Article content continued

Among frequent users of marijuana (more than once a week) in the study, 80 per cent of males and 75 per cent of females acknowledged they had, in the past month, been in a car driven by someone (including themselves) who had used marijuana or other drugs. Sixty-four per cent of frequent-using males and 33 per cent of females reported they were “intoxicated” with marijuana while driving, riding a motorcycle, boating or using machinery.

And half of the pot frequent-user males (42 per cent of females) said they’d been in a car with a driver who had used alcohol. Of occasional users (once a week at most), 28 per cent said they’d been in a car, in the past month, with a driver (including themselves) who had used alcohol.

“Epidemiological studies suggest that acute marijuana use approximately doubles the rate of crashing,” the study says, while allowing that the finding hasn’t been shown in all studies.

As Canada moves toward decriminalization, Leadbeater said governments must direct funding to education “that presents an accurate picture of potential harms.”

Research on marijuana and driving risks is critically important because youth are already vulnerable to not only being in crashes more than experienced drivers, but also more likely to be involved in fatal crashes as passengers. Consumption of marijuana exacerbates the risk for young drivers and their passengers, with or without concurrent use of alcohol, she said.