Florida’s Turnpike Enterprise
High Tension Median Cable Barrier
Pilot Project
William H. Cook, P.E.
Florida’s Turnpike Assistant
Roadway Engineer
Florida Turnpike Enterprise
Miami (MP 0) to
Wildwood (MP 309)
Limited access
tolled facility
Begins on Heft in
Miami-Dade and
ends at I-75 in
Central Florida
Approximately 309
mainline miles
Florida’s Turnpike Enterprise Median
Protection Program
Median Safety Study
Performed in 1999
Study Identified
median protection
needs.
Guardrail was the
recommended barrier
for median cross over
protection.
Florida’s Turnpike Enterprise Median
Protection Program
Initial Median
Protection Program
was included with
resurfacing projects
using double face
guardrail.
Florida’s Turnpike Median Crash Data
Florida's Turnpike Median Crash Data
SR 91
2001
2002
2003
2004
2005
Fatal Crossover Crashes
12
17
26
25
4
Fatalities
18
21
34
46
4
Florida’s Turnpike Enterprise Median
Protection Program
Policy change in 2004
All medians on
Florida’s Turnpike to
be closed by June
2005
Guardrail was the
preferred barrier
FDOT interested in
H.T.C.B as alternate
barrier
Florida’s Turnpike Enterprise Median
History with H.T.C.B in Florida?
- ZERO
Predominantly used W beam or Concrete
Barrier Wall
High Tension Cable Barrier Pilot Project
High Tension Wire Rope Safety Fence (Cable
Barrier) was added to Miami Dade Median
Protection Project as Pilot for FDOT.
MP 3 to MP 10
Goals:
To evaluate cable barrier as an alternate
roadside barrier. (Safety, cost, time)
Evaluation includes design, construction and
maintenance advantages/disadvantages of cable
barrier
HEFT Typical Section MP 3 TO MP 10:
Four lane divided freeway w/
64 to 88 foot median width
Design Speed = 70 mph w/ AADT = 60,000 vph
1 :6
24 ft
64 ft to 88 ft
24 ft
High Tension Cable Barrier Pilot Project –
Systems Evaluated
Brifen USA: MP 3.2 to MP 5.2 – Approximately
10,200 ft of barrier
High Tension Cable Barrier Pilot Project Systems Evaluated
Safence: MP 5.2 to MP 6.8 – Approximately
7,200 ft of barrier
High Tension Cable Barrier Pilot Project Systems Evaluated
CASS: MP 6.8 to MP 9.2 – Approximately
10,485 ft of barrier
Florida’s Turnpike High Tension Cable
Barrier – Design
Post
Spacing
Brifen,USA
CASS
SAFENCE
10’ 6”
10’
8’ 3”
Deflection
10’ max per 10’ max per 10’ max per
spec
spec
spec
Location
12’ from
edge of
travel min.
4
Number of
Cables
12’ from
edge of
travel min.
3
12’ from
edge of
travel min.
4
Florida’s Turnpike High Tension Cable
Barrier – Design
All systems to be NCHRP – 350 TL-3 min with
an FHWA acceptance letter.
Specifications were developed using FHWA
acceptance letter, manufacturers specification
literature, site requirements, and input from
other states.
End terminals had to be NCHRP – 350
approved or protected with existing guardrail.
Minimal impact to existing median drainage.
Asphalt mowing strip was provided
Florida’s Turnpike High Tension Cable
Barrier – Design
End Terminals – Brifen, USA and CASS had
NCHRP 350 approved end terminals,
SAFENCE was not NCHRP approved at the
time and required protection.
Soil conditions were issue for end terminals –
limerock and unsuitable soils.
CASS system has end terminal that can be
incorporated into guardrail end terminal –
used at one location.
Florida’s Turnpike High Tension Cable
Barrier – Specification
One specification for each manufacturer
Maximum of 10’ deflection was allowed
Post spacing was based on FHWA acceptance
letter and deflection requirement.
All cable systems must be approved for
NCHRP - 350 TL-3 minimum.
Contractor was required to provide letter from
manufacturer that the design and materials
installed met manufacturers requirements.
Florida’s Turnpike High Tension Cable
Barrier – Specification
All post were to be socket type, no driven
post
All manufacturers were to perform on site
training of construction and maintenance
personnel and provide certification letters for
each construction and maintenance individual
trained
Tension logs were required five days after
initial tension
Tension meters used on site were to become
property of FDOT
Florida’s Turnpike High Tension Cable Barrier –
Construction Cost
Median Protection projects were let Lump
Sum – no bid items were require
Contractor supplied an estimate of $19 per
foot for cable barrier after bid award.
Current estimate for H.T.C.B is $15 per foot
for latest cable project – Canal Protection.
Florida’s Turnpike High Tension Cable Barrier –
Construction
Contractor: J Fletcher Creamer & Son, Inc.
Contract Time was 276 days
Project included guardrail and H.T.C.B. installation.
Tension Tolerance for cables after installation was a problem
- major
Two of the three systems experienced inadequate tension at
the first tension reading.
Two of the three systems required continuous tension
monitoring during and after construction for tension.
Two systems required repeated field tensioning to reach and
maintain the correct cable tension.
One tension meter required repair.
Ambient air temperature became a major concern when
taking tension readings – tension varied from top rope to
bottom rope in summer temperature with asphalt mowing
strip.
Brifen, USA
SAFENCE
CASS
Florida’s Turnpike High Tension Cable Barrier –
Maintenance
Maintenance personnel
recommend socketed posts
Maintenance has experienced
a learning curve with repairs.
Cost of maintenance was
been an issue – higher than
anticipated.
Average time to repair runs
15 to 30 minutes.
Average number of posts to
repair – 6
Most posts repaired – 56
Florida’s Turnpike High Tension Cable
Barrier – Maintenance
Tension tracking of cables
is concern to maintenance
personnel due to tension
issues during construction.
All H.T.C.B. systems are
holding the proper tension.
Issue has been resolved.
No cable damaged to date.
Qualified maintenance personnel – training
required.
Anticipate maintenance costs to decline.
Florida’s Turnpike High Tension Cable
Barrier – Maintenance
Contract Issues
≤ 4 Posts Repair
≥ 4 Posts Repair
Special End Terminal
Work not Included:
Re-Tensioning & Testing
Standard End Treatments (protected)
Video
Maintenance repair
Start time 9:15 A.M.
8 posts repair
Maintenance Video
High Tension Cable Barrier Pilot Project Performance
From May 2005 to April 2006
20 reported impacts
0 penetrations
0 fatalities due to crossover
Florida’s Turnpike High Tension Cable
Barrier – Impact photos
First vehicle to impact cable barrier – March
2005 – no injuries
Florida’s Turnpike High Tension Cable
Barrier – Impact phots
Left tire mark
Florida’s Turnpike High Tension Cable
Barrier – Impact photos
Florida’s Turnpike High Tension Cable
Barrier – Impact photos
Florida’s Turnpike High Tension Cable
Barrier – Impact photos
Florida’s Turnpike High Tension Cable
Barrier – Impact photos
Florida’s Turnpike High Tension Cable
Barrier – Impact photos
Florida’s Turnpike High Tension Cable Barrier –
One year Evaluation - Conclusion
All three systems have performed well for all
impacts – no crossovers or injuries.
Cable Tension tolerances – need to clearly
define for construction and maintenance.
Ambient air verses material temperature –
which should be used –manufacturer input.
Deflection - real world vs. test environment
Tension log - additional maintenance – was
not anticipated
Questions?
Contact:
William H. Cook, P.E.
Florida’s Turnpike Enterprise
(407) 532-3999 Ext. 3640
William.cook@dot.state.fl.us