BRIDGE RAILS : RECENT CRASH TESTS AND DEVELOPMENTS . PROCEEDINGS OF THE 1989 ANNUAL CONFERENCE OF THE ROADS AND TRANSPORTATION ASSOCIATION OF CANADA, CALGARY, ALBERTA, SEPTEMBER 17-21, 1989

Historically, longitudinal traffic barriers such as bridge rails have been designed for only one level of service. The strength test in NCHRP report no. 230 for this single level of service was a 4,500 lb. (2,040 kg) car impacting at 60 mph (98.6 km/hr) and 25 degrees. Crash testing of bridge rails was optional, but not required by the AASHTO Bridge Specifications. To be acceptable, bridge rail designs had only to meet the railing geometrics requirements and be able to resist a 10,000 lb (4,536 kg) static load. More recently, AASHTO has adopted a new "Guide specification for bridge railings" that contains three levels of performance, as defined by crash test results. This paper describes the crash test performance evaluations of a number of new bridge rail designs. Recommendations are given for the design of bridge rails that covers design loads, railing geometric considerations, and the design of the connections between the bridge rails and the decks. (Author/TRRL )