Procedures are presented for conducting vehicle crash tests and in-service evaluation 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 and in-service evaluation of roadside appurtenances so that highway engineers may confidently compare safety performance of two or more designs that are tested and evaluated by different agencies. These procedures are guidelines that describe how an appurtenance should be tested and evaluated; the selection of specific new, existing, or modified appurtenances for testing and evaluation, the establishment of acceptable performance criteria are policy decisions that are beyond the purview of this document. These procedures are devised to subject highway appurtenances to severe vehicle impact conditions rather than to "typical" or the more predominant highway situations. For vehicle crash testing, specific impact conditions are presented for vehicle mass, speed, approach angle, and point on appurtenance to be hit. Vehicle types considered are mini-compact, subcompact, and standard size passenger sedans, intercity and utility type buses, and tractor-trailer cargo trucks. Impact speeds range from 20 to 60 mph (32 to 97 kph), and approach angles vary from 0 to 25 deg. Three appraisal factors are presented for evaluating the crash test performance: structural adequacy, occupant risk, and vehicle after-collision trajectory. Depending on the appurtenance's function, it should contain, redirect, or permit controlled penetration of the impacting vehicle in a predictable manner to satisfy structural adequacy requirements.
Abstract