U of Sask. study to give people weed gummies and a driver's test to measure impairment
Participants to get high and get tested on a state-of-the-art driving simulator
When it comes to human experiments, it'll be tough to find a more chill way to advance scientific knowledge.
Starting in early 2025, the Driving Research and Simulation Laboratory at the University of Saskatchewan will run a study using a state-of-the-art driver simulator to test how high people get after consuming edible cannabis.
"There's a lot of research on smoked cannabis and the impacts on driving, but very little on the effects of edibles," said Alexander Crizzle, the lab's director and an associate professor of public health.
People chosen for the study will eat a 10-milligram cannabis gummy with THC – the psychoactive compound that produces a high – and spend the day in Crizzle's lab getting tested on the driving simulator. Snacks and cab fare home are provided.
Crizzle and his research team will then measure impairment by testing participants on basic driving manoeuvres such as lane changes and merges.
"We also have a battery of tests where we can look at how people think and we kind of stress them out a little bit to see how well they perform under a certain amount of stress," Crizzle said. "That kind of gives us a good indication of how much the edibles are impacting their ability to think and drive."
The Driving Research and Simulation Laboratory has run studies examining health and safety aspects of long-haul trucking (its second simulator is a larger model with an 18-gear stick shift) and drivers with early onset dementia. The lab even studied the driving simulator itself by testing if training on it can reduce crash risks among young drivers.
The lab's track record and access to the specialized car simulator, which has multiple monitors for a 180-degree view and a motion platform to mimic an actual driving experience, prompted CAA Saskatchewan to connect with Crizzle to develop the project.
CAA Saskatchewan spokesperson Lona Gervais said the auto club is co-funding the study and plans to use the results in a future national campaign.
"There was a CAA poll that showed that young drivers think that they can drive just as good or better when they're high, and that's increased by 10 per cent since 2021," Gervais said.
"So there's a real need for research and we know that young Canadians are consuming more cannabis edibles. And so this lack of awareness can be a real danger on our roads."
When Ottawa legalized possession of cannabis in 2018, it also created new criminal offences related to driving while impaired. Saskatchewan has a zero tolerance policy and drivers get an immediate licence suspension for failing a roadside saliva test for THC.
In 2023, 1,594 people drivers in Saskatchewan had their vehicles impounded and licences suspended for three days for having THC in their system. In 2019, it was just 76.
Crizzle said this study is the first of its kind. There isn't much research about edible cannabis, and there isn't any on edibles and driving ability. The study will also compare the different effects of indica and sativa, the two main strains of cannabis.
"We know studies say the effects [of edibles] will last up to 10 hours, but we really don't have any clue what that means for driving impairment," Crizzle said.
"Even if the effects taper off the 10th hour, you could be unsafe. But we don't know. So we test at four intervals. We kind of hope to see some data as to when impairment is most heightened."
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