Car Insurance Report Finds Cannabis Reforms Not Associated With More Traffic Accidents

A report published earlier this month by the Canadian Institute of Actuaries (CIA) and Casualty Actuarial Society (CAS) which analyzes the impact of cannabis law reforms on vehicular accidents in Canada and the U.S. found no statistically significant impacts of decriminalizing cannabis.

The report, Assessing the Impact of Marijuana Decriminalization on Vehicle Accident Experience, uses insurance statistics to paint a picture of traffic accident variations in Canada following the nation’s 2018 cannabis legalization policy, finding no significant changes. The report also estimated the state-wide effects of state-level legalization laws in the U.S., which likewise showed no consistent or significant results to support the conclusion that the reforms led to increased road fatalities or accidents.

“The literature review shows that while marijuana impairment affects driving behaviour, the behaviour is not always riskier; for example, slower speeds and longer following distances of impaired drivers have been reported. The observational studies of road accidents report mixed results, most often not detecting significant effects, particularly in the long term.” — Excerpt from the report’s Executive summary

Researchers used data-driven methodologies to overcome the limitations of previous research, according to a press release.

“The methods used in this research include improved statistical models, machine learning and other data science techniques. The models used high-resolution weather data to account for the effects of weather factors,” said the report’s author Dr. Vyacheslav Lyubchich.

The research said that inclement weather and temporal patterns of human activity (such as cycles of yearly, weekly, and daily driving habits) would serve as better predictors of the vehicle accident experience.