Recommended Guidelines for the Selection of Test Levels 2 Through 5 Bridge Rails

The AASHTO Manual for Assessing Safety Hardware (MASH) and NCHRP Report 350: Recommended Procedures for the Safety Performance Evaluation of Highway Features, contain 6 test levels for evaluating the safety performance of longitudinal barriers, including bridge rails. When NCHRP Report 350 procedures were adopted by the FHWA, the criteria for evaluating bridge rails that was contained in the AASHTO Guide Specification for Bridge Railings (1989) were superseded. However, there is currently no specific guidance on when to use the different test levels of bridge rails. In addition, the AASHTO LRFD Bridge Design Specification contains additional criteria for the height of the railings that may unnecessarily limit the selection of tested bridge railings. There is a need for nationally recognized guidelines in order to promote consistency among the states. For example, many states use TL-4 railings while others use TL-3 railings as their standard for high-speed highways. The use of Test Levels 5 and 6 railings is at the discretion of the states, usually in locations with heavy truck traffic and an increased potential for ran-off-road crashes (such as on curves). There is also very little guidance concerning the use of TL-2 railings on lower speed facilities. The objective of this project was to develop recommended guidelines for the selection of Test Levels 2 through 5 bridge rails considering in-service performance.


  • English


  • Status: Completed
  • Funding: $350000
  • Contract Numbers:

    Project 22-12(03)

  • Sponsor Organizations:

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001

    American Association of State Highway and Transportation Officials (AASHTO)

    444 North Capitol Street, NW
    Washington, DC  United States  20001

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Performing Organizations:

    Roadsafe LLC

  • Principal Investigators:

    Ray, Malcolm

  • Start Date: 20100720
  • Expected Completion Date: 20140531
  • Actual Completion Date: 20140531

Subject/Index Terms

Filing Info

  • Accession Number: 01755388
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 22-12(03)
  • Files: TRB, RIP
  • Created Date: Oct 26 2020 3:12PM