Debate growing over drivers high on marijuana

As marijuana legalization looms, experts are trying to figure out how to deal with stoned drivers. File / Getty Images

As the federal government moves closer to legalizing the use of recreational marijuana, the debate is intensifying over the impact of driving while stoned.

One of Canada’s leading automotive journalists is suggesting the issue may be overblown.

David Booth, senior writer for Postmedia Driving, says he has not been able to find one study that definitively says the use of marijuana will increase the number of serious traffic accidents or fatalities.

LISTEN: Auto writer David Booth joins the Bill Kelly Show

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READ MORE: Simple roadside tests can identify pot-impaired drivers, study shows

He says he has looked at more than 20 scientific tests that included simulations and not one showed that drivers were unable to perform basic tasks behind the wheel.

In fact, Booth says the studies show that even “during emergency manoeuvres, there was no downside.”

He says the studies also suggest that if there was “any reduction of capabilities behind the wheel, that was more than compensated on how cautious people get.”

READ MORE: Bill Blair calls Marc Emery’s claim that pot makes people better drivers ‘complete nonsense’

He says unlike alcohol, which tends to make people more aggressive, pot tends to make people more subdued.

Booth also points to a study commissioned by the American Automobile Association Foundation for Traffic Safety that determined it’s not possible to determine whether a driver is impaired based on the amount of THC in the body.

“A quantitative threshold for per se laws for THC following cannabis use cannot be scientifically supported,” the organization found

In that same study, however, a sample of drivers arrested for marijuana impairment showed poorer performance in psycho-physical tests, such as standing on one leg, than a control group.

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READ MORE: Don’t legalize pot before figuring out how to deal with stoned drivers: poll

The same organization has also found that the number of fatal crashes involving drivers who tested positive for THC in Washington state in 2014 had roughly doubled when compared to the 2010 to 2013 figures.

Recreational marijuana use was legalized in the state at the end of 2012.

There’s more real-world evidence that driving while stoned increases crash risk. A systematic review of studies on cannabis and driving published in the British Medical Journal in 2012 pegged the risk of a collision causing serious injury or death at nearly double that of a sober driver.

As for minor collisions, the study determined the relationship “remains unclear.”

Further, the authors note that studies that use simulated conditions to measure the relationship between pot consumption and driving “generally focus on experienced cannabis users consuming the drug in unorthodox surroundings”  and that participants are “undertaking tasks that do not always reflect the complex nature of driving in natural settings.”

WATCH: MP and former Toronto police chief Bill Blair responds to Marc Emery’s comments about the apparent benefits of driving high

Click to play video: 'Are you a better driver if you’re high?' Are you a better driver if you’re high?
Are you a better driver if you’re high? – Apr 18, 2017

Booth’s comments come after former Toronto police chief and federal marijuana point man Bill Blair told Global’s The Morning Show Tuesday that studies have proven that marijuana impairs decision making, cognitive ability, memory and psycho-motor skills.

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“A recent Canadian study indicated that it increases the likelihood of being involved in an accident four-fold,” Blair explained. “It clearly impairs a person’s ability to operate a motor vehicle in a different way than alcohol, but definitely the science is unequivocal and clear.”

Blair was responding to a claim by marijuana advocate Marc Emery that habitual pot smoking improves your driving skills.

“Marijuana makes you more self-aware of your situation, so you’ll be a better driver if you smoke pot regularly,” Emery said on The Morning Show on Monday.

With files from Kerri Breen

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