not be less than 0.75 m, while on existing bridges, this distance may be
reduced to 0.50 m.
Figure 6-2 Typical Widths of the Lateral Configurations on Bridges
6.3.2.
Containment Level
The containment levels of vehicle parapets for various risk classification levels are shown in
Table 6-1.
Bridges and retaining walls with Vposted ≤ 50 km/h classified as hazard class 1 normally require
a vehicle parapet with L1 (H1) containment level. For lower hazard classes (2 - 4), where Vposted
≤ 50 km/h still applies, the combination of unmountable curb with sidewalk (e.g. 20 cm high)
along with a railing reinforced with a steel-cable is selected. For cases where a sidewalk is
missing a parapet of L1 containment level is selected.
6.3.3.
Impact Severity
Regarding impact severity, it is desirable to select class A vehicle parapets where available. A
vehicle parapet with class C impact severity may be selected only if the required performance
parameters by systems with class A or class B are not met.
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Table 6-1 Required Contaiment Levels for Vehicle Parapets (FGSV, 2009)
Hazardous location
below bridge or
retaining wall
Highways
with Vposted >
100 km/h or
typical
freeways,
freeways with
reduced
operational
characteristics
or divided
highways with
Vposted ≤ 100
km/h
Highways with
Vposted ≤ 100 km/h
and
ADT(HGV) > 500
veh/d
Highways with
Vposted ≤ 100 km/h
and ADT(HGV) ≤
500 veh/d
Vposted ≤ 50
km/h
L4b
L2
L2
L1
Hazard class 1
Areas with particular
risk to third parties
Hazard class 2-4
Areas with:
• Risk to third
parties
• Particular risk for
vehicle occupants
• Risk for vehicle
occupants
Case 1
L2
L2
L1
Or
Case 2
NOTE: The curb height where the vehicle parapet is installed is up to 0.07 m for Vposted > 50 km/h. Case 1: With
sidewalk (e.g. 20 cm high) - unmountable curb (combined with railing). Case 2: Without sidewalk - parapet with
L1 containment level.
6.3.4.
Working Width and Vehicle Intrusion
For the determination of the maximum working width class, the bridge or retaining wall outer
edge line (structure edge line) shall be considered as the front face of the lateral obstacle,
provided that no sound barrier or other obstacle is installed.
The installation vehicle parapets under a higher working width class is permitted, if respective
tests according to SASO EN 1317 reveal that their containment capacity is adequate for
protecting vehicle occupants or third parties.
Vehicle intrusion shall also be taken into consideration. Vehicle intrusion is critical for cases
with high obstacles (e.g., cable bridges, gantries, etc.).
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6.3.5.
Incompatibility Cases
If the dimensional requirements regarding the typical lateral width configurations on bridges
(Figure 6-2) cannot be met, or there is no certified vehicle parapet for installation, the situation
should be assessed under the existing local conditions in terms of selecting the appropriate
deviations from the present guidelines.
Such potential deviations must be explicitly mentioned in the VRS design process and in the
relevant contract notice for the supply of the vehicle parapet.
In particular, for cases where suitable vehicle parapets with the required containment capacity
or working width cannot be found, the following process may apply:
•
•
•
•
•
Determination of containment level (see Figure 6-1).
Determination of the working width class (W) and vehicle intrusion class (VI).
o Selection of a certified vehicle parapet that meets local conditions, such as:
▪ vehicle parapet for the structure’s outer edge lines;
▪ combined vehicle/pedestrian parapet.
Reconsideration of the working width class (W) and vehicle intrusion class (VI).
o Potential replacement of working width class with the respective value of the
dynamic deflection class.
Assess potential implementation, in terms of deviating, for the following:
o Containment capacity.
o Actual vs calculated loading.
o Impact assessment of other factors.
Implementation of special solutions.
Regarding existing structures, during the process of new installation, renewal or replacement
of vehicle parapets, a proficiency assessment against a horizontal impact force classification
equivalent to 400 kN shall be preceded. If necessary, appropriate reinforcement interventions
shall take place.
Deviations from this requirement with proficiency assessment for a lower horizontal impact
force classification shall be allowed only following the approval of the competent highway
authority for cases whereby:
•
•
A vehicle parapet has already been selected that corresponds to a lower impact force
than the 400 kN force for which a bridge can withstand.
The necessary interventions are difficult, costly or even may lead to a need to extend
the interventions to other parts of the structure, in addition to the directly affected
section.
In these cases alternative measures should be implemented for the safety of the road users
(e.g. speed reduction, calming measures etc.).
6.4. Median and Lateral Separating Islands
6.4.1.
General
Safety barriers may be installed at areas of divided highways with median and lateral
separating islands where the posted speed exceeds 50 km/h.
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Regarding the installation of median barriers, another determinant parameter is the median
width. Median barriers are recommended for cases of divided highways whereby the median
width is up to 9.0 m and the average daily traffic (ADT) greater than 20,000 veh/d. For divided
highways with median widths < 15.0 m and ADT < 20,000 veh/d, the installation of median
barriers shall be decided by the competent highway authority, taking into consideration future
increment of ADT as well as crashes due to median crossings. For cases of divided highways
whereby the median width ranges from 9.0 to 15.0 m and ADT > 20,000 veh/d, the necessity
for median barrier shall be determined via a benefit-cost analysis, based on parameters such
as traffic volume, vehicle composition, median crashes history as well as other highway
geometry and topography parameters.
The criteria for providing a median barrier, if there are hazards within the median, shall be in
accordance with the critical distance and clear zone graphs and tables (Section 4.4).
For median widths over the clear zone values shown in Table 4-2 the installation of median
barriers is not required.
For obstacles located at distances over the critical distances as in Section 4.4, and below the
Safe System clear zone values shown in Table 4-2 the potential installation of safety barriers
should be assessed on various aspects such as high crash frequency and/or runoff road (RoR)
crashes, local conditions, etc.
The safety barriers installed at the median area of divided highways are designed to protect
third parties moving in the opposite direction of traffic; their containment level shall not be
less than L2 (H2).
The following options are available for placing safety barriers at median and separating islands:
•
•
•
•
Installation of double-sided safety barriers at the middle of the median island.
Installation of double-sided safety barriers at an offset from the median island.
Installation of single-sided safety barriers adjacent to the island’s edge line area with
separate (autonomous) action.
Installation of single-sided safety barriers adjacent the island’s edge line area with
common action.
In general, frequent changes regarding the safety barrier types in the island areas should be
avoided. Uniform safety barrier types without transitions are preferred. The selection criteria
of a safety barrier type along an island are based on road safety.
The double-sided systems are generally positioned in the middle of the island. For cases where
an obstacle is present (such as electromechanical equipment or sewer lines), or where the
required visibility is violated, the double-sided safety barriers may be offset laterally.
For cases where a hazardous obstacle is positioned at the median or lateral separating island,
single-sided safety barriers with separate action shall be installed (Figure 6-3).
Double-sided safety barriers may be connected by single-sided safety barriers prior to an
obstacle with a skewed rate of ≤ 1:20 (rise over run).
Frequent changes from double-sided to single-sided safety barriers positioned at the median
and adjacent to the islands edge line areas respectively should be avoided. At barrier
interruption areas or openings of the median separating island, the safety barrier shall be
positioned with the same performance class as on the adjacent parts of the island.
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NOTE: LA refers to the minimum length referenced in the testing report (according to SASO EN 1317) in order the
safety barrier to be effective.
Figure 6-3 Installation of Single-Sided Safety Barriers for Obstacle Protection at the Median or Lateral Separating
Island Area (FGSV, 2009)
Double-sided safety barriers are symmetrical systems, which are accessible from both sides of
the island, as opposed to single-sided systems. The containment level of single-sided systems
with common action can only be achieved by the cooperation of both systems, which must be
ensured during highway construction.
Where the island is sufficiently wide and the transverse slope of the median or lateral
separating island is ≤ 1:10 (rise over run), only single-sided systems shall be installed along
the boundaries of the island with separate action. The second system in this case shall be
operated as a subsidiary system when impacted by heavier vehicles in order to avoid the
vehicle entering the opposite direction of traffic (backup system).
At island areas with multiple obstacles or large transverse slopes, identical as possible systems
with the required containment capacity shall be selected (e.g. L2 (H2)), and applied uniformly
across the island (e.g. a single safety barrier with the required small working width and vehicle
intrusion); otherwise certified systems are selected that are compatible with the manufacturing
peculiarities of the island.
Additional implementation criteria for safety barriers installments along median and
separating islands are as follows:
•
•
•
•
•
•
•
•
•
•
•
Sewerage capacity.
Location of drains.
Ability of installment before obstacles.
Ability of installment at barrier interruption areas.
Ability of installment at bridge areas.
Acceptable transitions according to SASO EN 1317 in existing systems.
Visibility aspects.
Ease of repair and replacement.
Frequency of cleaning (especially in closed systems).
Ease of maintenance.
Ability of sand removal (or snow at mountainous areas with extreme weather
conditions).
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In highway design projects, a timely investigation shall be performed regarding the
compatibility between drainage aspects and VRS installation restrictions.
If safety barriers with the required containment level and sufficient working width and vehicle
intrusion width are not available, the exceptional cases in Section 5.5 shall be applied.
6.4.2.
Containment Levels
The width of a median or lateral separating island is defined as the distance between the
boundaries of the traffic area of the two highway surfaces.
The flow chart in Figure 6-4 illustrates the economic and technical criteria for selecting the
minimum required containment level of safety barriers at the median or lateral separating
islands areas in relation to:
•
•
Risk classification.
Factors affecting traffic, such as:
o Posted speed (Vposted).
o Frequency and/or likelihood of vehicle skidding (RoR).
o Average daily traffic (ADT) of HGVs.
Figure 6-4 Requirements, for Selecting the Minimum Containment Level for Safety Barriers at the Median or
Lateral Separating Islands Areas (FGSV, 2009 adjusted)
A decisive factor regarding the containment level of a safety barrier at median or lateral
separating islands is not whether a bridge abutment has been determined on the basis of
vehicle impact or not, since for such cases, safety barriers with containment levels L2 (H2) or
L4b (H4b), respectively, are provided. Bridge piers, either due to cross-section dimensions or
impact calculation, are not classified as structures at particular risk to third parties (hazard class
1).
Movements in the area of the mobile joints of bridges shall be addressed with special blocks
of contraction-expansion of the safety barriers.
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6.4.3.
Impact Severity
At areas of median and lateral separating islands, preference shall be given to the installation
of single-sided systems with separate action and if possible A impact severity class.
The advantage of these systems is that they operate independently of each other and therefore
have safety margins, since each system already has the minimum containment capacity
required.
6.4.4.
Working Width and Vehicle Intrusion
At median and lateral separating islands without obstacles, the maximum working width and
vehicle intrusion shall be determined in relation to the width of the central or separating island
and the width of the safety barrier, taking into consideration the inner shoulder width. In the
determination process of the required working width and vehicle intrusion, the type of the
safety barrier (double-sided or single-sided with separate or common action) as well as its
position (at the middle of the median island or offset from the median island) are also aspects
to be considered.
During the installation of two single-sided safety barriers at the edge line area of a median or
lateral separating island with separate action, the safety barriers positioned parallel to the first
edge line must not be placed within the working width of the safety barriers parallel to the
second edge line of the island.
In the case of different working widths, the largest one is the decisive. This restriction does not
apply to single-sided systems which have been jointly tested against impact in accordance
with SASO EN 1317.
Figure 6-5 and Figure 6-6 illustrate cases of double-sided safety barriers installed at the middle
of the median island and offset from the median island, respectively.
Figure 6-5 Double-Sided Safety Barrier Installed at the Middle of the Median Island (FGSV, 2009)
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Figure 6-6 Double-Sided Safety Barrier Installed Offset from the Median Island (FGSV, 2009)
Figure 6-7 and Figure 6-8 show cases of single-sided safety barriers with separate and
common action, respectively.
Figure 6-7 Single-Sided Safety Barrier with Separate Action Installed at the Highway’s Edge Lines (FGSV, 2009)
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Figure 6-8 Single-Sided Safety Barrier with Common Action Installed at the Highway’s Edge Lines (FGSV, 2009)
The (lateral) distance between the front face of the safety barrier and the highway’s edge line
shall be at least 0.50 m. This minimum distance may be reduced only in exceptional cases. The
provision of adequate visibility distances may require longer distances. To ensure adequate
stopping sight distances, it is acceptable either to select a lower in terms of height safety
barrier or to reduce the local posted speed. Failure to meet the stopping sight distance
criterion for a length that corresponds to a vehicle travelling with 0.5 s with the posted speed
(blind travel) shall be ignored.
Bridges with separate structures per direction of travel, with height difference along the
longitudinal joint and/or horizontal distance greater than 0.1 m, shall be treated as
independent structures.
In such cases with independent structures, special attention should be paid to the fact that the
higher structure may impose restrictions to the lower one in the selection of the working width
and vehicle intrusion.
On island areas of typical freeways and freeways with reduced characteristics (design speed
less than or equal to 110 km/h), and with the aim to increase road safety and reduce traffic
flow disturbances through less maintenance works, the selection process of safety barriers
should take into consideration the reduction of maintenance works and the elimination as far
as possible of respective repairs. This issue is critical for traffic volumes that exceed the value
of 1,500 veh/h for each remaining lane when lane blockage is imposed for road works. In this
case, the potential usage of the emergency lane may be required.
Maintenance and increased care is also required for cases where islands with safety barriers
are formed with planting. In general, planting of islands is not required from the road safety
point of view. All types of planting installations may reduce the available visibility lengths. In
addition, the maintenance requirements of planting may result in reduced road safety levels.
Compact (closed) VRS systems on islands that are not filled with planting soil may retain
detachable parts of the systems in the event of a vehicle impact resulting in an increase of the
road safety level, as opposed to the case of being filled with planting soil.
Nevertheless, when it is desirable to plant islands with compact safety barriers for aesthetic
reasons, the plantation of the island should be chosen appropriately so that it is low in height,
not dense, and has no high care requirements. The filling of islands with soil material should
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not result in an unintended development of planting. The planting of islands with compact
safety barriers generally increases the maintenance requirements of the islands and reduces
the road safety level of the highway.
Planting of islands with metal safety barriers should also be avoided. If island planting is
required (e.g. in order to prevent the dazzling of drivers), plants with slow growth as far as
possible and reduced maintenance needs should be selected.
At island areas with emergency openings, the same systems, as in the respective sections,
should be chosen to avoid transitions. Alternatively, portable safety barriers of equivalent
containment levels, allowing for quick disassembly may be selected. Such barriers should be
connected with transitions on both sides.
Existing islands with safety barriers of L1 (H1) containment level and where new obstacles are
installed, should be redesigned with safety barriers of L2 (H2), or L4b (H4b) containment levels.
As sliding over, or entering behind the safety barriers is excluded due to their configuration as
a continuous construction, the new safety barriers shall start 40 m before the obstacle and
terminate 30 m beyond it. In addition, the safety barriers shall also have at least the required
minimum test length (see Chapter 7).
6.5. Tunnel Areas
Longitudinal solid walls, when no protrusions or recesses are greater than 0.1 m, shall not be
regarded as obstacles. The same shall apply to tunnel safety nests which are less than 4.0 m in
length.
Tunnel portals, the beginning and end of piercing walls, protrusions or recesses which are
longer than 0.1 m and the end area of tunnel nests which are longer than 4.0 m shall be
considered as non-deformable obstacles perpendicular to the direction of traffic (hazard class
3), provided that their configuration, in case of potential vehicle impact, is not appropriate in
order not to impose risk to occupants.
Emergency exits, accesses and other installations of the tunnel safety system, which must not
be obstructed by the installation of a safety barrier, shall be excluded from the 4.0 m length
rule.
Regarding the determination of the safety barriers’ working width and vehicle intrusion,
Sections 5.4.2 and 5.4.3 apply, respectively.
Figure 6-9 shows the safety barriers formation at a tunnel portal layout.
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Figure 6-9 Safety Barriers Formation at a Tunnel Portal Layout (FGSV, 2009)
At the beginning of wall areas, tunnel portals, and at the end of tunnel safety areas (e.g., laybys), tunnels crash cushions may be installed (see Chapter 10).
At tunnel portal areas and tunnel safety areas inside tunnels (e.g., lay-bys), where pavement
and tunnel gauge transition is required, an exception regarding the inclination of the tunnel
wall from 1:12 to ≤ 1:3 (rise over run) can be made, in order to avoid the wall being considered
as an obstacle and also to avoid the need for a safety barrier to be installed. If this is not
possible, it is necessary to protect the wall (obstacle) by means of a suitable safety barrier or
crash cushion.
The tunnel portals shall be designed in accordance with Figure 6-9 to ensure that safety
barriers can be installed properly in accordance with the above provisions. The design of the
safety barriers shall therefore be timely integrated into the tunnel design and the operating
mode of emergency services. At areas of construction transitions at the tunnel portals, the
widths of the necessary emergency pedestrian access runways must be respected.
At tunnel portals, special attention shall be paid to the rapid disassembly of the safety barriers
in order to provide emergency openings or to the selection of appropriate systems for this
purpose (e.g., portable safety barriers, or other special devices).
6.6. Selection Process Flowchart
Figure 6-10 is used as the basis to determine the minimum containment level required by a
safety barrier. The steps to be followed are as follows:
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Step 1: Identification of the hazardous location and classification of the associated risk [e.g.
hazard class 2 (risk to third parties) or hazard class 3 (particular risk for vehicle occupants)].
Step 2: Determination of the distance of the hazardous location from the highway edge line
(decisive distance).
Step 3: Determination of the critical distance depending on the hazard class to which the
obstacle belongs (AE for hazard class 1 and 2 or A for hazard class 3 and 4), the posted speed
and the height difference between the highway edge line and the inner boundary of the
obstacle.
Step 4: Determination of factors affecting traffic: posted speed, average daily traffic (ADT) of
all vehicles, ADT of HGVs and increased frequency and/or likelihood of vehicle skidding (RoR).
ADT of HGVs refers to the contribution of trucks over 3.5 t gross weight and buses to traffic.
Step 5: Determination of the minimum required containment level of the safety barrier in
relation to the above steps.
Step 6: Determination of the working width class, and where applicable, vehicle intrusion class
(case HGV for containment level greater than L1 (H1)) of the safety barrier with reference to
the lateral distance of the safety barrier’s front face from the obstacle. A system with a higher
containment level than required may be selected if the distance between the front face of the
safety barrier and the obstacle is short.
Step 7: Determination of the impact severity class of the safety barrier. In general, systems
with class A impact severity are preferred for safety reasons when the other constraints are
identical. If there are no systems with class A impact severity, systems with class B impact
severity shall be selected. Class C impact severity shall be selected only in very exceptional
cases and where the required performance is not met by systems with impact severity of class
A or at least class B.
The above are summarized in the flow chart of Figure 6-10, where initially an assessment
regarding the need for installing safety barriers is carried out for a given area, followed by the
determination of the containment level, working width, vehicle intrusion, and impact severity
classes.
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Figure 6-10 Procedure for the Selection of Performance Classes for Safety Barriers (FGSV, 2009 adjusted)
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7. Implementation Lengths
7.1. Highway Edge Line Areas
In order for the safety barrier to be effective, a given minimum total length of LA shall be
required. This minimum length of LA shall be specified in the test report of each system
according to SASO EN 1317.
In addition to the above, the length of the safety barrier before the hazardous location shall
be at least equal to LB (Table 7-1 and Figure 7-1, Figure 7-2) so that vehicles skidding (RoR)
from their path
•
•
and slide along the safety barrier and its terminals not to strike the obstacle, when its
lateral distance is less than 1.5 m.
not to drive behind the safety barrier and strike obstacles (positioned behind) or enter
a protected area. This case applies when it is not possible for the vehicle to slide against
the safety barrier.
Sliding against the safety barrier applies in general for cases where the terminal is dropped.
The length LB referring to the vehicle passing behind the safety barrier shall only be taken into
account if a vehicle can actually pass behind a safety barrier and access the hazardous location.
In case of embankments the sliding criterion is not decisive for the design of the safety barrier
since a vehicle that slides against the safety barrier, when it reaches the hazardous location
(height > 3 m) does not strike any obstacle, but simply continues to increase the height
difference from the ground. However, this case applies only for hazardous locations on
“embankment slopes” and not for respective locations of bridge and retaining wall edge lines
which concern vehicle vertical drop. When the edge line of a bridge or retaining wall is within
the distance of 1.5 m from the front face of the safety barrier, then the criterion of vehicle
sliding against the barrier applies.
Where a safety barrier with higher containment capacity is installed locally along a highway
section equipped with a continuous safety barrier (e.g. a location with higher hazard class) it
is required to check the possibility for vehicle passing behind the barrier. The reason is that,
when a heavy vehicle strikes the safety barrier with the lower containment level, its failure in
terms of performance cannot be excluded, which will result to striking the object with the
higher hazard class. Therefore, the rules for preventing the vehicle from passing behind the
safety barrier also apply in this case, unless this can be excluded.
There are three possibilities for the installation of safety barriers:
•
Positioning of the safety barrier parallel to the highway edge line with optional
reduction of the containment capacity
Before and after the hazardous location, the safety barrier must be of a given length in
order to be effective. On two-lane rural highways (single carriageway), the length of
the safety barrier before and after the obstacle shall be at least equal to LB (Figure 7-1,
Figure 7-3). On one-way traffic single carriageway highways, the length of the safety
barrier after the obstacle shall be at least equal to 20 m. On divided highways, before
the obstacle, the length of the safety barrier shall be equal to LB and after the barrier
equal to at least 30 m (Figure 7-2, Figure 7-4).
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A reduction regarding the containment level of the safety barrier by one class at the
area of the LB implementation length is possible by a length of 0.5LB before the
hazardous location (Figure 7-1, Figure 7-2, Figure 7-3, and Figure 7-4). For example,
the containment level can be reduced after the length of 0.5LB from L4b to L2.
Therefore, if safety barriers are to be connected in a different construction and/or
dynamic operability, provision shall be made for transitions, the cost of which shall be
taken into account before the restraint capacity is reduced accordingly.
The length of a safety barrier with the reduced containment level by one class shall be
at least equal to the minimum test length (LA) of the system. Therefore, it is possible
the total length of safety barriers with reduced containment capacity to be greater than
the respective length without reducing the containment capacity. In principle, a
reduction in containment capacity makes sense when the required length of LB is at
least 100 m.
On divided highways it is possible to reduce containment level of the installed barrier
15 m after the obstacle (Figure 7-2, Figure 7-4).
For cases where it is not possible to comply with the above lengths, solutions similar
to the criteria of the present Guidelines should be sought. In this context, there are two
options:
i. Reducing the barrier lengths to an acceptable minimum length. The
abovementioned lengths of 20 m or 30 m after the obstacles for two-lane rural
or divided highways respectively shall not depend on the performance of a
safety barrier. These lengths shall be derived from the impact tests of SASO EN
1317 according to which the vehicle's point of impact is in a position
corresponding to 1/3 of length LA, where as a result, the lengths of 20 m and
30 m are obtained as standard lengths. With reference to these lengths it
becomes clear that the selection of shorter lengths results to questioning the
operability of the barrier.
ii. Selecting a vehicle restraint system or a protection against an individual
obstacle, provided that this ensures that a vehicle does not impact the obstacle.
•
Positioning the safety barrier at an angle (skewed)
If the safety barrier is positioned at an angle of 1:20 to the highway’s edge line and in
exceptional cases up to 1:12 (rise over run) (Table 7-1) it is possible to reduce the length
of LB. The safety barrier shall be positioned parallel to the highway’s edge line before
the location of the obstacle to a length of at least 10m on two-lane rural highways and
15 m on divided highways (Figure 7-3, Figure 7-4).
In the case where the starting of the safety barrier is attached to a cut slope, its length
before the hazardous location does not need to be equal to LB. In this case the safety
barrier can be mounted at an angle of 1:20 and in exceptional cases 1:12 and connected
to the cut slope.
•
Βlocking space behind the safety barrier
Where driving behind the safety barrier is not possible, e.g. embankment with steep
slope, and the possibility of a vehicle sliding along the safety barrier is excluded, the
length LB shall be reduced to 40 m according to Table 7-1.
Such examples are as follows:
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o
o
The ground slope from flat road becomes inclined, e.g. embankment slope
height > 3 m with slope > 1:3 (rise over run). Not applicable to bridge and
retaining wall edge lines.
Obstacle at the end of a sharp curve. If a safety barrier is installed at a 40 m
length before the hazardous location, it shall not be possible to strike the
obstacle.
Table 7-1 Required Length LB against Sliding and Driving Behind (FGSV, 2009)
Positioning of the safety barrier (SB)
Criterion
Highway Type
Slide along the SB with an Two-lane rural
obstacle positioned ≤ 1.5
highway
m from the front face of
Divided highway
the SB
Driving behind the SB
Parallel to the
Laterally
highway
skewed 1/20
Not possible to
drive behind SB
100 m
-
-
140 m
-
-
Two-lane rural
highway
80 m
60 m
40 m
Divided highway
100 m
60 m
40 m
Figure 7-1 Minimum Lengths of Safety Barriers for Two-Lane Rural Highways (Single Carriageway) (FGSV, 2009)
Figure 7-2 Minimum Lengths of Safety Barriers for Divided Highways (FGSV, 2009)
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Figure 7-3 Skewed Positioning of Safety Barriers before Obstacle for Two-Lane Rural Highways (Single
Carriageway) (FGSV, 2009)
Figure 7-4 Skewed Positioning of Safety Barriers before Obstacle for Divided Highways (FGSV, 2009)
In the case of junctions with two-lane rural highways or forest roads or cycle routes where the
stated above minimum safety barriers lengths cannot be respected, then, in combination with
the prevailing local conditions, the following alternatives shall be examined:
•
•
•
•
When the LB length is not respected, then the restraint system shall be installed
adapted to local conditions by selecting shorter lengths but in such a way that the risk
of sliding against the barrier or driving behind it is very low, and
When the required length LA is not respected, a restraint system with a shorter
minimum operating length shall be selected, or
When the required length LA is not respected a restraint system with the next highest
containment capacity and with reduced minimum lengths adjusted to local conditions
shall be selected, or
Depending on local conditions, when the LA or LB lengths cannot be met the feasibility
of installing crash cushions shall be considered.
In the above cases, attention should be paid to the fact that these constructional
configurations have been chosen in such a way that the connected terminals are capable of
taking on the developed tensile and compressive forces.
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The terminals are not included in the installation length L of the safety barriers.
In cases where safety barriers are installed in ditches, and in order to ensure the operability of
the barrier, the required minimum and maximum installation height above the support surface
shall be respected (see also Installation Details Section). The safety barrier terminal shall be
sufficiently anchored to the sloping area.
When short gaps arise between successive portions of safety barriers in which the arrangement
of safety barriers is not required, consideration shall be given to whether the arrangement of
safety barriers is appropriate within the length of such gaps.
When connecting different types of safety barriers, which do not differ significantly, transition
elements are used. For cases where two different types of safety barriers do not have suitable
transitional connection brackets, then one or more different safety barrier types can be
installed, which can be connected to each other by suitable and acceptable brackets, thus
creating a transitional system of consecutive safety barriers between the two original ones.
In every case, the rules stated in Chapter 11 (Transitions) shall be respected.
The individual barrier(s) inserted between the original safety barriers, in order to form this
appropriate transitional barrier system, may have a shorter than the minimum required
operating length LA. This reduced operating length LAred is given in Table 7-2 (see also
Installation Details Section), as a function of the containment level of safety barrier. The length
of each transition is added to the lengths of Table 7-2.
Table 7-2 Minimum Interpolated Safety Barrier Lengths LAred to Establish a Transitional Barriers System (Bast,
2020a)
Safety Barrier Containment Level
LAred (m)
N2
12
L1
16
L2
20
(L3)
(24)
L4b
28
7.2. Bridge and Retaining Walls Areas
Bridge areas shall be fitted with safety barrier lengths as referred to the previous section
(Section 7.1), in particular with respect to LB. Therefore, the area where the safety barrier is fully
operational shall be positioned adequately enough from the beginning and ending of a bridge
or a retaining wall as to prevent a vertical drop (Figure 7-5, Case A).
In this case, no specific reference is made for assessing the barrier’s length due to a vertical
drop, since this depends on local conditions, such as embankment height, location of the
transition length from the structure, etc. When the distance of the bridge or retaining wall
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edge line is less than 1.5 m from the front face of the safety barrier, then the criterion of vehicle
sliding against the barrier applies (see Section 7.1).
This implies that safety barriers along a bridge shall generally be extended beyond the bridge
length. If this is not possible, the length of the safety barrier may be equal to the length of the
bridge or retaining wall if it is connected to a safety barrier with the same containment level
(Figure 7-5, Case B). For transitions see Chapter 11. Regarding lengths of connecting structures,
Section 7.1 applies.
Movements in the area of the mobile joints shall be addressed by contraction-expansion
portions of the safety barrier in order to avoid damages to the safety barrier.
Before the beginning and after the end of the bridges, their curbs shall be fitted in terms of
height to the typical cross section of the highway through a transition gradient of 1:10 (rise
over run).
The performance classes of regarding terminals are defined in Chapter 9.
Figure 7-5 Safety Barriers on Bridge Areas (FGSV, 2009)
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At the physical gore areas of separating traffic islands on bridges, in order to prevent the risk
of a vertical drop, the installation of crash cushions shall be considered (Figure 7-6). The
required performance classes are defined in Chapter 10.
At freeway interchange areas, the containment level of a safety barrier depends on the
respective risk classification of the hazardous location. The structure edge line of the main
carriageway (main direction of travel) requires a L4b containment level provided that there is
no parallel distributor road separated from the main carriageway by a safety barrier. At the
edge lines of overpassing structures on ramps above main carriageways with two or more
lanes, or structures on ramps with two or more lanes, containment level of L4b may be
required.
At the area of lateral bridge roadside formations which are equipped with walls (protection
against overhead electrical networks, sound barriers, etc.), such walls are classified as obstacles.
The working width and possibly the vehicle intrusion of the safety barrier shall not be greater
than the distance of the safety barrier from these obstacles. The lateral configuration in terms
of dimensioning for such cases shall consider the required width of the safety barrier.
Figure 7-6 Exemplary Use of Crash Cushions on Separating Traffic Islands on Bridges (FGSV, 2009)
When separating a paved surface from a special pedestrian path or a cycling route on
structures, care must be taken to ensure that the safety barriers do not have sharp edges or
projections, which would pose a risk to cyclists or pedestrians (preferably use of concrete safety
barriers, or specially designed steel barriers). Specific additions to the barriers, in order to
protect such vulnerable road users, may be used if the overall systems are certified in terms of
performance as an integrated SASO EN 1317 system.
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Since safety barriers at structure areas must be extended beyond their length to ensure their
operability (e.g. by changing from ramming systems to anchored systems or alternatively by
expanding the structure by means of foundation slab), close collaboration and coordination
between the structural engineer and the highway designer is required.
In case a safety barrier needs to be anchored on a tie-in beam, whereas its arrangement is not
certified for impact severity in accordance with SASO EN 1317, but the safety barrier is certified
for vehicle parapet use, the manufacturer is obliged to submit a structural adequacy statement
prepared by a certified structural engineer, based on the results of the physical test (e.g. force
measurements).
On bridges with a free span of less than 10 m, on retaining walls of less than 25 m in length
and on sewers as well as for vertical drop heights of less than 2 m, Table 6-1 shall not apply.
Railings are generally classified in hazard class 3.
Safety barriers and railings on structures over or adjacent to electrified railways shall be
protected against electrical conductivity on them. Depending on the position of the railway
and the electrical supply devices in relation to the bridge, electrical insulation joints for the
safety barriers after the end of the bridges and electro-insulating fields consisting of two
electro-insulating joints at a distance of at least 2.50 m for railings shall be required. Relevant
electrical insulation devices for safety barriers and bridge railings shall be made available under
the responsibility of the competent railway operating body, which shall be integrated into the
grounding system of the structure.
If during the impact test the safety barrier was fitted with a railing which was part of the
restraint capability then the railing is an integral part of the safety barrier, which shall not be
ignored during the vehicle restraint systems design. In such cases, the installation of such a
safety barrier on the median or lateral separating islands must include the railing.
The railings shall be subject to the standards SASO EN 1317, and Structural Standards as
described in Section 11.7.2 of SHC 310 (Bridges and Tunnels Design) and Chapter 21 of SHC
402 (Construction of Bridges and Tunnels).
If structures are more than 20 m in length between wing wall edges, the railings shall be fitted
with a cable of 20 mm in diameter in accordance with EN 12385-4 6x19- or 6x37-SFC 1770 A
sZ. Structures which do not have a safety barrier, shall be fitted with railings whose ends shall
be dropped or curved to prevent them from entering to vehicles in case of impacts.
The typical heights of railings are:
•
•
•
1,000 mm for vertical drop height < 12.00 m.
1,100 mm for vertical drop height ≥ 12.00 m.
1,300 mm if along the structure a cycling route or a common pedestrian path and
cycling route is passing through.
The width of the railings shall be at least 120 mm on highway bridges, where on pedestrian
bridges this width may be reduced to at least 80 mm.
The loads regarding railings shall be as specified in Section 11.8.2 of SHC 310 (Bridges and
Tunnels Design).
Manufacturers of railings shall submit the relevant performance certificates in accordance with
EN 1090-1 and for welds the certificates in accordance with EN 1090-2 for steel and EN 10903 for aluminum railings respectively.
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On bridge edge lines the height of a railing should comply with the following rule:
𝒉𝒓𝒂𝒊𝒍𝒊𝒏𝒈+𝒑𝒓𝒐𝒕𝒆𝒄𝒕𝒊𝒐𝒏 = 𝒉𝒔𝒂𝒇𝒆𝒕𝒚 𝒃𝒂𝒓𝒓𝒊𝒆𝒓 + 𝒉 − 𝒃 − 𝟎. 𝟎𝟓 ≥ 𝒉𝒎𝒊𝒏
Equation 7-1
where:
hrailing+protection = minimum required railing height including additional drop protection height
(m) ≤ 2.00 m
hsafety barrier = safety barrier height above the emergency corridor surface (m)
h = minimum railing height depending on the drop height (m) 1.00 m or 1.10 m
b = horizontal distance between rear side of the safety barrier at the height of its upper edge
and front edge of the railing (m)
hmin = minimum railing height as mentioned above (m).
In order to limit the height of the railing between safety barriers with the same characteristics,
the ones with the lowest height shall be selected. The total height of a railing and the drop
protection shall not exceed 2 m above the surface of the lateral bridge roadside formations.
The height of the railing shall be limited to 1.20 m on bridge edge lines with a L2 containment
level. Regarding the height of the safety barrier, the following apply:
𝒉𝒔𝒂𝒇𝒆𝒕𝒚 𝒃𝒂𝒓𝒓𝒊𝒆𝒓 ≤ 𝒉𝒓𝒂𝒊𝒍𝒊𝒏𝒈 − 𝒉 + 𝒃 + 𝟎. 𝟎𝟓
Equation 7-2
where:
hrailing = selected railing height ≥ hmin and ≤ 1.20 m.
In certain cases, which can be properly justified, solutions may be chosen by way of exception
from the above, after assessing road safety data and local restrictions.
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8. Interruption Areas
Interruptions (discontinuities) of safety barriers shall be allowed only in justified cases. In such
cases they should be as short as possible. Moreover, other traffic safety requirements such as
visibility, clearance, etc. should also be taken into account.
Areas of interrupted safety barriers should be avoided particularly in road sections with small
horizontal radii. At highway intersection areas, it should always be considered whether the
installation of safety barriers is not necessary.
At areas with safety barriers interruptions, the safety barriers shall overlap, in accordance with
Figure 8-1.
Figure 8-1 Interruption of Safety Barriers for Approaches (FGSV, 2009)
Where there is no possibility of an incident where a vehicle runs off the road at safety barrier
interruption area, the safety barrier may be placed at an angle (skewed) and connected to
leading and trailing terminals (Figure 8-2 and Figure 8-3). In such cases, the safety barrier and
the leading and trailing terminals shall be placed at an angle of 1:12 (rise over run).
Figure 8-2 Interruption of Safety Barriers with Skewed Positioning of Terminals (FGSV, 2009)
Figure 8-3 Interruption of Safety Barriers with Leading - Trailing Terminals (FGSV, 2009)
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The curved (rounded) configuration of the safety barrier can prevent the vehicle being
penetrated in hazardous locations. The safety barriers shall be curved with as wide a radius as
possible (Figure 8-4 and Figure 8-5). For this reason, the safety barriers can be installed at a
skewed angle of 1:12 (rise over run). In any case, a curved safety barrier shall be attached to
leading and trailing terminals or to a safety barrier. The curvature of a safety barrier shall ensure
its operability. More details on such curved sections are provided in Chapter 19.
Figure 8-4 Interruption of Safety Barriers with Skewed Positioning of Barriers and Curved Area (FGSV, 2009)
Figure 8-5 Interruption of Safety Barriers without Skewed Positioning of Barriers and Curved Area (FGSV, 2009)
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9. Terminals
Leading and trailing terminals must be connected to the main safety barrier in such a way that
the operational characteristics of one system do not adversely affect the respective
characteristics of the other. The manufacturer of the safety barrier terminals shall submit
evidence of their basic characteristics.
The performance of terminals shall be determined, in accordance with the standard
SASO EN 1317, by the following criteria (currently voluntary requirements):
•
•
•
•
Performance class.
Vehicle exit box class.
Permanent lateral displacement class.
Impact severity class.
The requirements for the performance classes of terminations are given in Table 9-1.
Table 9-1 Requirements for Leading and Trailing Terminals of Safety Barriers (FGSV, 2009)
Highway Class
Performance Class
Two-lane rural highway
at least T80 A (before P2 A)
Divided highway
at least T80 U (before P2 U)
NOTE: A: Terminals in both directions of travel, U: Terminals in one direction of travel.
The classes of the vehicle exit box and permanent lateral displacement shall be determined
according to local conditions. The class of permanent lateral displacement shall be selected so
that the deformed leading and trailing terminal does not extend beyond the internal painted
edge line boundary of the highway surface.
Impact severity class A provides greater safety to the vehicle occupants than Impact severity
class B and shall be preferred when the other conditions remain the same.
Cases where no terminals are available which have undergone a physical impact test in
accordance with SASO EN 1317, for the selected safety barriers, shall be treated as follows: An
investigation shall be carried out, whether a solution with terminals compatible with another
safety barrier type, which have been subjected to an impact test in accordance with SASO EN
1317, are available and moreover, whether a connection by an appropriate safety barrier
transition is technically feasible and at the same time more economical.
The detailed vehicle restraint system design and the project tender call shall include the criteria
for the selection of terminals as an integral part of the vehicle restraint system design.
The terminals can be formed with or without dips. Depending on the construction method of
the terminal, consideration should be given to whether sliding against the safety barrier and
terminal system is effectively avoided. This aspect is critical when determining the required
length of a safety barrier that precedes or follows a terminal.
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Safety barriers shall always be accompanied with leading and trailing terminals. This
requirement is particularly critical at the areas of lateral and median separating islands
(Figure 9-1, Case A and Case B, respectively). The safety barrier length between the end of the
leading terminal and the obstacle shall be at least LB, if not a crash cushion shall be installed
(see Chapter 10).
Figure 9-1 Separating Islands with Safety Barriers and Leading Terminals (FGSV, 2009)
At the areas of lateral separating islands, where it is necessary to place safety barriers on both
pavement edge line areas, the leading terminals shall be at least 3 m apart (Figure 9-2). Also
for this case, the safety barrier length between the end of the leading terminal and the obstacle
shall be at least LB, if not a crash cushion shall be installed (see Chapter 10).
At medians with safety barriers interruption areas, provision shall be made for installing
leading and trailing terminals.
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Figure 9-2 Lateral Separating Island with Safety Barriers and Leading Terminals on Both Pavement Edge Line
Areas (FGSV, 2009)
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10. Crash Cushions
Crash cushions shall be connected to safety barriers that follow with provision the operational
characteristics of one system not to adversely affect the respective characteristics of the other.
The manufacturers of crash cushions shall submit evidence regarding the operational
characteristics of both protective devices, with reference to the particular crash cushion.
Crash cushions shall meet the requirements of SASO EN 1317. The performance of crash
cushions shall be determined in accordance with SASO EN 1317 based on the following criteria:
•
•
•
•
Performance class vs posted speed.
Permanent lateral displacement class.
Vehicle redirection class.
Impact severity class.
The requirements regarding the performance classes of crash cushions are shown in Table
10-1.
Table 10-1 Performance Classes Crash Cushions with Reference to the Posted Speed (FGSV, 2009)
Vposted (km/h)
Performance Class
50 (R)
80 (R)
100 (R)
110 (R)
50
x
-
-
-
60
-
x
-
-
70
-
x
-
-
80
-
x
-
-
90
-
-
x
-
100
-
-
x
-
> 100
-
-
-
x
NOTE: (R): Returning.
The permanent lateral displacement and vehicle redirection classes shall be indicated in the
impact test report and the requirements shall be determined in accordance with local
conditions and available lateral space. The permanent lateral displacement class shall be
selected in such a way that the crash cushion that deforms, does not extend beyond the
internal painted edge line boundary of the highway surface.
The geometric configuration of the crash cushion (parallel, trapezoid) shall be adjusted to the
geometric arrangement of the installation area.
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Impact severity class A provides greater safety to the vehicle occupants than Impact severity
class B and shall be preferred when the other conditions remain the same.
For cases of lateral or median separating islands where the length LB is not available at the
starting area of the safety barrier, a crash cushion shall be installed (Figure 10-1).
Figure 10-1 Separating Islands with Safety Barriers and Crash Cushions (FGSV, 2009)
At areas with isolated obstacles, consideration should be given to whether the installation of
crash cushions offer more advantages than the installation of safety barriers. Comparing both
protective devices, crash cushions have the following advantages:
•
•
•
Crashes with less consequences on average.
Availability of lateral space for emergency vehicles or collision avoidance maneuvers.
More efficient facilitation for road operation and maintenance services.
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At medians with safety barriers interruption areas, when an obstacle is positioned to up to
50 m ahead and the posted speed cannot be reduced to 60 km/h provision should be made
for installing crash cushions.
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11. Transitions
Transitions of safety barriers are located at areas where different barrier types in terms of
construction and/or dynamic operability are to be connected in an operationally acceptable
way. The performance of safety barriers shall be determined in accordance with
SASO EN 1317 (currently voluntary part) based on the following criteria:
•
•
•
Containment level.
Working width class.
Impact severity class.
The containment capacity of safety barriers transitions is a function of the respective
containment capacity of the attached safety barriers and shall be determined in accordance
with Table 11-1.
Any impact tests according to SASO EN 1317 shall be related with the connecting safety
barriers. Transitions which have been tested for impact according to SASO EN 1317 are a
criterion for selection and preference against respective transitions without physical testing.
During the vehicle restraint system design the criteria for selecting transitions shall be taken
into account in conjunction with the criteria for selecting the connecting safety barriers.
Table 11-1 Containment Levels of Safety Barriers Transitions (FGSV, 2009)
Transition to a
protective device
with
containment
level
L1
L2
L4b
L1
L1
L1
L2
L2
L1
L2
L2
L4b
L2
L2
L4b
From a protective
device
with containment level
The maximum working width of a transition depends on local conditions. The impact severity
class of a transition shall not exceed either of the respective impact classes of the safety barrier
to which it is attached. In general, impact severity level A represents a lower intensity for the
occupants of a vehicle that leaves the roadway than impact severity level B. It should receive
preference in comparable situations.
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Connections of safety barriers to special structures, e.g. retaining walls, rock traps, etc. are
considered and designed as safety barriers transitions based on their containment level to
interact with the rigid surface, assuming zero dynamic deflection and working width below
0.6 m (D = 0, W1, see Figure 5-2).
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12. Portable Safety Barriers
12.1. General
Temporary (portable) safety barriers are mandatory to be installed at long term work zone
areas, for assuring traffic separation, guidance and generally safe vehicle motion. Additional
information on the use of temporary safety barriers is provided in Section 4.22 of SHC 305
(Highway Facilities and Utilities Design – Work Zone Design).
The portions of the temporary safety barriers shall be connected to each other and placed, in
accordance with the manufacturer’s instructions, in order to provide protection both to
adjacent traffic and construction/maintenance activities behind them. If the temporary safety
barriers are not connected together, in the event of a vehicle collision with them, their
displacement and/or their overturn should be expected according to the speed, mass and
angle of impact of the vehicle.
12.2. Containment Levels
The areas for installing temporary safety barriers are shown in Figure 12-1, where the
requirements to be fulfilled are given in Table 12-1.
Figure 12-1 Installation Area of Temporary Safety Barriers (FGSV, ZTV, SA, 1997)
At areas A and B the lateral displacement of the temporary safety barriers shall not be greater
than their distance to the area occupied by the work zone personnel, materials or equipment.
No special requirements are laid down for the area marked with C.
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Table 12-1 Containment Level and Working Width of Temporary Safety Barriers (FGSV, ZTV, SA 1997)
Area for positioning temporary safety barriers
(based on Figure 12-1)
Minimum
Containment
Level
(EN 1317)
Working
Width
(EN 1317)
A
Between construction site and oncoming
traffic
T2(1)
≤ W4
B
Between construction site and the parallel
oncoming traffic
T1(1)
≤ W4
C
Between construction site and outgoing
traffic
D
Between opposing directions of travel
Between opposing directions of travel
E
at the diversion area
Dynamic
Lateral
Displacement
(m)
no protective system required
T1(2)
≤ W4
≤ 0.50
T2(2)
≤ W4
≤ 0.50
NOTES:
1. Where a greater containment level is required, areas A and B shall be provided with barriers of L1 and T3
containment capacity respectively. The working width is determined in accordance with the local conditions
based on EN 1317.
2. For cases where the truck traffic is high and there is a risk of truck involvement in an accident, e.g. on downhill
sections, a system with a T3 containment capacity may also be selected provided that the available width of the
highway surface is sufficient. In general higher containment levels are required where the circumstances require
them (e.g. temporary speed limit of 100 km/h and truck involvement).
The temporary safety barriers shall be examined by impact tests, regarding potential
displacements, safety against breakage and the provision of protective measures for both
traffic participants and third parties.
12.3. Working Width
As the selection process of an appropriate temporary safety barrier is a function of its available
distance from the construction site and the available width of the separating island, the
working width has a particularly important role.
The width of the separating island between the opposite traffic directions depends on the
design width and/or the construction width of the temporary safety barrier, where:
•
•
Structural width is the maximum width of the cross section of the temporary safety
barrier.
Design width is the horizontal distance between the inner edges of the retro-reflective
elements at the bottom level area of the temporary barrier forming an angle of not
more than 5 o with its base. If the angle between the lower level area and the inner
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edges of the retro-reflecting components is greater than 5 o, the construction width
corresponds to the design width (Figure 12-2).
The design width shall correspond to the required width of the separating island.
Figure 12-2 Design and Structural Width of Temporary Safety Barriers (FGSV, TL, 1997)
12.4. Passive Protection
In view of the particular conditions prevailing in the work zone areas, in addition to the working
width of the proposed temporary protective devices, the dynamic lateral displacement shall
be indicated as well. Between the opposite traffic flows, the maximum permissible value of the
dynamic lateral displacement is 0.50 m, regardless of the working width.
It is therefore not permissible, when a vehicle impacts a temporary safety barrier, to cause
damages to the vehicle severe enough so that driver loses control of the vehicle.
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13. Motorcyclists Protection
The physical damages to motorcyclists diverted from their direction of travel when impacting
protective devices can be substantially reduced by:
•
•
Safety barriers with declared additional protection for motorcyclists.
Suitable additional structures on the safety barrier.
The performance of systems for the protection of motorcyclists shall be determined according
to the European standard SASO EN 1317, TS 17342, 2019-10 from the following criteria:
•
•
Speed class.
Impact severity class.
Protective devices which are meant to provide additional protection for motorcyclists shall be
designed in such a way that:
•
•
The components of the system do not have sharp edges, so as to significantly reduce
the crash impact of a motorcycle against them.
By means of additional constructions to cover critical parts of the protective devices or
to prevent cross-sliding under the system with uniform longitudinal surfaces/coatings
without edges and protrusions.
Additional structures on steel restraint systems may be;
•
•
•
Mantles on the support pole of the protective device of foam plastics, which
significantly reduce the consequences during the impact of a human body against the
safety barrier (effective only at low speeds).
An additional slide protection blade placed lower than the main safety barrier groove
Other structures which will be certified as suitable for a specified safety barrier based
on impact tests according to SASO EN 1317.
Such relevant systems are divided into two categories:
•
•
Class I: Safety barriers with protection against sliding below the safety barrier, which
have been subjected to an impact test in accordance with SASO EN 1317 or modified
and have undergone a specific impact test in accordance with TS 17342:2019-10.
Class II: Safety barriers with protection against sliding below the safety barrier, which
have been subjected to an impact test or modified in accordance with SASO EN 1317.
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14. Installation Details
14.1. General
Additional requirements or specific details regarding VRS installation shall be specified in the
Technical Specifications of the project or in the Tender Documents.
The contractor shall ensure that assemblies regarding various parts of the protective devices
are performed by personnel with the necessary technical knowledge.
Before commencing the protective devices installation works, the contractor shall be informed
on the location and routing of all types of public utilities (ducts, cables, etc.). The contractor is
obliged to ensure that the installation of protective devices will not result in damages.
For cases where the highway roadside terrain, is located at dessert areas, only steel or cable
barriers shall be allowed in order to avoid sand accumulation on the traffic space.
The supporting surface of a protective device shall be sufficiently durable and stable. Its
configuration shall ensure the operability and performance of the protective device, according
to the respective installation instructions.
The area in front of and below the protective device shall be reinforced at least as well as the
surface of the unpaved shoulder (sufficient to support a passenger vehicle).
In the area behind the protective device (operational area) the foundation surface shall be
stabilized or reinforced in such a way that the protective device behaves as in the impact test.
In the Technical Specifications of the restraint systems works, there shall be a detailed
description of both the existing and the potentially under development foundation surface of
the protective device.
If the existing or under development support surface does not meet the requirements of the
installation instructions, the contractor shall construct and configure the support and
foundation surface appropriately.
The following sections address issues related to the installation height of the protective devices
under various conditions.
14.2. Level Unpaved Shoulder
The protective devices installed on typical road sections (excluding intersection and
interchange areas) are subject to impact tests on level ground in principle. The height “hP” of
the protective device over the highway surface during the impact test shall be indicated in the
relevant test reports (Figure 14-1). When installing the protective device under real conditions,
where the support surface is inclined, a vertical adjustment regarding the support surface or
height of the protective device may be required.
The height “hE” refers to the front face height above the installation surface of the protective
device. In the case of a level ground between the highway surface and the protective device,
the measured installation height “hE” of the protective device shall be equal to the respective
test height “hP”.
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Figure 14-1 Height of Protective Device (hP) during the Impact Test (FGSV, 2017)
14.3. Inclined Unpaved Shoulder
On inclined unpaved shoulder areas, the installation of protective devices is in accordance with
the grade “s” of the unpaved shoulder or median island, the distance “a” between the front
face of the protective device and the paved edge line, and the type of protective device.
The following provisions shall apply to a protective devices which have been subjected to level
impact tests (superelevation ≤ ± 2.5 %).
For special cases where the protective devices have undergone impact tests on greater
superelevation rates, the permitted deviations shall be assessed on a case-by-case basis and
in relation to the behavior of the protective device.
The stated values of superelevation rates stated in the next sections, refer to relative values
between the highway surface and the unpaved shoulder.
14.3.1. Steel Protective Devices Anchored
Steel protective devices with anchored poles shall be installed vertically.
The installation height of the protective device with anchored poles depends on the
superelevation rate of the unpaved shoulder “s” (s ≤ 12 %) and the distance “a” between the
front face of the protective device and the paved edge line.
Table 14-1, Figure 14-2, Figure 14-3 show the installation heights for protective devices
referring to “a” values up to and greater than 0.6 m, respectively, for downgraded unpaved
shoulder.
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Table 14-1 Installation Height of Steel Protective Device, Anchored for Downgraded Unpaved Shoulder (FGSV,
2017)
Unpaved Shoulder
Superelevation Rate
Distance between front
face of protective device
(relative value between
and paved edge line
highway surface and unpaved
shoulder) (%)
Protective Device
Installation Height
Negative Superelevation Rate
(downgrade)
a ≤ 0.6 m
hE = hp +
s ≤ 12 %
a > 0.6 m
hE= hp
as
100
Figure 14-2 Height of Steel Protective Device, Anchored, Downgraded Unpaved Shoulder (a ≤ 0.6 m) (FGSV, 2017)
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Figure 14-3 Height of Steel Protective Device, Anchored, Downgraded Unpaved Shoulder (a > 0.6 m) (FGSV, 2017)
For protective devices with positive slope (upgrade) up to 12 % their installation height “hE”
shall follow the installation height during the impact test “hp” (Figure 14-4, Figure 14-5).
Figure 14-4 Height of Steel Protective Device, Anchored, Upgraded Unpaved Shoulder (FGSV, 2017)
On an inclined median island and a double-sided protective device, the installation height of
the protective device shall be determined in accordance with Figure 14-5.
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NOTE: hE measured at axis of protective device.
Figure 14-5 Height of Steel Double Sided Protective Device, Anchored, Upgraded Unpaved Shoulder (FGSV, 2017)
14.3.2. Temporary Steel and Precast Concrete Protective Devices
If the foundation base is constructed simultaneously with the temporary protective device,
and the precast concrete protective device, then the foundation base shall be constructed in
such a way that the protective device can be positioned vertically (Figure 14-6).
In the case of existing surfaces, the temporary and precast concrete protective devices may be
installed, up to a superelevation rate of s ≤ 6 % (positive or negative), perpendicular to the
foundation surface. The installation height of the protective devices in this case (hE=hp) shall
be determined by reference to the ground in front of them (Figure 14-7).
In cases of superelevation rates greater than 6 % (negative or positive) on unpaved shoulders
and islands, the support surface shall be adjusted in consultation with the Managing Authority.
Otherwise, other appropriate measures need to be taken.
Figure 14-6 Construction of Foundation Base for Vertical Temporary Steel and Precast Concrete Protective
Devices Installation (FGSV, 2017)
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NOTE: Also applies to inclined median islands with single-sided safety barriers with separate action.
Figure 14-7 Height of Temporary Steel and Precast Concrete Protective Devices Installation on Existing Surfaces
with Superelevation Rate of s ≤ 6 % (negative surface superelevation rate shown) (FGSV, 2017)
14.3.3. In-Situ Concrete Protective Devices
In-situ concrete protective devices shall be installed vertically.
The installation height of in-situ concrete protective devices in the case of negative unpaved
shoulder superelavation rates (s ≤ 6 %), distanced up to 0.6 m from the highway surface edge
line shall be referenced to the highway pavement edge line. In this case, the height of the
protective devices is adjusted (Figure 14-8). At greater distances from the reference line the
height of the safety device shall have no reference surface on the road surface but the ground
directly in front of the device (Figure 14-9).
Figure 14-8 Height of In-Situ Concrete Protective Devices, Downgraded Unpaved Shoulder (a ≤ 0.6 m) (FGSV,
2017)
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Figure 14-9 Height of In-Situ Concrete Protective Devices, Downgraded Unpaved Shoulder (a > 0.6 m) (FGSV,
2017)
In cases of positive unpaved shoulder superelavation rates (s ≤ 6 %), the height of the
protective device directly in front of it (hE=hp) is considered (Figure 14-10).
In-situ concrete protective devices can be installed on surfaces with a positive or negative
grade from 6 - 12 %. In such cases, after consultation with the Managing Authority, an
adjustment of the support surface at the area of the protective devices’ working width shall be
required in order to create an area with a maximum grade value of 6 %.
Figure 14-10 Height of In-Situ Concrete Protective Devices, Upgraded Unpaved Shoulder (FGSV, 2017)
14.4. Inadequate Unpaved Shoulder
In rural highways with inadequate unpaved shoulder support width, the protective device can
be installed on the slope of the embankment. The typical case of installation and measurement
of the protective device’s installation height is shown in Figure 14-11.
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Figure 14-11 Height of Protective Device, on Embankment Slope with an Inadequate Unpaved Shoulder Width
(ASTRA, 2013)
Where the distance of the protective device from the edge line of the highway deck is less
than 0.10 m, the installation height of the protective device shall be measured from the surface
of the slope (reference level) directly in front of the protective device. In a different case from
the surface of the paved edge line (extension of poles).
In a similar case where the slope of the embankment is 1:4 - 1:2 (rise over run) the installation
of the protective device and the measurement of its installation height may also take place on
the basis of Figure 14-12. The height of the protective device in this case is measured by
reference to slope 1:3.
Figure 14-12 Installation of Protective Device, on Embankment with Slope 1:2 - 1:4, with Inadequate Unpaved
Shoulder Width (Traffikverket, 2015).
14.5. Structures with Curb Heights (≤ 0.10 m)
Protective devices which have undergone impact tests mounted on structures with curbed
areas of 4 % grade and typical curb height 0.075 m may be installed on structures with curbed
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areas of up to 6 % grade and curb height of up to 0.10 m without adjusting the height of the
safety barrier (Figure 14-13).
Figure 14-13 Height of Protective Device (hE) on Structures (FGSV, 2017)
14.6. Structures with Curb Heights (> 0.10 m)
For cases of existing and unavoidable curbs along typical road sections (excluding intersection
and interchange areas), or special structure curbed areas (e.g. bridge sidewalks), with
height ≥ 0.10 m above the pavement edge line, the following apply:
•
Case 1-distance of protective device up to 0.25 m from the curb:
The height of the protective device shall be constructed with reference to pavement
edge line (Figure 14-14).
Figure 14-14 Height of Protective Device (hE) on Curb Heights > 0.10 m and Lateral Distance ≤ 0.25 m (FGSV,
2017)
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•
Case 2- distance of protective device greater than 0.25 m and up to 1.50 m from the
curb:
The height of the protective device shall be constructed with reference to pavement
edge line by increasing its height by half the height of the curb (Figure 14-15). A wall
-type protective device (concrete) shall not normally be adjusted, as according to its
solid construction, there is no possibility of a vehicle sliding beneath it.
Figure 14-15 Height of Protective Device (hE) on Curb Heights > 0.10 m and Lateral Distance 0.25 - 1.50 m (FGSV,
2017)
•
Case 3-distance of protective device greater than 1.50 m from the curb:
The height of the protective device shall be constructed with reference to supporting
surface immediately preceding the protective device (Figure 14-16).
Figure 14-16 Height of Protective Device (hE) on Curb Heights >0.10 m and Lateral Distance >1.50 m (FGSV, 2017)
The manufacturer's protective device installation instructions shall also be taken into account.
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At the beginning or endings of curb areas or sidewalks of structures, it may become necessary
to adjust the height of the protective device. Such a vertical elevation adjustment should be
formed at an inclination of 1:20 (rise over run) or less.
14.7. Tolerances
The protective device shall not deviate from its horizontal intended position by more than ±
0.05 m (distance from the reference line). The minimum lateral distance of 0.25 m from the
reference line shall also not deviate by the same horizontal tolerance value.
A protective device shall not deviate by more than 0.02 m for a length of 4 m from its tangent
alignment. The installation height shall also not vary by more than 0.02 m for a protective
device length of 4 m.
Even with respect to the installation tolerances of the protective device, no discontinuities and
gaps greater than 0.02 m may occur, which may result in a potential anchorage of the vehicle
sliding along.
The installation height of a protective device shall not deviate by more than ± 0.03 m from its
theoretical height.
In all cases where the height of the protective device is referenced to the unpaved shoulder
surface, the height deviation of the protective device shall not exceed ± 0.05 m from its
theoretical height.
In cases where the protective device has been subjected to an impact test with a concerted
action of a railing, the distance between the protective device and the railings shall not deviate
by more than ± 0.10 m from the corresponding distance during the impact test. If a higher
deviation value is accepted as part of a construction change/modification of the protective
device with a declaration from the accredited organization, the installation of the protective
device in its modified form is also accepted.
The protective device on structures is normally placed at a distance of 0.5 m between the front
face of the device and curb. This distance may be reduced or increased taking into account
the above-mentioned relevant height adjustment rules.
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15. In-Situ Concrete Barriers
15.1. Special Requirements
In-situ concrete barriers (ISCB) shall be manufactured in accordance with the approval
certificate or authorization for installing in-situ concrete barriers, which includes (in addition
to the performance certificate according to EN 1317) the durability certificate (lifetime) in
accordance with the certificate of constancy of performance of in-situ concrete barriers as
stated in Figure 15-1.
The steps sequence shown in Figure 15-1 should be understood as an overview presentation
of the organizational structure of the entire process. Deviation of the above steps sequence
can be allowed as a concurrent execution of specific steps, if deemed appropriate. Such a
possibility must be examined on a case-by-case basis. In practice, the actions of the
Manufacturer and the Manufacturing Unit can be implemented by the same body, provided
they meet the relevant conditions.
In-situ concrete barriers may only be installed by a specialized construction workgroup, as
specified in the relevant approval certificate.
The approval certificate for installing in-situ concrete barriers shall be presented at the time of
submission of the manufacturer's offer and at the latest before the restraint project is assigned
to a contractor.
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Figure 15-1 Flowchart of Requirements for the Certificate of Constancy of Performance of In-Situ Concrete
Barriers (BASt, 2013)
15.2. Construction Procedure
15.2.1. Materials
For the construction of the in-situ concrete barriers, at least class C30/37 XC4, XD3, XF4, WA
concrete must be used in accordance with EN 206 and the Kingdom’s Concrete Regulation,
unless the instructions for the installation of the manufacturer require a higher concrete class.
During the impact test, the concrete shall meet at least the compressive resistance
requirements as specified in SASO EN 1317.
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For the composition, construction and processing of the in-situ concrete, the standards of EN
206, EN 13670 and the Kingdom’s Concrete Regulation apply, as long as no other separate or
complementary instructions and specifications have been issued by the competent authority.
15.2.2. Installation
15.2.2.1
Personnel
The contractor must have at least one qualified technician or craftsman with a recognized
concrete technician certificate.
The driver of the concrete layering machine must be specially trained.
The connection of reinforcement by welding is only permitted to be performed by qualified
personnel with relevant welding certificate.
15.2.2.2
General implementing rules
The in-situ concrete shall be placed vertically on the inclined surface of the road (the
longitudinal grade of the seating surface is the same as that of the road). Deviations of up to
± 5 % shall be allowed.
The bearing base must be properly prepared and in such a way that the bearing surface
satisfies the respective tolerances defined by the installation instructions. The surface must be
cleaned (fragments and detached parts must be removed).
If the safety barrier is placed on the crown of the paving base or on an insufficiently compacted
bearing layer of pavement, this layer must be 0.20 m wider from the support surface of the
safety barrier in order to facilitate the loads transfer. Since the layer support is sufficiently
compacted, this width amounts to 0.10 m.
The position of the reinforcement shall be presented in drawings of the installation
instructions. Deviations during implementation must not exceed ±6mm in height. The
distances between the reinforcement must not deviate more than ±4mm. Horizontal deviation
must not be more than ± 4 mm from the intended position. In addition, it is required to
observe the required thickness of concrete covering.
The width dimensions of the concrete safety barrier must not differ by more than - 1 cm and
+ 5 cm from the theoretical width requirement.
Fresh concrete shall not be used at temperatures below + 5 °C or above + 35 °C.
15.2.2.3
Creating drainage openings
Where surface water needs to be drained, openings (holes) shall be formed on the rectangular
base of the barrier and according to the shape of its cross-section, with dimensions between
50 and 100 mm in height and 100 to 400 mm in length (minimum opening cross-section
requirement: 100 cm2 per 4 m).
Drainage openings shall be constructed in deviation of impact tests, provided that the
openings do not cause a reduction of the bearing surface and cross-sectional area of the
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barrier of more than 15 % and the longitudinal reinforcement (tensile) is not interrupted.
Concrete reinforcement covering must be ensured.
15.2.2.1.
Creation of joints in cases of continuous reinforcement protected against
corrosion
Special care and differentiation of the method should be applied, in order to meet the
temperatures of KSA.
In order to avoid unforeseeable cracks and prevent changes in length during the hardening
and contraction of concrete, the total length of the safety barrier is subdivided into individual
sections by creating contraction expansion joints (pseudo-joints) arranged perpendicular to
the longitudinal axis of the safety barrier. Pseudo-joints (Figure 15-2) are created by grooved
notches in the concrete.
Figure 15-2 Indicative Form of Contraction Expansion Joint (Pseudo-Joint) (BASt, 2013)
The notch is generated mechanically. In exceptional cases, when the lengths are small, the
notches can also be created manually.
The spacing between pseudo joints shall be 3 to 6 m. It is advisable to place the pseudo-joints
in areas of existing or planned reduction of the safety barrier’s cross-section (e.g. locations of
drainage openings).
The pseudo-joints of in-situ concrete barriers lying on rigid pavements are created at the
positions where the transverse joints of the rigid pavement exist.
The notches at the pseudo-joints are created every 2 to 3 mm at a depth of 40 to 50 mm. For
this purpose, devices with linear cut capability and no sharp cutting edges are used.
Joints created at the end of the working day (work stoppage) are formed as contraction joints
perpendicular to the surface and longitudinal axis of the concrete safety barrier. Their ending
is formed vertically. In such areas, the reinforcement shall be continued.
Cases of wide length cracks, distanced up to 500 mm from the expansion joint or between
joints, shall be restored provided that their range is greater than 0.4 mm. Cases where the
distance between a crack and a pseudo-joint is greater than 500 mm shall be restored provided
that their range is greater than 0.9 mm. The restoration can be performed by injecting epoxy
resin.
In cases of more than 3 such non-standard wide cracks per segment, the segment shall be
replaced.
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15.2.3. Control
The position of the steel placed shall be documented on each working day by means of a
photo with a readable scale and date and shall form part of the internal surveillance protocol.
15.3. Certification and Quality Control Requirements
Besides the requirements related to the certificate of constancy of performance shown in
Figure 15-1, the additional steps that are necessary for maintaining the verification validity are
shown in Figure 15-3.
Figure 15-3 Flowchart of Requirements for Maintaining the Verification Validity (BASt, 2013)
The technical assessment and verification of the certificate of constancy of performance of an
in-situ concrete barrier is performed by a recognized competent authority. The necessary
actions for the preparation of the evaluation process can be assigned by this recognized body
to another accredited organization.
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16. Installation, Assembly and Internal Control
16.1. Internal Installation Control
The contractor of the project is responsible for the internal supervision of the VRS installation.
These constitute appropriate audits to determine whether the quality properties of the VRS
components, parts or accessories, materials, mixtures of materials and means of connection as
well as the assembly and final performance of the system meet the contractual obligations of
the project.
Upon delivery of the system at the project site, a visual check shall be performed for potential
damages to the material and system parts.
If deviations from the contractual obligations are identified during this internal control, the
contractor must immediately remedy the deficiencies. If this is not possible, the competent
highway authority should be informed immediately.
For each working day and VRS component, a protocol shall be drawn up regarding the internal
supervision of the works carried out, whether it relates to repairs, replacements or new
installments in accordance with Appendix A, forms A1 to A6. The control of the anchorages
shall be carried out in accordance with the following paragraph and shall always be entered in
a register (Appendix A, form A7). For cases of in-situ concrete barriers the form shown in
Appendix A (form A8) shall always be filled in.
Anchorage on foundation bases, bridges and other structures shall be audited in accordance
with the provisions of the anchorage instructions by means of controlling the maximum torque
during the VRS assembly, utilizing a calibrated device. If the intended value assembly torque
is not reached, the task shall be regarded as a deficiency which shall be immediately restored.
The compliance of the installed VRS with the manufacturer's performance statement and its
performance certificate according to SASO EN 1317 or the certificate of performance
according to the comparative method of authorization of the infused concrete shall be always
audited.
The costs of internal supervision of the installation of a VRS shall not be charged separately.
16.2. Inspection Control
The highway competent authority shall conduct an inspection regarding the installation works
and shall perform related audits to verify whether the quality characteristics of the
components, materials and mixtures, the installation method and the relative performance of
the VRS equipment meet the contractual obligations of the contractor. The results of the
relevant audits shall be the criterion and basis for approving the VRS installation works.
The cost of this inspection control shall be covered by the highway competent authority.
The contractor should provide proof and guaranties that the installation quality, is in
accordance with the one required by the manufacturer.
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16.3. Additional Controls
Where it is considered that the result of an audit does not represent all or part of the quality
of the works, the contractor shall be entitled to require additional audits to be carried out on
specific individual operations. The locations where the relevant audits will be carried out shall
be determined jointly between the contractor and the highway competent authority.
The highway competent authority’s right to carry out additional audits at its discretion remains
inalienable.
The results of the initial and additional audits shall be decisive only for the approval,
compilation and submission of a bill for the individual operations.
The costs of the additional audits requested by the contractor shall be covered by the
contractor.
16.4. Arbitration Controls
An arbitration control is the resumption of an audit that is carried out by the contractor or the
highway competent authority for which there is a documented doubt regarding its technical
correctness.
The arbitral control shall be carried out at the request of either party by a body which is
mutually accepted and has not carried out the initial audits. The result of the arbitration control
replaces the results of the initial audits.
The costs of the arbitration control including additional related costs shall be covered by the
party against whom the outcome of the arbitration control is made.
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17. Technical Criteria and Quality Assurance
Vehicle restraint systems shall be installed in the same configuration as during the impact test
(e.g. single sided median concrete barriers, for which during the impact test there was no filling
of the island area between with soil, should be also without filling material).
Since the SASO EN 1317 impact testing has been carried out in predefined conditions
(foundation, soil type, etc.), which cannot cover all possible cases during their in-situ
implementation, it is possible that a certified VRS may not be available for the specific case. In
such cases, a certified system, presenting a similar way of installation to the actual conditions
can be selected.
Deviations from the present Guidelines must be reported officially to the competent
Contracting Authority or the Head of the Authority in terms of submitting acceptance
protocols, check sheets, etc.
Vehicle restraint systems shall be stored and transported in accordance with the
manufacturer's instructions and in accordance with the relevant standard EN ISO 1461 and EN
10346. Small galvanizing damage to the protective devices shall be restored in accordance
with EN ISO 1461.
To ensure high quality characteristics of protective devices, it is not sufficient to comply with
the SASO EN 1317 standard only, but additional requirements adapted to particular aspects
of the construction process of a highway shall be served as well (e.g. narrow side formations,
etc.). In this view, particular emphasis is placed on the provision of a protective device that
fully meets the desired road safety levels, while at the same time aspects such as availability,
quality of material and performance, factory support, repair and replacement capabilities shall
be also concurrently addressed.
For this purpose, certain technical criteria have been formulated that can be used by the
competent technical services during relevant tender notices. The fulfillment of certain criteria
by contractors of protective devices may be demonstrated by the submission of relevant
specific certificates or attestations. Alternatively, the manufacturer of a protective device may
include the specific certificates in the specifications of the protective device system made
available by him in order to facilitate the process for the Management Authority.
A key feature of the technical criteria is the attempt to establish as far as possible a continuous
and uniform protective device rather than the fragmentation of the protective device into
individual systems. Despite this effort, it is possible for some specific and limited construction
works on a certain highway to require protective devices that meet additional requirements.
In addition, compatibility aspects regarding transitions with existing or future systems shall
also be taken under consideration. This means that future projects related to protective devices
installations shall concurrently meet the technical criteria for the main systems as well as their
transitions and terminals. Special attention in this respect for the Management Services is the
provision of protective devices with exchangeable parts (modular protective devices) from
various producers, as this will achieve the rapid and economical repair or replacement of
damaged protective devices.
The following sections provide technical criteria and quality assurance aspects for the following
VRS types:
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•
•
•
•
Safety barriers.
Terminals.
Transitions.
Crash cushions.
17.1. Safety Barriers
The technical criteria for safety barriers are described in Table 17-1 and Table 17-2 . The criteria
SB1 to SB5 must be satisfied compulsorily, while the fulfillment of the criteria SB6 to SB9
depends on the specificities of VRS design process.
Table 17-1 Technical Criteria for Safety Barriers (BASt, 2019)
Certificates Submission
Requirements
SB1
Supporting documents/certifications
For certified protective devices all
relevant evidence of the proceedings
Certificate of stability of
certification are submitted (e.g. table of
performance by accredited
amendments, reports testing, product organization with the appendices
performance certification documents by
and producer’s performance
an accredited body, reports and
statement.
documents, etc.)
Based on
system
For in-situ concrete protective devices a
certificate of performance in
Performance certificates in
accordance with SASO EN 1317 and
accordance with SASO EN 1317 and Based on
Alternatively additional certificate for durability. The
durability (over 25 years) with the
system
certificates will be issued both for the
relevant annexes.
product as well as for the in-situ
construction process.
Positive impact tests against SASO EN 1317
Requirements
Supporting documents/certifications
SB2
Submission of test reports of an
accredited lab and performance
certificate issuance (stability) from an
accredited organization according to
SASO EN 1317.
Test report.
Based on
test
SB3
Submit impact video (.avi or .mpeg file)
in accordance with SASO EN 1317.
Video.
Based on
test
System and Installation Documents
Requirements
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Supporting documents/certifications
89
SB4
Submission of protective device data.
Data sheet.
Based on
system
SB5
Submitting producer’s installation
instructions with date, version #, and
aspects related to construction.
Installation Instructions.
Based on
system
Table 17-2 Technical Criteria for Safety Barriers related to Road Safety (BASt, 2019)
Road safety criteria
Requirements
Supporting documents/certifications
SB6
Reporting on whether during the
impact test in accordance with SASO
EN 1317 parts with mass >2 kg have
been detached.
Reference to the impact test
report.
Based on
system
SB7
Reporting on whether the protective
device has dangerous morphological
parts (sharp poles, projections, etc.)
Protective device’s technical
drawings.
Based on
system
SB8
Reporting on whether the protective
device has additional protective
Evidence on tests of additional
structures for motorcyclists, integrated
structures and the total system.
into the impact test and the
performance certificate.
Based on
system
SB9
Reporting on whether the impact test
was performed in conditions of
limited space, near slopes, various
obstacles (trees, signs, manholes, etc.)
and on hazardous locations in
general.
Based on
system
Reference to test reports and in
the item sheet.
Protective devices installed on structures, for safety reasons shall comply with additional
requirements. These relate to anchorage and transmitted forces aspects and are outlined in
Table 17-3.
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Table 17-3 Additional Technical Criteria for Safety Barriers regarding Structures (BASt, 2019)
Additional requirements for protective devices on structures
Requirements
Supporting documents/certifications
SBStr1
Positive impact test on similar to the
structure side formation
configuration.
Description in the report of test
control.
Based on
system
SBStr2
Force measurements during impact
test, and classification according to
containment levels L2 and L4b. For
L1 containment level the theoretical
calculations are adequate.
Recording of the measured forces
the assessment report, and
respective classification.
Based on
system
SBStr3
Protective device support in
concrete.
Listing in test control report.
Based on
system
SBStr4
SBStr5
SBStr6
SBStr7
Certificate of operational adequacy
compatible with the operation of the
Audited calculation of forces
respective movable joints
transferred and if possible listing in
(contraction - expansion) of the
the test audit report.
bridge
Disposal of appropriate vehicle
parapet off-structure with
connection via transition
Based on
system
Certificate of criteria satisfaction for
vehicle parapets off-structure and
the appropriate transitions.
Based on
system
Non-existence of detachable parts >
2 kg which will fall from the
Listing in the test control report and
structure edge lines with risk for
impact video.
third parties (for containment levels
L2 and L4b).
Based on
system
Installation instructions with
additional suggestions for
installation on structures.
Installation instructions.
Based on
system
17.2. Terminals
Terminals of protective devices shall comply with the requirements of SASO EN 1317. As the
implementation of EN 1317-4 is not yet a basis for system certification (non-harmonized
standard), the quality requirements and controls for these systems are regulated at national
level. Until the full adoption of Part 4 of standard EN 1317, the manufacturer (producer) of
protective devices has to submit attestations of the operational performance of the terminals.
The relevant requirements for terminals are set out in Table 17-4.
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Table 17-4 Technical Criteria for Terminals (BASt, 2019)
Submission of certificate for terminals
Requirements
Supporting documents/certifications
TER1
Submission of certificate regarding
operational satisfaction requirements
(essential characteristics) of terminals in
relation to the connected protective
devices.
Certificate of good operation.
Based on
system
TER2
Submission of data sheet.
Data sheet.
Based on
system
TER3
Submission of Installation manual
including description documents for
product and drawings.
Installation manual.
Based on
system
17.3. Transitions
The transition elements shall meet the requirements of SASO EN 1317. As the implementation
of EN 1317-4 is not yet harmonized, the quality requirements and controls for these systems
are regulated at national level. Until the adoption of Part 4 of standard EN 1317, the
manufacturer (producer) of transitions shall submit operational performance statements. The
relevant requirements for transitions are set out in Table 17-5.
Table 17-5 Technical Criteria for Transitions (BASt, 2019)
Submission of certificate for transitions
Requirements
92
Supporting documents/certifications
TR1
Submission of a certificate of
satisfaction regarding operational
requirements of transitions.
Certificate of good operation.
Based on
system
TR2
Submission of data sheet.
Data sheet.
Based on
system
TR3
Submission of Installation manual
including description documents for
product and drawings.
Installation manual.
Based on
system
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17.4. Crash Cushions
Crash cushions must bear a CE mark. or equivalent officially accepted by SASO. The
requirements are set out in Table 17-6.
Table 17-6 Technical Criteria for Crash Cushions (BASt, 2019)
Submission of certificate
Requirements
CC1
All supporting documents of the
certification process (certification
reports, modifications, etc.) shall be
submitted.
In these documents the crash
cushion type must be explicitly
mentioned "return" (Type R).
Supporting documents/certifications
•
•
Certificate of performance
with annexes.
Type of crash cushion:
“Return” if not mentioned in
the certificate of
performance.
Based on
system
Positive impact test check in accordance with SASO EN 1317
Requirements
Supporting documents/certifications
CC2
Submission of control test reports
of a notified body in accordance
with the with standard SASO EN
1317.
Test report.
Based on
system
CC3
Submit impact video (.avi or .mpeg
file) in accordance with SASO EN
1317.
Video.
Based on
system
System documents and Installation
Requirements
Supporting documents/certifications
CC4
Submission of data sheet.
Data sheet.
Based on
system
CC5
Submission of Installation manual
including connection aspects to
the proceeding protective device.
Installation manual.
Based on
system
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18. Passive Safety Poles and Posts
18.1. Standards
Passive safety poles and posts offer a lower risk of personal injury when struck by a vehicle.
Poles and posts are by default placed adjacent to the roadway in order to serve their intended
functions.
The use of such systems has become a cornerstone of the forgiving roadside concept over the
last 50 years.
Worldwide, two approaches prevail; namely, the US MASH and the European EN 12767. The
following sections provide a brief outline of both contexts.
18.1.1. US MASH
The US MASH concept describes passive safety poles and posts as “breakaway devices”
referring to crash-tested devices that separate, fracture or yield upon impact. US MASH criteria
require the specification of breakaway structures and bases meeting rigorous impact testing
to mitigate the potential severity of crashes, providing a safer outcome in the event of a
collision.
The release mechanism may be a slip plane, plastic hinge, fracture element, or a combination
of these.
18.1.2. EN 12767
EN 12767 is a European Norm which provides passive safety solutions by adopting a protocol
according to which crash testing of vehicles with objects or support structures for road
equipment are performed in a consistent way.
The standard specifies performance requirements and defines levels in terms of passive safety
to reduce the severity of injury to the occupant(s) or other traffic and road users in the event
of an accident with an object or support structure for road equipment. The harmonization of
the European standard results in the national EN 12767 standard.
The present chapter is structured based on the EN 12767 approach.
18.2. Test Conditions and Performance Classes
18.2.1. Testing of Passive Safety Poles and Posts and Types
The method for performing crash tests is described in the EN 12767 in terms of:
•
•
•
Impact angle.
Impact point.
Impact speed.
In general poles and posts follow certain EN standards. Their basic types are as follows:
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•
•
•
•
•
•
Lighting poles, which shall be tested with the longest and heaviest single arm bracket,
and luminaire of the greatest mass related to the bracket length, for which the column
is designed.
Sign supports, which shall be tested with the largest area of symmetrically mounted
sign plate for which that height of support is designed.
Signal supports, which shall be tested with the heaviest signal head(s).
Utility poles, which shall be tested with the heaviest intended load.
Multipurpose support structures which include structures designed to be used in more
than one configuration, such as lighting columns, sign supports, traffic signal supports,
etc.
Other support structures (e.g. advertisement installations, gantries, camera supports,
etc.), which shall be tested with the heaviest intended load.
The crash tests comprise of a standard light-weight 900 kg passenger car.
For ensuring better reliability of test results the tests shall be performed by an accredited test
laboratory.
18.2.2. Performance Classes
The performance class of each tested support structure shall be expressed as a combination
of the following parameters:
•
•
•
•
•
•
•
Impact speed.
Energy absorption class.
Occupant safety level.
Backfill type.
Collapse mode.
Direction class.
Risk of roof indentation.
18.2.2.1
Impact speed
Impact speeds testing of 100 km/h, 70 km/h and 50 km/h are carried out that correspond to
high-speed impact tests and road environments such as freeways, rural areas and urban areas
respectively. For every high-speed test a low-speed test at 35 km/h must also take place.
18.2.2.2
Energy absorption class
According to the degree of energy absorption, there are 3 classes; namely, high energy (HE),
low energy (LE) and non-energy (NE) with the following characteristics:
•
•
•
HE support structures decelerate a vehicle the most but at the same time usually cause
the most damage to the vehicle since the energy of the impact is highly adsorbed,
which in turn, may result in secondary danger for the occupants.
LE support structures usually bend slightly and then either break off or are knocked
down, with a certain amount of energy absorption (vehicle speed reduced).
NE support structures enable the vehicle to continue at the same or slightly reduced
speed after a crash by breaking or extirpating the support structure, which on one hand
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reduces the chance of injury to the occupant(s) but increases the risk of a secondary
accident on the other.
The energy absorption classification as a function of vehicle impact speed is shown in
Table 18-1.
Table 18-1 Energy Absorption Classification as a Function of Vehicle Impact Speed (EN 12767)
Impact speed (km/h)
50
70
Energy Absorption Class
18.2.2.3
100
Exit Speed (km/h): Vexit
HE
Vexit = 0
0 ≤ Vexit ≤ 5
0 ≤ Vexit ≤ 50
LE
0 < Vexit ≤ 5
5 < Vexit ≤ 30
50 < Vexit ≤ 70
NE
5 < Vexit ≤ 50
30 < Vexit ≤ 70
70 < Vexit ≤ 100
Occupant safety level
Occupant safety is expressed as a function of the ASI (Acceleration Severity Index) and THIV
(Theoretical Head Impact Velocity) values of the mandatory high speed and low speed tests.
The levels A, B, C, D and E indicate the level of occupant safety (Table 18-2).
The best occupant safety is reached by level A. Requirements, besides ASI and THIV values, for
level A are as follows:
•
•
Vehicle remains upright after the impact.
Difference between the measured impact speed and exit speed shall not be greater
than 3 km/h.
Table 18-2 Occupant Safety Levels as a Function of ASI and THIV Values (EN 12767)
Speeds
Energy
Absorption
Class
Occupant
Safety Level
Low Speed Test
35 km/h
High Speed Test
50 km/h, 70 km/h, 100 km/h
Maximum Values
Maximum Values
ASI
THIV (km/h)
ASI
THIV (km/h)
HE / LE/ NE
E
1.0
27
1.4
44
HE / LE/ NE
D
1.0
27
1.2
33
HE / LE/ NE
C
1.0
27
1.0
27
HE / LE/ NE
B
0.6
11
0.6
11
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Speeds
Energy
Absorption
Class
Occupant
Safety Level
HE / LE/ NE
18.2.2.4
A
Low Speed Test
35 km/h
High Speed Test
50 km/h, 70 km/h, 100 km/h
Maximum Values
Maximum Values
ASI
THIV (km/h)
ASI
No
Requirements
No
Requirements
THIV (km/h)
No ASI and THIV
Measurements
Backfill type
The manufacturer shall select the type(s) of backfill to be used in the type tests from those
given in Table 18-3.
Table 18-3 Backfill Types (EN 12767)
Backfill Type
Name
S
Standard Aggregates
X
Special
R
Rigid
Backfill type S identifies the use of backfill material which is a standardized soil of a certain
composition and density as defined in EN 12767. Type S backfill material differs in accordance
with existing groundwater level.
Backfill type R identifies the use of a flat continuous rigid surface (such as asphalt and/or
concrete) of a sufficient thickness to provide anchoring of the tested item without being
displaced, as defined in EN 12767.
All types of foundations that do not fall under backfill type S and R are classified as type X.
Such examples are saturated soil, clay or gravel. Since backfill type X differs per manufacturer,
it is not comparable to the respective types S and R.
In general, the backfill type has a great impact on the performance of a support structure and
must perform under the actual situation in which it is placed. In order to deal with deviations
in the soil type between practice and test conditions, the impact of soil variances can be
minimized by installing the support structure into a larger diameter plastic tube. However,
such a foundation needs to be tested by an accredited test laboratory in order to prove that
there are no deviations in the performance of the support structure.
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18.2.2.5
Collapse mode
Support structures shall be classified according to their collapse mode, which indicates the
way they behave in the event of a collision. The following collapse modes apply: SE (separation,
where the support structure detaches from the ground or its foundation) and NS (no support
separation, where the support structure does not detach from the ground or its foundation).
18.2.2.6
Direction class
Support structures shall also be classified according to their direction class. The following three
direction classes apply:
•
•
•
Single directional (SD) structures can only be safely hit from one direction assuming a
20 º impact angle.
Bi directional (BD) structures which also perform for traffic coming from the opposite
direction (20 º and 160 º).
Multi directional (MD) structures which are not sensitive to impact angle and can be
hit from various driving directions.
18.2.2.7
Risk of roof indentation
A collision with a structure can result in the formation of a dent in the roof of the vehicle, with
risk for the occupant(s). EN 12767 introduces the risk of vehicle roof indentation as sensitive
to dents (class 1) and not sensitive to dents (class 0).
Support structures shall be classified for the risk of roof indentation in accordance with
individual test measurements specified in EN 12767. In general, the breakpoint of vehicle roof
indentation is set to 102 mm as follows:
•
•
Class 0: roof deformation < 102 mm.
Class 1: roof deformation ≥ 102 mm.
18.2.3. Specification Test Conditions and Performances
The notification example shown in Figure 18-1 is used to indicate the performance classes.
NOTE: Certain performance properties may be of no interest or impact, or multiple choices are allowed. In that
case the specific property of the support structure performance can be of “no requirement” (NR).
Figure 18-1 Passive Safety Structures Performance Classes (EN 12767)
18.3. Type Selection Criteria
The positioning of a support structures within the highway’s critical distance / clear zone may
require protection by installing VRS. This depends on:
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•
•
Whether the support structure is regarded as an obstacle.
What is behind the support structure.
However, the installation of passive safety poles or posts may not require the coexistence of
VRS. For example, support structures positioned on highway median areas, need to be
protected from potential vehicle collision (danger on the opposing traffic direction) and
therefore the installation of VRS is necessary. On the other hand on highway edge line areas,
the danger behind a support structure is less, and consequently, the installation of a passive
safety support structure is possible.
For cases where the installation of passive safety support structures is an option, the risks for
the vehicle occupants but also third parties must be taken into account. In such cases,
depending on the posted speed, the presence of obstacles behind, or other highway users,
there are certain options.
18.3.1. NE Type Support Structures
Non-energy (NE) support structures (Figure 18-2) have a very good performance for cases
where the background is vacant in terms of obstacles (e.g. pedestrians, cyclists, trees, etc.). The
most favorable NE class in terms of occupant safety level can be achieved by fitting the support
structure with an additional shear off system. In addition, an equivalent backfill to the
respective testing of the support structure must be foreseen.
Figure 18-2 Non-Energy Absorbing Support Structures (Willems, 2015)
18.3.2. LE Type Support Structures
Low energy (NE) support structures (Figure 18-3) in general are cost effective and do not
require extra engineered features. A potential solution is the LE C occupant safety level.
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Figure 18-3 Low Energy Absorbing Support Structures (Willems, 2015)
18.3.3. HE Type Poles
High energy (HE) support structures (Figure 18-4) may have or have not a vehicle exit speed.
Such support structures are used in cases where there are obstacles behind, without the
necessity of VRS. The occupant safety level must be as high as possible.
Figure 18-4 High Energy Absorbing Support Structures (Willems, 2015)
18.3.4. Performance Class Recommendations
The installation of passive safety support structures, instead of VRS should follow the benefitcost analysis that has to be conducted, for every section of the road side that needs to provide
protection to the nearside hazards.
Table 18-4 shows in terms of priority the performance class recommendations for passive
safety support structures.
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Table 18-4 Performance Class Recommendations for Passive Safety Support Structures (BS EN 12767)
Type of Support Structure
Situation
Location
Unpaved
shoulders of
Motorways,
Divided and
Undivided
Highways
Highways and
Streets with
Posted Speed >
60 km/h
With Significant
Volume of NonMotorized Users
at the Times
when Impact
Events Occur
Where Major Risk
of Items Falling
on Other
Highways Below
Lighting Poles
Sign or Signal
Support
Other
100-NE-NR-NRNR-MD-0
100-NE-NR-NRNR-MD-0
100-NE-A
[A] 100-HE-NRNR-NR-MD-0
100-HE-NR-NRNR-MD-0
[B] 100-LE-NRNR-NR-MD-0
100-NE-A
[C] 100-NE-NRNR-NR-MD-0
[A] 100-HE-NRNR-NR-MD-0
100-HE-NR-NRNR-MD-0
[B] 100-LE-NRNR-NR-MD-0
[C] 100-NE-NRNR-NR-MD-0
100-NE-A
or
70-NE-A
[A] 70-HE-NRNR-NR-MD-0
Highways and
Streets with
Posted Speed
≤ 60 km/h
All locations
[B] 100-HE-NRNR-NR-MD-0
[A] 70-HE-NRNR-NR-MD-0
[C] 70-LE-NR-NRNR-MD-0
[B] 100-HE-NRNR-NR-MD-0
100-NE-A
[D] 100-LE-NRNR-NR-MD-0
[C] 70-LE-NR-NRNR-MD-0
70-NE-A
[E] 70-NE-NRNR-NR-MD-0
[D] 100-LE-NRNR-NR-MD-0
or
[F] 100-NE-NRNR-NR-MD-0
NOTE: Classifications ([A] – [F]) listed in order of priority. Direction class MD is the most preferable for all cases,
followed by clad BD and SD.
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19. Special Solutions at Highway Intersection
Areas
19.1. General
At highway intersection areas (including access routes and/or traffic connections), curved
(rounded) safety barriers constitute a particular case. Until now, no particular requirements
were laid down for curved safety barriers, considering that the impact tests on tangent
segments based on SASO EN 1317 were sufficient to ensure their operability and performance
on curved sections also. Nevertheless, this concept is regarded as insufficient.
This type of curved safety barriers sections shall be treated as special solutions at highway
intersections (SSHIA-Special Solution at Highway Intersections). The following sections outline
the technical conditions and requirements for improving the performance of safety barriers
and, hence, road safety in general, on such curved sections.
The RGA shall take the decision, to consider the use or not of certified VRS in these situations,
considering the benefit-cost analysis that has to be conducted. The acceptance of not certified
VRS should at least, be accompanied by a simulation testing of the digital model or something
similar.
19.2. Impact Tests
19.2.1. General
Curved safety barriers with small radii, similar to the ones that apply between pavement edge
lines at intersections areas, must not become obstacles on the one hand (hazardous locations),
while on the other, must be capable of undertaking the developed longitudinal forces when
these are connected to tangent sections.
Due to their special formation, SSHIAs cannot be classified exclusively into a specific safety
barrier type. SSHIAs comprise of a combination of elements of different safety barriers types
in such a way that it is not yet possible to accurately determine the inclusion of SSHIAs in a
specific impact test type, as defined in SASO EN 1317. It is, therefore, not yet possible to verify
the performance of the essential characteristics of the SSHIAs with respect to SASO EN 1317.
The following paragraphs will describe the terms and conditions for the performance of the
appropriate impact tests on the SSHIAs, as well as the criteria regarding their installation. The
terms, conditions and acceptance criteria of the SSHIAs are based on the SASO EN 1317
standard.
The aim of this approach is to describe the most unfavorable conditions for the
implementation of the SSHIAs, in order to ensure acceptable implementation of the SSHIAs in
similar but less critical situations.
The beginning and ending of a SSHIA is determined at the actual beginning and ending area
(Figure 19-1), or where an installed safety barrier fully conforms to SASO EN 1317
requirements. The length L of the SSHIA shall include the total length of the particular
configuration, where length B shall correspond to the pure curved part of the rounded
structure (Figure 19-1).
102
SHC 102
304
Figure 19-1 Overview of a Special Solutions at Highway Intersection Areas Requirement (BASt, 2020b)
The length of the safety barrier connected to a SSHIA shall have at least 1/3 of its minimum
required length (test length).
The impact test conditions shall be provided for all tests with the same radius of curvature,
intersection angle of 90 ° and the formation of a standard slope (with rise over run) 1:1.5.
Typical values of radii of curvature for the rounding of a SSHIA range between 2.0 and 7.5 m.
In order to ensure the operability of a SSHIA during impact, the SSHIA shall be subject to the
impact tests based on SASO EN 1317 and the additional criteria outlined in Section 19.2.2. In
addition, attention shall be paid to the following requirements:
•
•
•
The physical impact tests in accordance with SASO EN 1317 shall be performed by an
accredited test laboratory in accordance with SASO EN 1317.
The impact test on a SSHIA shall apply only to the safety barrier connected to the
SSHIA. The assessment of an alteration, regarding the spacing of the supporting poles
of an otherwise identical protective device, shall be carried out by an accredited body
in terms of issuing a certificate of performance.
The impact tests and their results are described in a relevant test document (technical
report).
19.2.2. Impact Test Criteria
In order to reflect actual- to the maximum extent possible- impact conditions on a SSHIA,
impact tests with various vehicle trajectories are defined (Figure 19-2). These tests allow a
relevant producer declaration to be issued in accordance with SASO EN 1317.
SHC 304
103
Figure 19-2 Vehicle Trajectories during Impact Tests on a SSHIA (BASt, 2020b)
The critical point of impact for all three test cases depends on the construction of the SSHIA
and is determined by the accredited body issuing the certificate of performance of the barrier
in order to comply within the limits of a specific area. The impact angles shall refer to the
tangent to the SSHIA at the critical point.
19.2.2.1 SSHIA test 1
The following parameters result from the adoption of the test conditions TT 4.2.80 or TC 4.2.80
and TC 1.2.80 of SASO EN 1317-3 and the non-harmonized SASO EN 1317-4:
•
•
•
•
•
104
Impact angle: 55 o (corresponding to a diversion angle of approximately 15 o).
Mass of the impact vehicle (test): 1,300 kg.
Impact speed: 80 km/h.
Critical impact point between 1/3 B and between 1/3 L and 2/3 L of the SSHIA.
Reference axis for the critical impact point: longitudinal symmetry axis of vehicle.
SHC 104
304
19.2.2.2 SSHIA test 2
This test is oriented towards the standard impact tests for vehicle restraint systems on typical
(tangent) highway safety barrier devices. The following parameters are derived from the
adoption of the impact tests of type TB11 according to SASO EN 1317-2:
•
•
•
•
•
Impact angle: 40 o (corresponding to a diversion angle of approximately 20 o).
Mass of the impact vehicle (test): 900 kg.
Impact speed: 100 km/h.
Critical impact point between 1/3 B and between 1/3 L of the SSHIA.
Reference axis for the critical impact point: longitudinal symmetry axis of vehicle.
19.2.2.3 SSHIA test 2
This test is oriented towards the standard impact tests for vehicle restraint systems on typical
(tangent) highway safety barrier devices. The following parameters result from the adoption
of individual TB 32 tests according SASO EN 1317-2. The impact speed shall correspond to
that of crash cushions and transitions according to SASO EN 1317-3 and the non-harmonized
SASO EN 1317-4:
•
•
•
•
•
Impact angle: 160 o.
Mass of the impact vehicle (test): 1,500 kg.
Impact speed: 80 km/h.
Critical impact point starting area SSHIA.
Reference axis for the critical impact point: longitudinal symmetry axis of vehicle.
19.2.3. Collection of Impact Test Results
In order to assess the performance and behavior of the barrier during the impact of a vehicle,
the following parameters and characteristics of the SSHIA shall be collected and recorded:
•
•
•
•
•
ASI and THIV.
Deformation (dynamic deflection and working width) with reference to the tangent of
the original front face of the barrier.
Mass and position of the barrier’s detached parts with a mass greater than 2.0 kg.
Vehicle trajectory within the vehicle’s recovery area and its speed after impact, as well
as its speed when it exits the recovery area (recovery area as defined in Figure 19-3).
Photos and video recordings (Figure 19-4).
SHC 304
105
Figure 19-3 Recovery Area for the Descriprion of Vehicle Trajectory (BASt, 2020b)
106
SHC 106
304
Figure 19-4 Locations of Cameras and Video Recording Devices during Impact Tests (BASt, 2020b)
19.2.4. Contents of Impact Technical Report
The Technical Report shall include:
•
•
•
Description of the tests, photographic material and video recordings of the impact
tests as referred to in SASO EN 1317.
Certificate issued by the testing laboratory stating that the tested safety barrier and its
connected ones were in conformity with the technical drawings submitted and that it’s
installation on the test site was carried out in accordance with the instructions of the
manufacturer's installation manual.
Certificate issued by the testing laboratory stating that all components and parts of the
tested barrier were in full conformity with the installation manual and the relevant
drawings with respect to the requirements of the materials and the joints and their
dimensions.
SHC 304
107
19.2.5. Impact Test Evaluation Criteria
The following criteria shall be met for an impact test to be considered positive:
•
•
•
•
•
•
The ASI and THIV control values shown in Table 19-1 must not be exceeded.
The test vehicle shall not perform yaw turn or rollover.
The test vehicle shall not slide below the safety barrier.
No fragments of the SSHIA shall enter the interior of the vehicle.
The test vehicle shall not penetrate the SSHIA and pass over the safety barrier in
accordance with the requirements of SASO EN 1317-2.
During the impact test, the main longitudinal components of the SSHIA shall not be
allowed to separate.
Table 19-1 Characteristic Values of Impact Severity for SSHIA Test 1 – Test 3 (BaST, 2020b)
Impact Severity
ASI and THIV Values
A
ASI ≤ 1.0
B
ASI ≤ 1.4
THIV ≤ 44 km/h (SSHIA Test 1 and Test 2)
THIV ≤ 33 km/h (SSHIA Test 3)
THIV ≤ 44 km/h (SSHIA Test 1 and Test 2)
THIV ≤ 33 km/h (SSHIA Test 3)
19.2.6. Product Requirements Document
In order to ensure the correct use and installation of a SSHIA, the following documents must
be available:
•
•
•
•
Documentation of impact tests.
Installation instructions in the form of assembly instructions or as a supplement to the
installation instructions of attached safety barrier. The installation instructions shall also
provide instructions on how to deal with deviations from the impact test conditions
(e.g. intersection angle different from 90 °). Acceptance of SSHIA performance in
conditions other than those of the impact tests can be achieved either by additional
physical impact tests or by reliable impact simulations according to EN 16303.
Data sheet containing the essential construction characteristics and performance of the
SSHIA and a general drawing.
Producer's declaration that the operability of the safety barriers adjacent to the SSHIA
shall not be adversely affected.
19.2.7. Production Control
SSHIAs and their components are manufactured at the production facilities of the producer
for which valid certificates of continuous quality control and annual inspection by an
accredited body are available.
108
SHC 108
304
References
AASHTO (2011) Roadside Design Guide. 4th Edition, American Association of State Highway
and Transportation Officials, USA.
AASHTO (2016) Manual for Assessing Safety Hardware. American Association of State Highway
and Transportation Officials, USA.
ASTRA 11005 (2013) Richtlinie, Fahrzeugrückhaltesysteme, Teil B: Detailprojektierung und
Bauausführung. (Guideline Passive Safety Systems, Part B: Final Design and Construction). Bern,
Switzerland.
AUSTROADS (2018) Towards Safe System Infrastructure: A Compendium of Current Knowledge.
Sydney, Australia.
BASt (2013) Anforderungen an den Nachweis der Leistungsfähigkeit von Betonschutzwänden in
Ortbetonbauweise-Vergleichsverfahren BSW Ortbeton (VGVS BSW O). (Federal Highway
Research Institute. Requirements for the Verification of the Performance of In-Situ Concrete
Barriers, Comparison Method). Bundesanstalt für Straßenwesen, Köln, Germany.
BaSt (2019) Technische Kriterien für den Einsatz von Fahrzeugrückhaltesystemen in Deutschland,
Bergisch Gladbach. (Federal Highway Research Institute. Technical Criteria for the Use of
Vehicle Restraint Systems in Germany). Bundesanstalt für Straßenwesen, Köln, Germany.
BASt (2020a) Einsatzempfehlungen für Fahrzeug-Rückhaltesysteme. Version 06 (Federal
Highway Research Institute. Recommendations for Use Vehicle Restraint Systems, Version 06),
Köln, Bundesanstalt für Straßenwesen, Köln, Germany.
BASt (2020b) Sonderlösungen von Schutzeinrichtungen in Einmündungsbereichen. Version 04,
(Federal Highway Research Institute. Special Solutions of Protective Devices at Intersection
Areas, Version 04). Bundesanstalt für Straßenwesen, Köln, Germany.
BS EN 12767 (2019). British National Annex. Passive Safety of Support Structures for Road
Equipment. Requirements and Test Methods. United Kingdom.
ERF (2018) Improving Infrastructure Safety for Powered Two-Wheelers. European Road
Federation.
ERF (2019) An Overview of EN 1317. European Road Federation https://erf.be/en1317/#1553103269134-fa341700-a4a5 (accessed June 2022).
FGSV (1997) Technische Lieferbedingungen für Transportable Schutzeinrichtungen,
Transportable Schutzeinrichtungen. Forschungsgesellschaft für Straßen und Verkehrswesen,
Köln, Germany. (Research Society for Roads and Transport, Portable Protective Devices.
Technical Delivery Conditions for Transportable Protective Devices).
FGSV (1997) Zusätzliche Technische Vertragsbedingungen und Richtlinien für
Sicherungsarbeiten an Arbeitsstellen an Straßen. Forschungsgesellschaft für Straßen und
Verkehrswesen ZTV FRS, Köln, Germany. (Research Society for Roads and Transport, Additional
Technical Contractual Conditions and Guidelines for Securing Work at Road Work Sites).
FGSV (2009) Richtlinien für passiven Schutz an Straßen durch Fahrzeugrückhaltsysteme (RPS).
Forschungsgesellschaft für Straßen- und Verkehrswesen, Köln, Germany. (Research Society for
Roads and Transport, Guidelines for Passive Protection on Roads by Vehicle Restraint Systems).
SHC 304
109
FGSV (2017) Zusatzliche Technische Vertragsbedingungen und Richtlinien Fur Fahrzeug
Ruckhaltesysteme. Forschungsgesellschaft für Straßen und Verkehrswesen ZTV FRS, Köln,
Germany. (Research Society for Roads and Transport, Additional Technical Contract Terms and
Guidelines for Vehicle Restraint Systems).
Hydro – Pole Products (2019) Passive Safe Light Poles and Support Structures.
Trafikverket 2015:086 (2015) Krav för Vägars och Gators Utformning, Borlänge. (Traffic Works,
Requirements for the Design of Highways and Streets). Swedish Transport Administration,
Borlänge, Sweden.
TRB (2012) Roadside Safety Design and Devices. Transportation Research Circular E-C172.
Transportation Research Board, USA.
TRB (2015) Roadside Safety Design and Devices. Transportation Research Circular E-C215,
Transportation Research Board, USA.
VicRoads, Moon, W., P. Mihailidis (2013) Outcome Based Management of Roadside Hazards.
Australasian College of Road Safety Conference – “A Safe System: The Road Safety Discussion”
Adelaide, Australia.
Willems C. (2015) Creating Forgiving Roadsides by Using Passive Safe Equipment. Zippole Safety
Product, CE Marked for EN 12767.
110
SHC 110
304
Appendix A - Installation,
Internal Control
Assembly
and
A.1. Safety Barriers
Table A-1 Installation, Assembly and Internal Control Form for Safety Barriers (BASt, 2019; BASt, 2020a; FGSV,
2017; all adapted)
1
Awarding Body
2
Contractor
3
Contract / Repair Contract /
Date
4
Location (Chainage of Control
Area)
5
Assembly Technician
6
Members/Partners
Installed Safety Barrier Type
7
□, Shipping & Assembly □, Assembly/Repair □
Type of Works
Shipping
8
Weather Conditions
Dry □, Rain □, Temperature
9
Suitability, Selection and Installation of Safety Barriers
a
Certification of safety barrier with performance in effect
b
Installation manual
c
Installation in accordance with manual
d
Existence of CE certification
10
Installation of Safety Barrier
a
Joints overlapping towards the traffic direction
b
Supporting poles closed towards the traffic direction
SHC 304
o
C
Y/N
Y/N
111
c
Appropriate distance between supporting poles
d
Appropriate installation height
11
Bolts
a
Standing base and bolts fitted
b
Bolts in accordance with the instruction manual
c
Tightening torque appropriate
12
Supporting Poles / Installation on Structures
a
Supporting poles abridged (if yes approval from competent authority required)
b
Old openings for supporting poles compacted
c
Anchorage shifted correctly and tensile test performed
d
Contraction-expansion joints in accordance with installation manual
13
Subsequent On-Site Processing (e.g. adjustment parts)
Y/N
Y/N
Y/N
Minimum length of 750 mm for adjustment parts respected
Coating of joints at least 300 mm
Distance of the external openings 40 mm from the end of the safety plane
Diameter of openings respected
14
Alignment (various aspects)
a
Safety barrier aligned in terms of height
b
Safety barrier aligned in plan view
c
Distance from highway edge line respected
d
Working width and vehicle intrusion clear of obstacles
Y/N
Remarks
Name and signature of Contractor
15
Name and signature of Assembly Technician in Charge
Name and signature of Manufacturer or Legal Representative
112
SHC 112
304
Place / Date
A.2. Precast Concrete Safety Barriers
Table A-2 Installation, Assembly and Internal Control Form for Precast Concrete Safety Barriers (BASt, 2019; BASt,
2020a; FGSV, 2017; all adapted)
1
Awarding Body
2
Contractor
3
Contract / Repair Contract /
Date
4
Location (Chainage of Control
Area)
5
Assembly Technician
6
Members/Partners
Installed Safety Barrier Type
7
□, Shipping & Assembly □, Assembly/Repair □
Type of Works
Shipping
8
Weather Conditions
Dry □, Rain □, Temperature
9
Suitability, Selection and Installation of Safety Barriers
a
Certification of safety barrier with performance in effect
b
Installation manual
c
Installation in accordance with manual
d
Existence of CE certification
e
Working width and vehicle intrusion clear of obstacles
10
Assembly of Safety Barrier
a
Standing base in accordance with installation manual
b
Superelevation rate ≤ 6 %
SHC 304
o
C
Y/N
Y/N
113
c
Accessibility of connection elements
d
Safety barrier aligned in terms of height
e
Safety barrier aligned in plan view
11
Assembly of Safety Barrier (additional structure requirements)
a
Adjustment of safety barrier to the inclination of the curbs / unpaved shoulder
b
Anchorage in accordance with instruction manual
c
Contraction-expansion joints in accordance with installation manual
Y/N
Remarks
Name and signature of Contractor
12
Name and signature of Assembly Technician in Charge
Name and signature of Manufacturer or Legal Representative
Place / Date
A.3. In-Situ Concrete Safety Barriers
Table A-3 Installation, Assembly and Internal Control Form for In-Situ Concrete Safety Barriers (BASt, 2019; BASt,
2020a; FGSV, 2017; all adapted)
1
Awarding Body
2
Contractor
3
Contract / Repair Contract /
Date
4
Location (Chainage of Control
Area)
5
Assembly Technician
6
Members/Partners
114
SHC 114
304
Installed Safety Barrier Type
7
□, Shipping & Assembly □, Assembly/Repair □
Type of Works
Shipping
8
Weather Conditions
Dry □, Rain □, Temperature
9
Suitability, Selection and Installation of Safety Barriers
a
Certification of safety barrier with performance in effect
b
Installation instructions
c
Installation in accordance with manual
d
Existence of CE certification and durability certificate (lifetime)
e
Working width and vehicle intrusion clear of obstacles
10
Concrete Monitoring
a
Type of Concrete according to the suitability specifications of the competent authority
b
Internal audit implementation and related protocol
c
Concrete cube testing
d
Audit performed by a third body
11
Staff Qualifications
a
Certified welder name
b
Machine operator name
12
Installation Control
a
Surface area in accordance with installation manual
b
Correct mounting of reinforcement including welds
c
Correct operation of a metal-forming machine (waterproofing/automation)
d
Photographic documentation of the reinforcement arrangement
e
Continuous control of the tolerances/reinforcement position, and fill in “Tolerances
Layout” form
f
Fill in of concrete diary
13
Processing and Special Measures
SHC 304
o
C
Y/N
Y/N
Y/N
Y/N
Y/N
115
Surface smooth
Required materials applied?
Were specific measures taken due to high/low temperatures?
14
Joints
a
Timely joint cutting
b
Joints coincide with the notches on the foundation
c
Joints at the end of the working day vertical and with rough surface
Y/N
Remarks
Name and signature of Contractor
15
Name and signature of Assembly Technician in Charge
Name and signature of Manufacturer or Legal Representative
Place / Date
A.4. Crash Cushions
Table A-4 Installation, Assembly and Internal Control Form for Crash Cushions (BASt, 2019; BASt, 2020a; FGSV,
2017; all adapted)
1
Awarding Body
2
Contractor
3
Contract / Repair Contract /
Date
4
Location (Chainage of Control
Area)
5
Assembly Technician
6
Members/Partners
7
Installed System Type
116
SHC 116
304
Type of Works
Shipping □, Shipping & Assembly □, Assembly/Repair □
8
Weather Conditions
Dry □, Rain □, Temperature
9
Hardware Procurement/Testing
a
Completeness
b
Damage from transport
c
Compliance with the design and drawings
d
Surface area in accordance with the installation manual
10
System Eligibility, Selection and Placement Control
a
Certification of system with performance in effect
b
Installation instructions
c
Installation in accordance with manual
d
Installation drawings
e
Follow assembly instructions
f
Existence of CE certification
11
System Assembly/Control
a
Parts and accessories completeness
b
Position of foundation
c
Anchorage assembled correctly and tensile test performed
d
System positioned and assembled correctly
e
Wire-rope position checked
f
System aligned in terms of height
g
Distance from highway edge line respected
12
Connections
a
Concrete safety barrier
b
Safety barrier (steel)
13
Miscellaneous
a
Minimum length of 750 mm for adjustment parts respected
SHC 304
o
C
Y/N
Y/N
Y/N
Y/N
Y/N
117
b
Compliance with traffic safety measures
c
Remaining parts on the foundation and around the system removed
Remarks
Name and signature of Contractor
14
Name and signature of Assembly Technician in Charge
Name and signature of Manufacturer or Legal Representative
Place / Date
A.5. Transitions
Table A-5 Installation, Assembly and Internal Control Form for Transitions (BASt, 2019; BASt, 2020a; FGSV, 2017;
all adapted)
1
Awarding Body
2
Contractor
3
Contract / Repair Contract /
Date
4
Location (Chainage of Control
Area)
5
Assembly Technician
6
Members/Partners
Installed System Type
Connected Safety Barrier 1
7
Connected Safety Barrier 2
8
118
Type of Works
Shipping □, Shipping & Assembly □, Assembly/Repair □
Weather Conditions
Dry □, Rain □, Temperature
o
C
SHC 118
304
9
Suitability, Selection and Installation of Safety Barriers
a
Installation manual
b
Installation in accordance with manual
c
Existence of CE certification
d
Working width and vehicle intrusion clear of obstacles
10
Installation of System
a
Standing base in accordance with the installation
b
Correct mounting of reinforcement including welds
c
Bolts in accordance with the instruction manual
d
Safety barrier aligned in terms of height
e
System aligned in plan view
f
Distance from highway edge line respected
11
Connections
a
Connection to safety barrier 1
b
Connection to safety barrier 2
Y/N
Y/N
Y/N
Remarks
Name and signature of Contractor
12
Name and signature of Assembly Technician in Charge
Name and signature of Manufacturer or Legal Representative
Place / Date
A.6. Terminals
Table A-6 Installation, Assembly and Internal Control Form for Terminals (BASt, 2019; BASt, 2020a; FGSV, 2017; all
adapted)
1
Awarding Body
SHC 304
119
2
Contractor
3
Contract / Repair Contract /
Date
4
Location (Chainage of Control
Area)
5
Assembly Technician
6
Members/Partners
Installed System Type
7
Type of Works
Shipping □, Shipping & Assembly □, Assembly/Repair □
8
Weather Conditions
Dry □, Rain □, Temperature
9
Suitability, Selection and Installation of Safety Barriers
a
Installation manual
b
Installation in accordance with manual
c
Existence of CE certification
d
Working width and vehicle intrusion clear of obstacles
10
Installation of System
a
Standing base in accordance with the installation
b
Bolts in accordance with the instruction manual
c
Safety barrier aligned in terms of height
d
System aligned in plan view
e
Distance from highway edge line respected
11
Connections
a
Connection to safety barrier
b
Anchorage operation
120
o
C
Y/N
Y/N
Y/N
SHC 120
304
Remarks
Name and signature of Contractor
12
Name and signature of Assembly Technician in Charge
Name and signature of Manufacturer or Legal Representative
Place / Date
A.7. Connection Hooks Control
Table A-7 Installation, Assembly and Internal Control Form for Connection Hooks Control (BASt, 2019; BASt,
2020a; FGSV, 2017; all adapted)
1
Awarding Body
2
Contractor
3
Contract / Repair Contract /
Date
4
Location (Chainage of Control
Area)
5
Assembly Technician
6
Members/Partners
Installed System Type
7
Type of Works
Shipping □, Shipping & Assembly □, Assembly/Repair □
8
Weather Conditions
Dry □, Rain □, Temperature
9
Hook and Toolkit Clamping Components
a
Type and dimensions
b
Tool/clamping device specifications
c
Number of installed hooks/anchors
d
Maximum assembly torque
SHC 304
o
C
Y/N
121
e
Number of controlled hooks
10
Tightening Torque Control and Documentation of Defective Hooks
#
Description of Installation
Location
Measured Torque
Remarks/Measures
Implementation Instructions:
Controlled selection of the assembly torque must be applied according to the relevant certificate through a
regulated tool/clamping device. If the assembly torque is not achieved corrective measures should be taken. The
torque achieved shall then be checked across at least 3 % of the hooks by means of a set clamping tool
(dynamometer). If it is found that more than 50 % of the hooks tested do not meet the requirements, all the
anchorages of the structure should be checked. If the number of defective hooks is less than 50 % at least two
additional hooks must be checked at the respective problematic supporting pole (steel safety barriers) or anchor
point (concrete safety barriers) as well as at the left and right adjacent supporting pole (steel safety barriers) or
corresponding anchor points (concrete safety barriers). If also in this case a hook does not meet the conditions
for proper anchorage then all the hooks of the problematic supporting poles or anchor points and all the hooks
of the adjacent supporting poles or anchor points must be checked and the incorrect hooks replaced.
Remarks
Name and signature of Contractor
11
Name and signature of Assembly Technician in Charge
Name and signature of Manufacturer or Legal Representative
Place / Date
122
SHC 122
304
A.8. Tolerances Form of In-Situ Concrete Barrier Installation
Table A-8 Installation, Assembly and Internal Control Form for Tolerances of In-Situ Concrete Barriers (BASt, 2019;
BASt, 2020a; FGSV, 2017; all adapted)
Project Location:
Date:
Heigh
t
above
paved
surfac
e
Criteria
Flatness
deviatio
n of
upper
side
Flatness
deviatio
n along
plan
view
Theoretical
Value
±3
cm
Chainag
e
Control at least every 100 m / 60 min
Tim
e
± 2 cm /
4m
Plan
view
positio
n
± 5 cm
± 2 cm /
4m
Reinforcement Location
± 6 cm
longitudin
al
±4
cm
later
al
Remar
ks
± 4 cm
from
theoretic
al
position
Control at least every 200 m /
180 min
Start
End
Total Concrete Consumption (m3)
Remarks
Name and signature of Contractor
Name and signature of Assembly Technician in Charge
Name and signature of Manufacturer or Legal Representative
Place / Date
SHC 304
123
Appendix B - Glossary of Terms
Acceleration Severity Index - Dimensionless parameter that assesses the impact against the
VRS.
Clear Zone - The total roadside border area, starting at the edge of the traveled way, that is
available for an errant driver to stop or regain control of a vehicle. This area might consist of
a shoulder, a recoverable slope, and/or a non-recoverable, traversable slope with a clear runout area at its toe.
Containment Level - Most unfavorable typical impact case that a VRS can successfully handle.
Crash Cushion - Road vehicle energy absorption device installed in front of one or more
hazardous locations to reduce the severity of impact.
Critical Distance - The distance from the highway edge line where VRS protection may be
required, provided that within this distance there are areas requiring protection or lateral
obstacles.
Decisive Distance - Distance between the highway edge line and the inner boundary of the
hazardous location.
Divided Highway - A highway that provides a median separation between the traffic in
opposite directions.
Durability - Ability of a product to maintain its required performance over time, under the
influence of foreseeable actions.
Dynamic Deflection - Maximum lateral displacement of the front face of the vehicle restraint
system from its initial condition.
Exit Box - The movement zone of the vehicle after the impact at the leading or trailing
terminal, determined during the impact test according to SASO EN 1317.
Exit Speed - Speed of the test vehicle after the impact with the test item, measured
perpendicular to the extended approach path at a point 12 m beyond the impact point.
Hazard Class - Risk classification of hazardous locations.
Hazardous Locations - Highway sections with compact lateral (roadside) obstacle at the
highway edge lines area or with risk for a vehicle to skid off the highway.
Highway Edge Line - The lateral boundary of the traffic space which coincides with the paved
edge line.
Impact Severity - The theoretical parameter that determines the physical stress, the severity
of injuries or the fatality risk of vehicle occupants.
Lateral Separating Island - An island located at the highway’s edge line which is meant to
separate same or opposite directions of traffic.
Manufacturer (synonymous with Producer) - Organization with legal responsibility for
placing a certification on a VRS product.
Median - A divider or island placed usually at the centerline of a highway which is meant to
separate opposite directions of travel.
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Obstacle - An item or hazard being protected from vehicular impact.
Pedestrian Restraint System - System installed to provide restraint for pedestrians.
Performance Class - Characteristics of vehicle restraint systems’ operation and behavior on
impact.
Permanent Lateral Displacement - Residual lateral deformation of leading and trailing
terminals as well as crash cushions during impact tests.
Portable Safety Barriers - Temporary safety barriers.
Posted Speed - The speed limit determined by law and shown on speed limit signs.
Protective Device - A vehicle restraint system type. This type may be one of the following:
safety barrier, terminal, transition, removable safety barrier, crush cushion.
Railings - Non vehicle restraint system installed alone or in combination with vehicle restraint
systems in bridges, retaining walls or similar structures for pedestrian or other user safety.
Redirection - Capacity of a restraint system to return a vehicle to the highway in a controlled
manner after an impact against such restraint system.
Roadside - Area beyond the traveled way (e.g. driving lanes) and the paved shoulder (if any)
of the roadway itself.
Rural Highway - A type of roadway normally characterized by lower volumes, higher speeds,
fewer turning conflicts, and less conflict with pedestrians.
Safety Barrier - Continuous vehicle restraint system installed alongside, or on the median area
of a highway.
Superelevation - Grade in the lateral direction of the highway pavement.
Support Structure - System used to support items of road equipment.
Terminal - The leading or trailing treatment of a safety barrier.
Theoretical Head Impact Velocity - Parameter that assesses the occupant impact severity
during vehicles’ collisions with vehicle restraint systems.
Traffic Space - Paved area in the highway that includes the traffic lanes, the inner and outer
paved shoulders, and the emergency lane.
Transition - Connection between vehicle restraint systems of different types, designs and/or
performances, or between vehicle restraint systems and unwavering structures.
Vehicle Intrusion - Maximum lateral lean (intrusion) of the impacting vehicle from the front
face of the vehicle restraint system, measured at a height of up to 4 m from the paved surface
during impact tests.
Vehicle Parapet - Safety barriers at the bridge and/or retaining walls areas where there is a
risk for a vertical drop and which can include additional protection and restraint for pedestrians
and other road users (combined vehicle/pedestrian parapet).
Vehicle Restraint System - Post crash, passive safety systems placed on highway areas aiming
to contain vehicles involved in run-off-road crashes and/or redirect them smoothly to the
highway.
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Working Width - Sum of the dynamic deflection and the structural width of the vehicle
restraint system.
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Appendix C - Abbreviations, Acronyms
ADT
Average Daily Traffic
ASI
Acceleration Severity Index
BCA
Benefit-Cost Analysis
BD
Bi-Directional
CC
Vehicle Restraint System Crash Cushion
CEN
European Committee for Standardization (also EN)
D
Dynamic Deflection
EN
European Standard (see CEN)
ERF
European Road Federation
HE
High Energy Absorbing Class of Support Structure
IPC
In-Situ Production Control
LE
Low Energy Absorbing Class of Support Structure
MASH
Manual for Assessing Safety Hardware
MD
Multi-Directional
MoTLS
Ministry of Transport and Logistic Services
NE
Non Energy Absorbing Class of Support Structure
NS
No Separation Collapse Mode
R
Backfill Type R for Support Structure, Rigid
RGA
Road General Authority
RoR
Runoff Road
S
Backfill Type S for Support Structure, Standard Aggregates
SASO
Saudi Standards Metrology and Quality Organization
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SB
Safety Barrier
SBStr
Safety Barriers on Structures
SD
Single-Directional
SE
Separation Collapse Mode
SSHIA
Special Solution at Highway Intersection Areas
TER
Vehicle Restraint System Terminal
THIV
Theoretical Head Impact Velocity
TL
Test Level
TR
Vehicle Restraint System Transition
TS
Technical Specification
VI
Vehicle Intrusion
VRS
Vehicle Restraint Systems
W
Working Width
X
Backfill Type X for Support Structure, Special Aggregates
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Appendix D - Units
SI Units
Imperial Units
Length
mm
Millimeter
cm
Centimeter
m
Meter
km
Kilometer
Area
cm2
Square centimeter
Volume
m3
Cubic meter
Weight
kg
Kilograms
Force
kN
Kilonewton
Time
s
Second
h
Hour
min
Minute
Temperature
°C
Degree Celsius
Angular
°
Degree
Other
km/h
Kilometers per hour
kJ
Kilojoule
Other
veh/h
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Vehicle per hour
129
veh/d
130
Vehicle per day
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