Executive Summary

On the heels of several decades of successful efforts to understand and reduce the magnitude of the problems associated with driving after consuming alcohol, driving while impaired by other psychoactive substances has emerged as a road safety issue of its own. There are a wide variety of substances that have the potential to adversely affect the cognitive and behavioural skills required to operate a vehicle safely. The list of substances includes many illegal drugs (e.g. cannabis, ecstasy), psychotropic medications (e.g. benzodiazepines, opiates), and some over-the-counter preparations (e.g. antihistamines, cough and cold remedies). Despite the apparent similarity with the problem of alcohol use and driving, drug-driving1 presents a whole new array of challenges for research, policy, and programmes.