Cannabis and psychomotor performance: a rational review of the evidence and implications for public policy.

Public policy debates regarding cannabis law reform, such as those surrounding the limited use of the plant for therapeutic purposes or the broader issue of legalizing and regulating personal, non-medical cannabis consumption by adults, invariably invoke the question: ‘How does society address the public’s growing concerns about cannabis consumption and driving?’ The subject is one that warrants a response, particularly by those advocating for various forms of cannabis liberalization and regulation. In 1996, the Board of Directors of the National Organization for the Reform of Marijuana Laws (NORML) acknowledged its opposition to the notion of operating of a motor vehicle while under the influence cannabis, ratifying a strict ‘no driving’ clause to the organization’s ‘Principles of Responsible Cannabis Use’. This provision states, ‘Although cannabis is said by most experts to be safer with motorists than alcohol and many prescription drugs, responsible cannabis consumers never operate motor vehicles in an impaired condition.’ Nevertheless, questions remain regarding the extent to which cannabis intoxication influences psychomotor performance and to what degree cannabis consumption may play a role in on-road traffic accidents. Questions also persist regarding the implementation of sensible and effective public policies to better identify cannabis-influenced driving behaviour and, ideally, to deter persons from engaging in this activity. This paper will attempt to summarize much of the available contemporary literature in order to better address these concerns and provide suggestions for ways society can better implement rational and evidence-based policies to address and deter cannabisinfluenced driving behaviour.