Neither Ontario nor Alberta — far and away, the leaders for the number of cannabis stores in the country — have witnessed a significant rise in emergency visits from traffic-related injuries since weed got the green light three years ago.

“There was no evidence of significant changes associated with cannabis legalization on post-legalization weekly counts of drivers’ traffic-injury ED visits,” researchers write.

Comparing the pre- and post-legalization periods, they specifically found that the number of weekly traffic-injury ED visits in Alberta was up by just 9.17 among all drivers and down by 0.66 visits among the young driver group.

Research involving driving and cannabis is receiving increasing attention of late. Australian researchers recently concluded “road safety risks associated with medicinal cannabis appear similar or lower than numerous other potentially impairing prescription medications.”

And another Australian study suggested that using CBD does not impair driving performance and consuming moderate amounts of THC produces only mild impairment lasting up to four hours.

Still, Canadian students with more relaxed views of weed appear to be more likely to consume and drive than others in their age group. Indeed, slightly more than 10 per cent of Ontario high school-aged drivers admitted to having driven within an hour after using weed in the last year.

Another recently published Canadian study exploring ED visits — albeit related to weed intoxication at a single ED in Hamilton, Ont. — found treatment for acute cannabis intoxication was up among 18- to 29-year-olds, but not overall.

Those numbers differ considerably from a U.S. study out of Colorado, where adult-use cannabis has been legal since 2014. The Associated Press reported in March 2019 that weed-related ED visits to a Denver hospital witnessed a three-fold increase pre- and post-legalization. Investigators in that research pointed to inhaled cannabis and marijuana-infused edibles as the two main culprits for symptoms ranging from vomiting to racing hearts.