A Winnipeg man says police temporarily suspended his licence for driving while high even though he was not under the influence, and is arguing the test used by officers wasn’t accurate.
Sean Vipond, 30, said he was one of the 97 people who were issued roadside licence suspensions earlier this year as part of an enforcement campaign because they tested positive for cannabis consumption — but he maintains he wasn’t under the influence.
He was pulled over in mid-February, after he had just stopped by a local dispensary to buy vape pen cartridges and was on his way to pick up his wife from work, he told CBC.
Vipond said it had been at least 20 hours since he’d last consumed cannabis, but still tested positive for the drug after police performed an oral fluid test, swabbing his mouth.
“[Police] told me to my face that there was no visible reason for suspicion. It was just purely on the basis of I had bought weed and then drove,” Vipond said, adding he was frustrated after police announced the stats from their enforcement campaign last month.
“To see [Winnipeg police] boasting about this and acting like everybody who was caught was … recklessly smoking during the day and driving high, when that’s really not the reality of it — it’s humiliating.”
Winnipeg police said in an email officers use drug screening equipment as approved by the Criminal Code, and that testing positive on such equipment results in an administrative licence suspension in Manitoba.
Last month, police said 47 per cent of 207 drivers who were tested for drugs using approved screening between January and March as part of this year’s “Don’t Drive High” campaign tested positive for cannabis consumption.
The oral swab test is intended to determine whether a driver’s saliva has traces of tetrahydrocannabinol (THC), the main psychoactive component in cannabis.
But experts say while those tests can detect cannabis in the system, they’re not suited to prove intoxication by themselves.
They said that unlike with alcohol blood levels, THC levels are not an effective proof of impairment.
THC is a lipid that’s “slowly released from our bodies in normal metabolic processes over time,” said Robert Laprairie, an associate professor with the University of Saskatchewan’s college of pharmacy and nutrition.
“What that means functionally, though, is that your rate of release, or rate of getting rid of THC, is going to depend on things like your overall body fat content, your body composition, your sex, your gender, your weight, and how often or how regularly you use THC.”
That means that while a test may show a person has THC in their system, they may not necessarily be impaired, he said.
Laprairie’s research specializes in cannabis, and he’s done work exploring the effects the drug has on the body.
He said that he’s personally seen people process THC in as little as two hours, while for others, it can take up to 36 hours.
“As a researcher, I think more research is needed. I think that we need better tools to understand impairment in terms of what would be impairing in THC use or cannabis use.”
Dr. Jeff Brubacher, an associate professor at the University of British Columbia whose research specializes in impaired driving, said even federal laws — which set penalties for drivers with two to five nanograms of THC per millilitre of blood, and harsher penalties for those who go over that — aren’t reliable benchmarks.
He said the most effective way to check for impairment may be having a drug recognition expert perform a behavioural test.
“But that’s complicated, right? It takes special training and it takes several hours to do that test, so it’s not readily available,” he said.
Brubacher did research on drivers taken for treatment after accidents that showed 3.2 per cent of injured Canadian drivers who had their blood samples collected between 2018 and 2023 had high THC levels (above five nanograms per millilitre). That’s compared to 12.2 per cent who had high alcohol levels.
Testing for THC is “a tool in their toolbox” for police, he said. But “before they can demand a saliva sample, [police] need evidence that the person is impaired. And if they don’t have that evidence, they shouldn’t be using it.”
Vipond said when he was pulled over, he offered to show police the cannabis products he’d purchased, to prove they were still sealed.
Police suspended his licence for three days and confiscated it, which Vipond said left him and his wife with no way to get around the city. He also had to pay a $50 fee for recalculating his driver safety rating when he went to renew it.
“If you consume regularly, you simply will not pass that test, no matter how careful you’re being,” he said. “They’re using inaccurate tools and they’re being allowed to treat them as if they’re far more accurate than they are.”
