Alcohol, driver performance and crash involvement

Abstract

Driver performance has been shown to be affected by low levels of alcohol in the blood. Deterioration in the performance of skills related to driving has been demonstrated at even lower blood alcohol levels. Most drinking drivers have a low or very low blood alcohol level and so one would expect that they would account for a substantial percentage of those drinking drivers who are injured in a crash. However that is not so; drivers with a low BAC comprise a relatively small percentage of those drinking drivers who crash and are injured. The reason for this may lie in the exponential increase in the risk of crash involvement with increasing BAC above a level of about 0.05. This possibility is explored in the paper using data from roadside BAC surveys and the BAC levels of fatally injured drivers and those admitted to hospital in the Adelaide metropolitan area. The implications of the findings for the setting of legal BAC limits, the efficiency of police enforcement, and minimisation of the societal harm caused by drink driving are discussed.