Limits for drug-impaired driving set for Canada

Using even a little cannabis may push a user over the new legal limits, according to the National Post.
Using even a little cannabis may push a user over the new legal limits, according to the National Post.

Limits for drug-impaired driving set for Canada

With recreational cannabis set to be legal next month, new limits on the amount of THC (the main psychoactive component in cannabis) will also go into effect sometime in early 2019. Using even a little cannabis before driving could push a person’s THC level above these limits.

A “zero-tolerance” approach to drug-impaired driving

The federal government is “taking a zero-tolerance” approach to drivers’ cannabis use until research more clearly establishes the precise effects of cannabis on impairment.

It created “per se” limits for the amount of THC that can be in a driver’s bloodstream within two hours of driving a motor vehicle. They make the use of THC above these limits illegal, which allows police to lay impaired driving charges based solely on the results of roadside saliva tests.

The second quarterly Statistics Canada national cannabis survey, released in August 2018, seemingly supports the federal government’s caution. It found:

  • 14 per cent of cannabis users admitted they had driven their car within two hours of using cannabis at least once in the past three months.
  • 5 per cent of Canadians over 14 years of age had been a passenger in a vehicle driven by a person who had used cannabis within the previous two hours.

Andrew Murie, the chief executive officer of MADD Canada, finds these figures “alarming. I think if you compare it to alcohol, it’s shocking.” Murie explains it’s difficult to determine the general effect of cannabis use on people. This depends on the THC concentration in the cannabis a person uses as well as an individual’s tolerance level, which can both vary.

Still, MADD Canada recommends that no one should drive a vehicle if they have used any cannabis within the previous four hours.

THC limits in your blood

The government’s proposed levels of impairment are based on the amount of nanograms (ng) of THC per millilitre of blood a person has in their body. There are two new offences:

  • A driver with between two and five ng of THC in their blood will be a lower-level offence. The person can be fined up to $1000.
  • A driver with 5 or more ng of THC in their blood will face higher penalties with each repeated offence:
    • A first offence leads to a mandatory $1000 fine
    • A second offence carries a 30 day prison term
    • A third offence carries a 120 day prison term

A driver whose alcohol level is 0.05 mg per 100 mL and whose THC level is 2.5 ng or more will face the same penalties as a driver with a 5 ng level.

Legal challenges to the new THC limits

Defence lawyers will challenge these limits in court when the first charges are laid by police in 2019, so they may not be set in stone.

According to the National Post, the science supporting a link between cannabis use and impairment is also not as authoritative as the science connecting alcohol use to blood impairment. Defence lawyers will likely use this to argue that the limits are too low or should be eliminated altogether.

The new saliva-test roadside devices will also no doubt be challenged in court. While they work in other countries, they may have to be specially configured to meet Canada’s requirements.

Nor is it clear how well the devices work in cold weather. A pilot project in Saskatchewan and the Northwest Territories found that “there were some temperature-related issues when the devices were used in extreme cold temperatures.” Even if the test is done in the warmth of a police car, there are questions about whether the device has been affected by the cold.

Will drug-impaired driving decline?

The federal government will spend $62.5 million over the next five years to warn Canadians about drug-impaired driving and its consequences. Murie thinks the number of cannabis-impaired drivers will fall, although the amount and tests for the new limits will be challenged.

“I think once people get the idea that police do have the tools, that they can detect drug-impaired drivers, especially cannabis, then I think like alcohol with the breathalyzer it’ll start to lower those rates.”


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