There is considerable debate concerning the effects of cannabis on driving and whether it has a causal role in traffic accidents. Although there is some evidence showing that cannabis impairs psychomotor performance, epidemiological studies suggest that there is a limited increase in accident risk associated with the use of cannabis alone. Cannabis used with alcohol however does appear to significantly increase accident risk. Whilst survey research has documented the proportion of people, particularly younger people, who use cannabis, there are few reports examining the frequency with which people drive while affected by cannabis. The research reported in this paper was designed to address this issue directly. A survey of 67 cannabis users in Melbourne was conducted in which participants were questioned at length about their patterns of cannabis and alcohol use and driving, and their attitudes regarding driving while intoxicated. The participants drive more frequently after using cannabis alone than after using cannabis with alcohol. In terms of the effects of these drugs on driving skills, these participants believed that cannabis with alcohol is much more dangerous than cannabis alone. (a) For the covering entry of this conference, please see ITRD abstract no. E202275.
Abstract