Toronto 
A new look at how young drivers react after consuming edible cannabis is raising questions about how well people judge their own impairment.
CNW Group/CAA South Central Ontario
A University of Saskatchewan study, funded by CAA, explored how the drug affects real-time driving behaviour, and the findings suggest many drivers may not recognize the risks until it’s too late.
Researchers monitored 50 participants between 19 and 30 years old, gathering 250 simulator assessments after each person consumed a 10mg THC edible. This age group already has the highest crash rates in Canada, and CAA says understanding how edibles affect them is an important step toward improving road safety.
Michael Stewart, Community Relations Consultant for CAA South Central Ontario, says the study helps shift conversations away from guesswork. He notes that many decisions about driving after cannabis use are still based on personal judgment rather than evidence.
The study found clear impairment in reaction time, lane keeping, and speed control. The most significant decline appeared around the 90-minute mark, a point when many users might already be behind the wheel. Only four per cent of participants felt safe to drive at that time.
However, these controlled findings don’t match what’s being reported on the road. A recent survey of 1,510 Ontario drivers found that nearly 20 per cent admitted to driving under the influence of cannabis. Even more concerning, 78 per cent of those who had driven high said they felt confident in their abilities, up 13 per cent from 2021. Many relied on their own signs of impairment, such as feeling tired or foggy, instead of avoiding driving altogether.
The survey also highlighted an increase in poly-use. Fifty-seven per cent of respondents said they combine cannabis with other substances, most often alcohol, but also painkillers, psilocybin, ecstasy, and MDMA.
Stewart stresses that confidence doesn’t equal safety and urges motorists to plan a way home if they consume any impairing substance.
