In 1998 a field study funded by the Federal Highway Research Institute of Germany (BAST) was conducted with drivers at discotheques. These subjects were contacted by researchers from the Centre of Traffic Sciences, Würzburg (IZVW) and asked to participate in a short interview concerning drugs and driving. N = 2,779 subjects were included in the study. Of these, N = 1593 were driving at the evening of the study ("current drivers"). The remaining N = 1186 were not driving at the evening of the study but had been driving at similar occasions ("potential drivers"). Comparing these two groups gives an indication whether people who use illegal drugs or alcohol are more likely to refrain from driving or not. The results show that alcohol strongly influences the decision to drive as the percentage of subjects with alcohol is much larger in potential drivers than in current drivers. For subjects using drugs, no difference is found between current and potential drivers indicating that drug use does not stop these subjects from driving. Subjects who had consumed both drugs and alcohol were found more often in potential drivers than in current drivers. As this effect is comparable in magnitude to the effect of alcohol, alcohol use and not drug use is the factor hindering these subjects from driving.
Abstract