MUHC study finds cannabis use increases risk of car crash for up to five hours

October 22, 2018

A study conducted by the Research Institute of the MUHC (McGill University Health Centre) and funded by the Canadian Automobile Association, determined that drivers who use cannabis are more likely to get into a crash.

The study involved 45 people under the age of 25 who took part in driving simulation tests before and after getting high.

The result was that people were more likely to crash after using marijuana, whether tested one, three, or five hours after they used cannabis.

Subjects felt less confident about their driving skills and drove more cautiously after using marijuana, but still failed routine driving tasks, driving through intersections, changing lanes and avoiding pedestrians for at least five hours after use.

Police will be using a combination of saliva, blood, and urine tests, in addition to field sobriety checks to determine if drivers are impaired. Quebec has a zero-tolerance law regarding cannabis use and driving.