FREQUENTLY ASKED QUESTIONS ON CANNABIS USE AND ROAD SAFETY
What is the impact of cannabis use on driving? Do edible and smoked cannabis
products affect drivers in the same way? How should the law deal with drivers who take cannabis for
medical reasons? These are among the questions addressed today in a new policy briefing on cannabis
and driving, published by the EU drugs agency (EMCDDA) and the Canadian Centre on Substance
Use and Addiction (CCSA).
With cannabis policy evolving internationally, cannabis-impaired driving has become an increasingly
relevant issue. The new briefing aims to provide those concerned with policy in this field with an overview
of the latest knowledge and developments. The briefing draws on the evidence presented at the Third international symposium on drug-impaired driving, held in Lisbon on 23 October 2017. The event was a collaborative initiative of the EMCDDA, the CCSA, the US National Institute on Drug Abuse (NIDA) International Program and the
New Zealand Drug Foundation. Over 100 participants attended the event, which brought together
researchers, practitioners and policy experts from over 30 countries.
The briefing answers 15 questions grouped in four key areas addressed at the symposium:
Challenges for regulatory models
Drug screening, testing and detection
Preventing cannabis-impaired driving
Future perspectives for research and monitoring.
The briefing looks at the usefulness of biological and behavioural tests in assessing cannabis-related
impairment as well as the challenges they present. It describes how the effects of smoked cannabis differ
from those of edible cannabis and discusses the complexities arising when drivers mix substances
(e.g. cannabis and alcohol). The briefing also considers the various options available for responding to
cannabis-positive drivers and the need to complement penalties with education countering young
people’s misconceptions about the levels of risk involved.
With cannabis use no longer illegal in some jurisdictions (be this for medical or recreational purposes),
laws penalising cannabis-positive drivers may become similar to those penalising alcohol-positive drivers.
For example, many countries are working towards laws that establish maximum permissible blood-drug
limits. As in the case with alcohol, these laws would mean that any driver ‘over the limit’ would be
committing an offence and there would be no need to prove physical impairment. Whatever approach is
chosen, ongoing evaluation will be crucial.