The end of a roadside guardrail must be designed so that it is not a hazard to occupants of a vehicle striking it and so that it absorbs energy in a crash and redirects the vehicle into a safe trajectory. A new report from the National Academies of Sciences, Engineering, and Medicine presents a design for evaluating the real-world performance of guardrail end treatments, determines the data required for the analysis, examines state data systems to determine whether the required data would be available, and identifies next steps for carrying out evaluations.

Evaluation of roadside safety devices that are in the field can help to ensure that they effectively reduce the risk of injuries and fatalities.  Crash testing -- the method currently used to evaluate such devices -- cannot reproduce the variety of characteristics that affect crash outcomes, the report says.  In-service data are necessary to determine the frequencies of various crash, installation, and site characteristics in order to determine the conditions that should be included in crash tests. In-service evaluation also is necessary to verify that devices in the field perform as they do in testing. Periodic evaluation is needed because vehicle, traffic, and road characteristics change over time and new device designs frequently come into use.

The report includes recommendations for how the U.S. Department of Transportation and the state departments of transportation should cooperate in undertaking a research program to validate and refine crash testing of guardrail end treatments and other roadside safety devices through in-service evaluation and simulation modeling.

DETAILS:

The report, In-Service Performance Evaluation of Guardrail End Treatments, is available for immediate release.  Media inquiries should be directed to the National Academies' Office of News and Public Information; tel. 202-334-2138 or email news@nas.edu.