Break-away overhead sign bridges, preliminary crash testing. Paper presented at the 50th Annual Meeting of the Highway Research Board HRB, 1971.

This paper reports the results of eight vehicle crash tests and evaluates the behaviour of an Overhead Sign Bridge containing break-away devices to loads imposed during collision by automobiles. Vehicle weights ranged from 2100 to 4880 pounds; the most severe test was with a 4880 pound vehicle at 54 mph. It was found necessary to install tube type energy dissipaters to protect the lower chord members against damage from the rotating leg of the truss.