Recent Developments in Roadside Crash Cushions

Collision with a fixed object is the leading source of fatalities on the Interstate Highway System and other freeways. Among the efforts to reduce this toll has been the development and installation of impact attenuators in a number of states at elevated exit ramps. Design criteria presently used by the Federal Highway Administration are intended to result in barriers which will result in survivable impacts for the vast majority of high speed collisions. Field data relating to these design criteria are presented. Accident experience to date with these barriers is presented and has confirmed the expectation of their potential to significantly reduce accident severity. Further research is underway to extend the list of roadside conditions for which such barriers would be a cost effective lifesaving tool.