Alcohol related accidents: characteristics, 'causes' and countermeasure implications

In Victoria, BAC's derived from tests taken from injured persons by hospital and coronial personnel are matched with accident data derived from police reports. The 1978 data file, comprising 6305 accidents, was analysed to determine the incidence and nature of alcohol related accidents. One in three accidents was alcohol related. However, most (83 per cent) alcohol related accidents occurred at night, a finding to be expected from our knowledge of the pattern of alcohol consumption. Among night time accidents, one in two was alcohol related. Since traffic composition, density and speed - and hence, exposure to particular forms of risk - differ at night, inferences concerning the causal role of alcohol can only be made after controlling for exposure. The analysis was therefore restricted to night time accidents and was conducted separately for 'urban' and 'rural' roads. Alcohol was over represented, on both 'urban' and 'rural' roads, among single vehicle accidents, in particular among 'run off road' and 'struck parked vehicle' accidents. Alcohol was under represented among multi vehicle collisions at intersections. Among the 'ran off road' accidents alcohol was significantly more prevalent in those that occurred on curved sections of road. Over three quarters of the accidents in which a single vehicle ran off the road on a curve were alcohol related. These accidents alone account for 22 per cent of all night time alcohol related accidents. The possibility of preventing such accidents through improvements to roadway delineation warrants investigation. Almost three quarters of the accidents in which a vehicle struck a fixed object, such as a utility pole or a tree, were alcohol related. In this sense, providing a more forgiving road environment is an important alcohol countermeasure.