Epidemiological aspects of fatal and severe injury urban freeway crashes

Two types of crashes are common on urban freeways : in - lane rear - end impacts with stopped or slowed vehicles and those where a vehicle leaves the roadway (and road shoulder) and impacts with obstacles outside traffic lanes. Crashes resulting in a fatal or severe injury to a vehicle occupant were identified from crash records in the regional office of the California Department of Transportation for the 1,500 miles of freeways in Los Angeles, Ventura, and Orange counties, California, for 1984 and 1985. Selected road chracteristic were assessed and traffic - volume data obtained for these freeways to determine the relationship of these types of crashes to freeway features. (AU)