Crashworthiness of Roadside Hardware on Curbed Roadways

Roadside hardware is often installed alongside curbed roadways. The standardized full-scale roadside hardware crash test procedures, however, do not normally include curb near or around the tested roadside safety feature. Although it is generally recommended to not install roadside safety features behind curbs, it is often necessary to do so along roadway corridors where curbs are needed. Some previous research examined the effects of curbs in front of longitudinal barriers but there is relatively little known about the effect curbs on the impact performance of common roadside safety features, especially guardrail end terminals, crash cushions, and breakaway hardware. The objective of this project would be to determine the effect of curbs on the impact performance of various roadside hardware devices. The approach could be to use in-service performance evaluation, full-scale crash testing, computer simulation or some combination of these methods. There is a need to develop objective guidance for the placement of roadside safety features in addition to w-beam guardrail in combination with curbing. This research will build on the guidance provided in the AASHTO Manual for Assessing Safety Hardware (MASH), the nearing completion NCHRP 22-33, “Multi-State In-Service Performance Evaluations of Roadside Safety Hardware,” and the guidance documented in NCHRP Report 357, Recommended Guidelines for Curb and Curb–Barrier Installations, to expand the body of knowledge beyond w-beam and curb combinations. The need to identify the most common safety devices and the effect of a curb on the functionality of the device will provide a measure of assurance in the choice and placement of traffic safety devices and a higher level of safety for the traveling public. State DOTs continue to strive to reduce the frequency and severity of run off the road crashes while balancing community and environmental needs, accommodation of utilities, and effective use of limited transportation budgets. This research will quantify the crash risk and will provide guidance which allow engineers to balance the competing need for both curbing and roadside safety features. It is anticipated that the results of this research will be incorporated into a future update of the AASHTO Roadside Design Guide. State DOTs may utilize this research as a foundation for policy development for the use of curbing in combination with roadside safety features.


  • English


  • Status: Proposed
  • Funding: $400000
  • Contract Numbers:

    Project 22-50

  • 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
  • Project Managers:

    Jared, David

  • Start Date: 20200520
  • Expected Completion Date: 0
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01739671
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 22-50
  • Files: TRB, RiP
  • Created Date: May 18 2020 3:05PM