The Safety Edge What is it? How does it work? What are the benefits? Mehdi Parvini Ken KenKochevar Kochevar SafetyDivision and Design Team Leader Sr. Pavement Engineer FHWA Office National Safety andPrograms Design Team LeaderOffice of Pavement Engineering & Specification Development FHWA Division Office Ph: (916) 498-5853 Ph: (916) 498-5853 Caltrans Pavement Management Program Ph:(916) 227-5848 MAKING PAVEMENTS SAFER and MORE DURABLE 2 36,700 Fatal Crashes per Year 2006-2008 Average – Source: FARS 122 530 228 68 98 162 447 399 383 223 635 136 148 970 3525 1071 782 250 489 385 905 1133 646 366 663 373 1421 114 563 DC DC=34 933 577 776 3084 857 797 1074 971 66 268 1387 382 215 344 1251 990 1472 869 67 2928 124 Average 40,409 Annual Fatalities 3 2008 Fatal Crashes (Based on FARS) 34,017 U.S. Fatal Crashes 17,818 U.S. Roadway Departures 4 59 people will die in a roadway departure crash in the United States today. 1 Fatality Every 24 minutes 5 13,242 Roadway Departure Fatalities on Two Lane Undivided Source: 2008 FARS Data Focused Solution: Low cost Two Lane roadways Roadway Departure 6 Are Drop-offs a Problem? Vehicle Re-entry 7 Head-on Roll Over Opposite Side Roadside Hazard 8 Was the drop-off the cause? 9 Clip of TTI drop off road test: http://fhwa.na3.acrobat.com/safetyedgedrop 10 11 12 Location of Drop-offs 1. Horizontal Curves 2. Near Mailboxes 3. Turnouts 4. Shaded Areas 5. Eroded Areas (Drainage) 6. Asphalt Pavement Overlay 13 Horizontal Curves 14 Mail Boxes 15 Shaded Areas Sunlight = Vegetation 16 Asphalt Overlay 17 The Safety Edge: A Practical Solution 18 The Hardware GDOT Version IV GDOT Version V 19 End Gate Springs 20 The Hardware Trans Tech Shoulder Wedge Maker TM www.transtechsys.com Advant-Edge TM www.advantedgepaving.com 21 Key Features Self Adjusting Spring 300 Forming Edge ½” Radius Leading Edge 450 Compound Angle 22 Clip of safety shoe being installed http://fhwa.na3.acrobat.com/seshoeinstall/ 23 Line Depicts extension of Pavement Surface o o 30 - 35 Line depicts a plane parallel to Pavement Surface from the toe of the wedge surface 24 Construction Clip Shoulders Construct Overlay Pull Shoulders Flush No Effect on Production Minimal Monitoring 12.5 mm or 9.5 mm SP 25 Clip of paving without Safety Edge http://fhwa.na3.acrobat.com/sewoshoe/ Clip of paving with Safety Edge http://fhwa.na3.acrobat.com/seshoe/ 26 Breakpoint on wedge Existing pavement edge Toe of wedge New graded shoulder 27 Breakpoint on wedge Toe of wedge Location of the existing pavement edge under overlay 28 Iowa PCCP Safety Edge 29 Increased Edge Compaction ? With Safety Edge Without Safety Edge 30 Edge Compaction Safety Edge No Safety Edge Six Condition After One Year In-Service 31 Durability 32 Benefits of A Safe Edge Temporary safety benefit during construction Permanent Solution for future drop-off re-emergence Reduce tort liability – Providing “Due Care” Minimal hardware, labor, or material costs Increased Pavement Edge durability 33 Safety Edge Implementation Standard Practice Projects Built State Evaluating Safety Edge States without activity Pool-fund States 34 Every Day Counts (EDC) Initiative • Initiated Spring of 2010 • EDC designed to identify and deploy innovation • Shortening Project Delivery • Enhancing Safety of our Roadways • Improving Environmental Sustainability • Safety Edge: 1 of 5 solutions • Goal: 40 states adopting Safety Edge by Dec. 2011 35 What can FHWA offer ? 10-12 demo projects for 2010-2011: Free loaner equipment Technical assistance Project documentation Promotional Material Specifications Tech Drawings 36 Safety Edge Detail Original Width Variable Width for Safety Edge HMA/PCC Lane or Shoulder Existing Lane or Shoulder Safety Edge Angle 30 Aggregate Shoulder or Shoulder Backing Existing Shoulder or Shoulder Backing Factors that Impact the Effectiveness of the Safety Edge • Edge drop off height • Type of highway (undivided, number of lanes) • Shoulder width • Design speed • Curve • Rumble strip • Ditch/guard rail at the edge Criteria for Using Safety Edge For demonstration projects: • All new and rehabilitation pavement projects that create pavement edge drop off more that 0.15 ft For subsequent projects: • Further crash data analysis is underway to come up with most efficient locations for the safety edge Safety Edge Specification The contractor shall attach a device to the screed of the paver that confines the material at the end gate and extrudes the asphalt material in such a way that results in a compacted wedge shape pavement edge of approximately 30 degrees (not steeper than 35 degrees). The device shall maintain contact to the road shoulder surface. It shall also allow for automatic transition to cross roads, driveways and obstructions. The device shall constrain the asphalt head reducing the area by 10 to 15% increasing the density of the extruded profile. Conventional single plate strike off are not allowed. The contractor may use the TransTech Shoulder Wedge Maker or the AdvantEdge or a similar device that produces the same wedge consolidation results. If the contractor uses a similar device, he must provide proof that his device has been used on previous projects with acceptable results or the contractor shall construct a test section prior to the beginning of work and demonstrate wedge compaction to the satisfaction of the engineer. Short sections of handwork will be allowed when necessary for transitions and turnouts or otherwise authorized by the engineer. This work will be included in the pay item Hot Mix Asphalt. Safety Edge Cost • Equipment – about $3,500 (one time expense) • Material – 1% to 2.5% of a typical overlay cost More Information http://safety.fhwa.dot.gov/roadway_dept/paveme nt/safedge/ www.pooledfund.org TPF-5(097) Evaluation of the Safety Edge Specifications and Drawings Safety Impacts of Pavement Edge Drop-offs: www.aaafoundation.org, September 2006 42 Challenge What will you do this year to make our highways safer ? Low Cost Focused Proven 43 We need your help! Questions??