A study by a Northern Medical Program professor found that the legalization of cannabis in 2018 hasn’t resulted in an increase in traffic injuries.
Dr. Russ Callaghan looked at data from Alberta and Ontario emergency departments from April 1, 2015 to Dec. 31, 2019, and found that in the years immediately following cannabis legalization there of was no evidence of significant changes in traffic injury visits. Callaghan and his team used Alberta and Ontario data, because those are the only two provinces which report out all emergency department visits.
“Implementation of cannabis legalization has raised a common concern that such legislation might increase traffic-related harms, especially among youth,” Callaghan said in a press release. “Our results, however, show no evidence that legalization was associated with significant changes in emergency department traffic-injury presentations.”
Callaghan’s team looked at data for all drivers, as well as for youth – defined as individuals aged 14 to 17 in Alberta and 16 to 18 years old in Ontario – and found no increase in traffic-related injuries.
“Our findings are somewhat surprising,” Callaghan said. “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.”
It's possible the results were because of new federal legislation imposing more severe penalties for impaired driving due to cannabis and alcohol use, he said.
The project included researches from UNBC, the Centre for Addiction and Mental Health (CAMH) in Toronto, University of Victoria and Dalhousie University. It was part of Callaghan’s ongoing research into the potential harms and benefits of cannabis legalization.
Callaghan and the team are conducting a follow-up study to look at the impact on cannabis legalization on traffic fatalities in Canada from 2010 to 2020, which they hope to publish in 2022.
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. The results of this follow-up study should be available in the summer of 2022.
The study was supported in part by a Canadian Institutes of Health Research Catalyst Grant (Cannabis Research in Urgent Priority Areas).