Driving within two hours of using marijuana has substantially increased, along with public concern, just one year following the legalization of marijuana in Canada, according to two new reports published by Traffic Injury Research Foundation (TIRF).

TIRF’s Road Safety Monitor 2019: Trends in Marijuana use among Canadian Drivers is an annual public opinion survey conducted by TIRF and co-sponsored by Beer Canada and Desjardins. The presence of marijuana among fatally injured drivers involved in crashes is reported in a second fact sheet, Marijuana Use Among Drivers in Canada, 2000-2016, also sponsored by Desjardins.

The RSM data represents one of the first comparisons of self-reported driving after using marijuana in Canada one year prior to legalization and one year following it. The analysis reveals the percentage of drivers who report driving within two hours of marijuana use increased to seven percent in 2019, up from 3.3 percent just one year ago.

“In the five years leading up to the legalization of marijuana, a generally increasing trend in use prior to driving has been clearly evident,” said Dr. Heather Woods Fry, TIRF Research Scientist. “The significant increase in past-year, self-reported use prior to driving would suggest much more intensive education and enforcement are needed.”

According to researchers, the steady increases in public concern about drug-impaired driving generally and, more specifically, marijuana-impaired driving in recent years could be reflective of growing awareness about the impairing effects associated with marijuana. Seven out of 10 Canadians (71.3 percent) were very or extremely concerned about drugged drivers according to the 2019 poll, up from 59.5 percent in 2014.

The researchers reveal that the concern is backed up by an examination of trends among fatally injured drivers tested for drugs; 15.9 percent were positive for marijuana in 2000 compared to 23.3% in 2016. In addition, almost two in five drivers killed in road crashes that tested positive for marijuana also tested positive for another substance which was most often alcohol.

“To make an equitable comparison using 2016 data only, the fact that 2.3 percent of Canadians reported driving within two hours of using marijuana, but 23.3 percent of drivers killed in road crashes tested positive for the substance should give us all pause,” said Dr. Ward Vanlaar, Chief Operating Officer of TIRF. “In light of the increase to 7 percent in 2019, Canadians who doubt marijuana has some effect on crash risk should consider the math before getting behind the wheel.”

Download the TIRF Fact Sheets:

Road Safety Monitor 2019: Trends in Marijuana use among Canadian Drivers

Marijuana Use Among Drivers in Canada, 2000-2016