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 Brifen,USA CASS SAFENCE Post Spacing 10 6 10 8 3 Deflection 10 max per spec 10 max per spec 10 max per spec Location 12 from edge of travel min. 12 from edge of travel min. 12 from edge of travel min. Number of Cables 4 3 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