Procedures are presented for conducting passenger vehicle crash tests of roadside appurtenances. Appurtenances covered by these procedures are (1) longitudinal barriers such as bridge rails, guardrails, median barriers, transitions, and terminals; (2) crash cushions; and (3) breakaway or yielding supports for signs and luminaires. The purpose of the procedures is to promote the uniform testing of roadside appurtenances so that highway engineers may confidently compare safety performance of two or more designs that are tested by different agencies. The procedures are guidelines that describe how an appurtenance should be tested and evaluated. The procedures are directed to only the safety or dynamic performance of an appurtenance; other service requirements of economics and aesthetics are not considered in the evaluation. These procedures are devices to subject highway appurtenances to severe or worst passenger vehicle impact conditions rather than to "typical" or the more predominant highway situations. Appurtenances developed for these conditions are believed to provide a moderate level of protection to occupants of large vehicles. Guidelines are presented for evaluating safety performance. Three appraisal factors are (a) structural adequacy, (b) impact severity, and (c) vehicle trajectory hazard. Depending on the appurtenance's function, it should contain, redirect, and or permit penetration of the impacting vehicle in a predictable manner to satisfy structural adequacy requirements. Impact severity relates to the degree of hazard to which occupants of the impacting vehicle would be subjected and is measured in terms of vehicle accelerations and momentum changes. Vehicle trajectory hazard relates to the probable involvement of other traffic because of the postcrash path or position of the impacting car. The highway engineer should be aware that vehicle crash tests are complex experiments and are difficult to replicate due to imprecise control of critical test conditions and the sometimes random and unstable behavior of dynamic crash and fracture mechanisms. Accordingly, he should recognize the limitations of the tests and exercise care in interpreting the results.

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 27 p.
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00173172
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: May 3 1978 12:00AM