According to a new study conducted by Dr. Russ Callaghan, a Professor at the UBC Northern Medical Program, the legalization of cannabis in Canada in 2018 was not associated with an increase in traffic injuries. Dr. Callaghan and his team studied weekly provincial counts of traffic-injury emergency department (ED) presentations of drivers, including youth drivers, in Alberta and Ontario. These two provinces were chosen as they were the only ones that captured all ED visits occurring in the general population. Youth was defined as individuals aged 14-17 years in Alberta and 16-18 in Ontario. The study reviewed all Ontario and Alberta emergency department data from April 1, 2015 to Dec. 31, 2019. The team found that there was no evidence of any significant changes in traffic-injury emergency department visits among all drivers or youth drivers after the legalization of cannabis.

Dr. Callaghan said that the implementation of cannabis legalization has raised a common concern that such legislation might increase traffic-related harms, especially among youth. However, their results showed no evidence of this being the case. “Our findings are somewhat surprising,” said Dr. Callaghan. “I predicted that legalization would increase cannabis use and cannabis-impaired driving in the population, and that this pattern would lead to increases in traffic-injury presentations to emergency departments.” He went on to say that it is possible that the results of the study could be due to the deterrent effects of stricter federal legislation, such as Bill C-46, which came into force shortly after cannabis legalization. These new traffic-safety laws imposed more severe penalties for impaired driving due to cannabis, alcohol, and combined cannabis and alcohol use.

The study was supported by a Canadian Institutes of Health Research Catalyst Grant (Cannabis Research in Urgent Priority Areas) and was conducted by researchers from UNBC, the Centre for Addiction and Mental Health (CAMH) in Toronto, University of Victoria, and Dalhousie University. Dr. Callaghan and his team are currently conducting a follow-up study to examine the impacts of cannabis legalization on traffic fatalities in Canada from 2010-2020, with results expected to be available in the summer of 2022. The study was recently published in Drug and Alcohol Dependence, an international peer-reviewed scientific journal.