Vehicle impact tests on frangible and yielding post designs of bridge parapets.

Two designs of post and rail bridge parapets have been developed which provide more positive containment of vehicles and better response after impact than conventional parapets. In one design the posts fracture at their bases at a predetermined transverse loading thereby minimizing the rolling motion of a large vehicle towards the parapet. In the second design the posts yield, bending at their bases under impact from a large vehicle but are not damaged by car impacts.