Develop Guardrail to Rigid Barrier Transition Attached to Bridge or Culvert Structure

A secondary roadway often intersects a primary roadway near a bridge end. When this occurs, the intersecting roadway or driveway is often too close to the bridge end to allow for proper transition from flexible rail to rigid rail and still terminate the run of metal beam guard fence. The minimum system required to protect a rigid bridge end on a high speed roadway would be a Test Level 3 (TL-3) transition and a TL-3 metal beam guard fence end treatment. The current high speed transition is approximately nineteen (19) feet long and the approximate length of metal beam guard fence end treatment is fifty (50) feet long, for a total of sixty-nine (69) feet in length. In situations where it was appropriate, if there was a transition from flexible rail to rigid rail that attached to the culvert or bridge deck, the rigid rail would end on the bridge before the end of the bridge, and start the transition on the culvert or bridge deck. This would allow TxDOT to reduce the required distance between the end of the bridge and the intersecting roadway or driveway to a maximum length of fifty (50) feet. This is inclusive of many of the situations that TxDOT faces. Many of these situations end up compromising safety of the drivers in one way or the other because it forces the designer to choose between protecting the drivers from steep slopes or drop-offs, or protecting them from the blunt end of the bridge rail. The research results consists of the following: (1) Allow the designer an option that often protects both the steep slopes and the blunt end. (2) Expand the uses of the one-of-a-kind radius rail that TxDOT has developed. The expanded use of the radius rail system has the potential to save lives as well. (3) Offer options to a problem that will provide better safety to the traveling public and reduce costs associated with creating a detail to handle this issue on a case-by-case basis when it arises. The purpose of this project will be developing and testing the Manual for Assessing Safety Hardware (MASH) TL-3 transition that can be anchored to the top of a concrete deck or culvert.


  • English


  • Status: Completed
  • Funding: $360090
  • Contract Numbers:


  • Sponsor Organizations:

    Texas Department of Transportation

    125 E. 11th Street
    Austin, TX  United States  78701-2483
  • Project Managers:

    Odell, Wade

  • Performing Organizations:

    Texas Transportation Institute

    Texas A&M University System
    3135 TAMU
    College Station, TX  United States  77843-3135
  • Principal Investigators:

    Williams, William

  • Start Date: 20170901
  • Expected Completion Date: 20190430
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01648611
  • Record Type: Research project
  • Source Agency: Texas Department of Transportation
  • Contract Numbers: 0-6954
  • Files: RiP, STATEDOT
  • Created Date: Oct 20 2017 10:27AM