Research Shows Increase in Impaired Driving After Cannabis Legalization

Driving while high on marijuana has become more “common” among Canadians since the substance became legal in 2018, according to recent in-house federal research.

“There is also widespread agreement it is more common than alcohol-impaired driving. While driving impaired was not condoned, participants typically believed cannabis does not have the same impact.”

The January 2024 research by the Department of Health found that risk perception concerning cannabis dependence was low among users, with many saying they are not dependent on the drug and could stop using it at any time. Those who felt they were dependent on marijuana said they didn’t have any concerns with it.

Users said there was “widespread agreement” that driving while under the influence of cannabis is common in their communities and among their friends and family circles. While they did not condone this, they also typically believed that cannabis did not have the same impact on the body as alcohol, according to the survey.

“As well, there was some reluctance to believe that cannabis use equates to cannabis impairment,” the report stated, adding that many said the risks of driving after consuming marijuana depended on factors such as the amount of time elapsed between consuming it and driving, as well as tolerance to the drug.

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Participants shared that legalization made cannabis products more readily accessible and instilled a sense that cannabis can be consumed safely,” said the report. “Participants also felt legalization increased social acceptance of its use.”

Frequent and prolonged consumption of cannabis has been associated with mental health problems such as anxiety and mood disorders, neurocognitive impairment, and cardiovascular and respiratory diseases, the report said.

Rates of daily use of the drug are “high” in Canada, researchers said, referencing the 2023 Canadian Cannabis Survey that found 25 percent of Canadians who reported using cannabis in the last year further reported daily or near-daily use.

The rate of drug-impaired driving offences increased by 105 percent from 2017 to 2020, rising from nine offences per 100,000 to 19 per 100,000, according to Statistics Canada.

Parliament passed Bill C-46—An Act To Amend The Criminal Code—that allowed random roadside drug testing last spring and it was made law in May of 2023.