Virginia, United States — One in thirty of all American drivers in an Insurance Institute for Highway Safety (IIHS) survey admitted to using alcohol and marijuana within two hours of driving.
One in ten drivers reported using alcohol and marijuana at the same time in the past year, compared to the seven in ten who drove drunk.
According to the IIHS, this combination results in more dangerous driving than just using a single substance—incredibly dangerous, considering that 30 percent of American traffic deaths in 2021 were influenced by drunk driving, according to the institute.
While Canadian data does not specify how many drivers used alcohol and drugs simultaneously before getting behind the wheel, more than a quarter of cannabis users have used a vehicle while under the influence in 2021, similar to reported levels in 2020 (26 percent) and 2017 (28 percent).
Among Canadian drivers killed in crashes, more drivers test positive for drugs than alcohol according to the federal government. This can be explained by the availability of harm-reduction advice regarding alcohol, compared to the relative absence of such advice for marijuana.
Effectively, there is no equivalent to waiting an hour per drink before driving when it comes to marijuana. Unlike alcohol, there are unclear guidelines on how much cannabis can be consumed before it is unsafe to drive, or how long a driver should wait after consuming cannabis.
Under the Criminal Code of Canada, drivers will face penalties if their blood tests show more than two nanograms of THC per millilitre of blood—the chemical responsible for altering the user’s state of mind.