Government of Canada invests in more research to study effects of cannabis on drivers

News release

July 3, 2018
Ottawa, Ontario
Public Safety Canada

Drug-impaired driving has been on the rise since police-reported data became available in 2009, and it is a major contributor to fatal road crashes in Canada. According to a 2017 Canadian Centre on Substance Use and Addiction-led study, there is substantial evidence indicating that driving after cannabis-use increases collision risk significantly (Estimating the Harms and Costs of Cannabis-Attributable Collisions in the Canadian Provinces, 2017). However, more needs to be done to gather evidence on how exactly cannabis impacts drivers.

The Honourable Ralph Goodale, Minister of Public Safety and Emergency Preparedness, today announced that Public Safety Canada is providing $919,065 over three years to the Centre for Addiction and Mental Health (CAMH) to help advance scientific knowledge on the impacts of cannabis on drivers ranging in age from 19 to 45.

This study will use simulated driving to help:

  • Determine how increased levels of THC (the main active ingredient in cannabis) in blood and oral fluid can impact a driver, including his or her ability to anticipate hazards; level of risk-taking behaviour; reaction time; and position and speed on the road.
  • Identify differences that may exist between the ages and genders of drivers, THC levels and driving impairment.

The results of the study will further inform Government of Canada’s policy on cannabis and driving, and public education and awareness material about the dangers of drug-impaired driving. The study will be completed by June 2020.


“Drug-impairment is a serious concern today – it’s a major contributor to fatal road crashes. To combat this potential deadly risk, the government is investing in new training and new tools for law enforcement, strengthening our laws and raising awareness about the dangers of driving while impaired by cannabis. We are also investing in new research to help better understand how cannabis impacts drivers and inform our work to keep our roads safe.”

– The Honourable Ralph Goodale, Minister of Public Safety and Emergency Preparedness

“While we have known for a long time that cannabis use affects our ability to drive, more in-depth and targeted knowledge is necessary to set limits for blood concentrations of THC. This research will enable us to set such limits, comparable to those which were set for alcohol several decades ago.”

– Professor Bruna Brands, Research Scientist, Health Canada and Collaborating Scientist, CAMH

“One of the key recommendations of the CAMH Cannabis Policy Framework is the need to develop a comprehensive strategy to prevent cannabis-impaired driving. This research is an important component of an evidence-informed approach to prevention, education and enforcement.”

– Dr. Catherine Zahn, President and CEO, CAMH

Quick facts

  • Drug-impaired driving is illegal in Canada and will remain illegal after cannabis is legalized and regulated.
  • The number and rate for almost all drug-impaired driving violations increased in 2016. In total there were 3,098 drug-impaired driving violations in 2016, 343 more than the previous year. (Statistics Canada, Juristat, July 24, 2017)
  • Among Canadians who have used cannabis, 28 per cent reported having operated a vehicle while under the influence. (Baseline Survey on Awareness, Knowledge and Behaviour Associated with Recreational Use of Marijuana – Final Report, Submitted to Health Canada, EKOS RESEARCH ASSOCIATES INC. September 2, 2016)
  • Law enforcement officers are trained to detect drug-impaired driving using Standard Field Sobriety Testing (SFST) and Drug Recognition Expert (DRE) evaluation; and enforce drug-impaired driving laws.
  • Since July 2008, under the Criminal Code, police can perform compulsory roadside checks and assessments, using Drug Recognition Experts, if they suspect a driver has drugs in their body. Failure to comply with the demand may result in criminal charges.

News Release