The severity of off-road crashes is measured and compared according to whether they occur with a protected hard shoulder or an unprotected one. The safety indicator used is the presence of at least one injured person inside the vehicle running off the road. The authors have at their disposal a database describing about 50,000 crashes with and without casualties, representing 11 years of recording on the major highways between Paris and the South of France. The severity of crashes where vehicles run off the road onto shoulders is on average significantly higher in the absence of a safety barrier. Higher values of severity are connected with vehicles which run-off the road in the presence of embankments or ditches (given the fact that it is already systematically equipped for differences in level above 4 m or in the presence of punctual obstacles). These results take into account the typology of the crash, of highway characteristics and traffic conditions at the time of the crash. Systematic equipment of highway hard shoulders appears to be beneficial as a whole within the infrastructure and European traffic conditions, with a better control of the consequences suffered due to off-road crashes. (A)
Abstract