RECOMMENDED PROCEDURES FOR VEHICLE CRASH TESTING OF HIGHWAY APPURTENANCES

This report which is a synthesis of existing information on barrier technology, test methods, and human tolerance, recommends procedures for conducting passenger vehicle crash tests of roadside appurtenances (longitudinal barries such as bridges rails, guardrails, median barriers, transitions and terminals; crash cushions; and breakaway or yielding supports for signs and luminaires), and provides a commentary on these procedures. The procedures (devised to subject the appurtenances to severe conditions rather than to typical highway situations) which aim to promote uniform testing of such appurtenances, are directed to test only the safety or dynamic performance. Three appraisal factors are considered: (a) structural adequacy, (b) impact severity, and (c) vehicle trajectory hazard. Depending on the specific appurtenance function, it should contain, redirect, and/or permit penetration of impacting vehicle in a predictable manner to satisfy structural adequacy requirements. Impact severity relates to the degree of hazard to which the 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. Details are given of the testing facility, the test article, vehicle, and test conditions. The data acquisition systems and performance evaluation are detailed. Definitions are presented of the longitudinal traffic barriers, crash cushions and breakaway or yielding supports, and comments are made (on the testing facility, highway appurtenance, vehicle, test conditions, data acquisition systems, performance evaluation and report) which provide an insight into the rationale used in arriving at the recommendations.