The fear of increased, impaired driving and potential for harm is one of many persistent arguments against the legalization of cannabis that those against reform tout consistently. However, new research looking at two provinces in Canada found that cannabis legalization, in fact, did not result in an increase in driving-related injuries among adults and youth.
The leader of the study published in the academic journal Drug and Alcohol Dependence, Russell Callaghan, and a psychologist at the University of Northern British Columbia., reported, “I thought recreational marijuana use would lead to a greater likelihood of car accidents and injuries, but we didn’t see that.”
Canada legalized cannabis back in 2018, so researchers looked over 239,673 reports on ambulatory patients from Alberta and Ontario, which are the only provinces in the country that document all emergency room visits, in the four years leading up to October 2018. The team then compared the number of moderate-to-severe car crash injuries to those on record during the 14 months following legalization.
They looked at all drivers and youth drivers, youth defined as ages 14-17 years in Alberta and 16-18 in Ontario.
Callaghan points to the argument that legalization will lead to increased traffic-related harms, especially among youth, confirming, “We found no increase in the overall rate of car accident injuries in adults or youth.” The findings also mirror recent studies in the U.S. that came to similar conclusions.
The weekly average of Alberta motor vehicle accident injuries recorded varied between five and 20, which was the same as before cannabis was legal. In Ontario, injury counts from vehicle collisions varied between 10 and 30 consistently. Callaghan also said, if all ambulatory visits to emergency rooms were recorded, he expects that the data would mirror the trend in British Columbia.
Callaghan admitted that the findings were “somewhat surprising,” with the prediction that legalization would increase cannabis use, cannabis-impaired driving in the population and that the pattern leads to increased traffic injuries and emergency hospital visits.
“It’s possible the results may be due to the deterrent effects of stricter federal legislation, such as Bill C-46, coming into force shortly after cannabis legalization,” he added.
The bill rose to prominence shortly after legalization in Canada, imposing new traffic safety laws and more severe penalties for impaired driving due to cannabis, alcohol and combined cannabis and alcohol use. It includes $1,000 fines for those with THC blood concentrations between two and five nanograms per milliliter of blood.
Scott Macdonald, a scientist with the Canadian Institute for Substance Use Research at the University of Victoria, also worked on the sstudy and pointed to the public safety concern of cannabis-impaired driving that emerged following legalization. He conversely said that he was not surprised by the results.
“Just because cannabis is legal and more people are consuming it doesn’t mean significantly more people will be driving impaired,” Macdonald said.
“There’s this assumption that an increase in marijuana use could have similar effects in drivers as alcohol impairment,” Vancouver cannabis rights activist Jodie Emery, and co-owner of downtown Vancouver’s Cannabis Culture shop, told the Vancouver Sun. “The federal government has paid for advertising campaigns that show a person’s dog talking to them after they’ve consumed cannabis.”
Emery continues to say, as a regular user, the government’s message about the effects of cannabis seem misleading, pushing for more honest, scientifically-driven cannabis information, “because aside from the propaganda, driving impaired on any drug or alcohol can have serious consequences.”
Macdonald mirrored the sentiment, that driving impaired on cannabis is a safety risk, though being stoned on cannabis is a very different experience than being impaired by alcohol, saying that being drunk is more dangerous.
“People who are stoned can have memory issues and divided attention, making it difficult for them to do two things at once, but being drunk affects a person’s actual psychomotor performance and can lead people to drive more recklessly,” Macdonald said.
Callaghan and his team will move forward to facilitate a followup study to further examine the Canadian impacts of cannabis legalization on driving-related fatalities.
