On October 17, 2018, cannabis sale and use became legal across Canada in a regulated market. To prepare for this, new federal legislation passed in June 2018 to deter and detect those who drive while impaired, by alcohol, cannabis, or other drugs.

There are three new offences of having prohibited blood drug concentrations within two hours of driving. There is a straight summary conviction offence and two hybrid offences; one hybrid offence applies to drugs alone, the other applies to drugs in combination with alcohol. There is no legal exemption for medical users of marijuana.

  • A summary conviction where a driver has at least 2 nanograms (ng) but less than 5 ng of THC per mL of blood within two hours of driving;
  • A hybrid offence where a driver has at least 5 ng or more of THC per mL of blood; and
  • A hybrid offence where a driver has a combined Blood Alcohol Content of 50 mg of alcohol per 100 mL of blood (0.05 BAC), combined with a THC level equal to or exceeding 2.5 ng per mL of blood within two hours.

Impaired driving is the leading criminal cause of death and injury in Canada, and drug-impaired driving is increasing. The number of Canadian drivers killed in vehicle crashes who tested positive for drugs (40%) now exceeds the number who tested positive for alcohol (33%). Lawyers who represent plaintiffs injured by a drug-impaired driver need to be aware of these heightened risks.

Unlike alcohol consumption, there is no “safe period” after toking that reliably reduces impairment. Some sources suggest 6 hours would suffice for a standard joint, but impairment varies by the individual user depending on:

  • Body type;
  • How cannabis was consumed (smoked, inhaled, ingested);
  • The quantity consumed ;
  • The variety of cannabis and its THC levels, including cannabis prescribed for medical use.

Impairment tests include the existing Standard Field Sobriety Testing and the newer Drug Recognition Expert Evaluation, conducted by a trained officer. THC specifically is detected using an oral fluid “spit test”. THC can also be detected using blood tests. There is still some debate about the accuracy of these tests; THC can be present for a very long period, casting doubt on whether a driver was impaired before the accident. Again, plaintiffs’ lawyers need to be aware of these nuances.

In Ontario, there is zero tolerance for young, novice or commercial drivers:

  • Under 21 years of age
  • With a G1, G2, M1 or M2 licence
  • Driving a vehicle that requires an A-F driver’s licence or Commercial Vehicle Operator’s Registration
  • Driving a road-building machine

Medical cannabis users in Ontario are not subject to the zero tolerance requirements but may still face penalties and criminal charges if the ability to drive has been impaired.

In British Columbia, a law passed in March 2019 includes a 90-day driving ban on anyone caught driving while drug-impaired. Like Ontario, there are zero-tolerance restrictions for drivers in the graduated licensing program. Similar to alcohol, marijuana is not allowed within a driver’s reach.

As a result of all these factors, auto insurance rates across Canada might increase. Certainly, people driving under the influence will see rates increased or policies cancelled. But rates for all drivers could increase if cannabis legalization results in more motor vehicle accidents, as happened in Colorado, where cannabis was legalized in 2014. Auto insurance premiums in Colorado jumped by 54% between 2011 and 2017 because the state saw an increase in accidents in that period. According to the Insurance Bureau of Canada there was a direct correlation in the increase in traffic accidents and fatalities involving cannabis-impaired drivers. But a University of British Columbia study of Colorado and Washington – the two US states that legalized recreational marijuana – did not see any significant change in accident rates compared to other states.