How do THC gummies impact driving? Sask. researchers use simulator to find out

Researchers at the University of Saskatchewan are conducting a study to learn how THC edibles impact driving performance.

Participants will consume 10 milligrams of THC edibles before getting behind the wheel of a driving simulator.

"We're going to be the first to really dive into this topic," Alexander Crizzle, an associate professor who is leading the study, told CTV News.

"Most of the research right now is on inhaled cannabis or smoked cannabis. There hasn't been any studies looking at the effects of edibles."

Participants will take the simulated driving test four times: 1.5 hours, 2.5 hours, 4 hours, and 6 hours after consuming the edibles.

"Sometimes if people are taking edibles, they might feel like there's a window of safe time they have to drive," Crizzle said, at the simulation lab.

"We're trying to understand how quickly these edibles hit, how pronounced those effects might be and how long they last."

• Get the CTV News app for Saskatoon area breaking news alerts and top stories 

The study involves 50 participants and will examine the effects of both sativa and indica cannabis strains.

Before consuming the edibles, participants must take a drug test, pregnancy test and vision test.

Then, participants get into the simulator for a baseline assessment — to see how they drive under normal conditions.

"And then we give you some edibles, and we see how well you drive over those various time points," Crizzle explained.

A camera is set up on the simulator so Crizzle can monitor participants' eye movement.

Crizzle is also tracking driving speed, brake pressure and how well drivers stay in their lane.

The researchers can modify driving conditions and scenarios. Participants may drive on busy city streets or a rural highway in the middle of winter, with deer darting into traffic.

Unlike alcohol, which has a clear legal limit, cannabis impairment is difficult to quantify.

Crizzle hopes the findings from this research will impact sobriety testing.

"I think this has the potential to really inform policy, in terms of how we assess drivers," Crizzle said.

The study is scheduled to begin in January and conclude in April, with the results expected to be released in May.