Being stoned behind the wheel is proving to be more dangerous than driving drunk, according to a new study examining the impact of marijuana legalization on traffic accidents in Canada.
Since Canada legalized recreational cannabis in 2018, documented marijuana-related traffic accidents requiring emergency room treatment have skyrocketed by 475% between 2010 and 2021. In contrast, car crashes due to drunk driving grew only 9.4% during the same period.
“The concern is that the increase in these rare but very severe traffic injuries are capturing broader trends of increasing cannabis-impaired driving over time and after legalization,” said study author Dr. Daniel Myran, assistant professor of family medicine at the University of Ottawa.
After Canadian legalization in 2018, the rate of emergency room visits due to marijuana-related car crashes initially spiked by 94%. As marijuana commercialization increased, these visits surged 233% compared to pre-legalization levels.
Over the past ten years, a growing number of states have legalized the use of cannabis for either medical or recreational purposes. While no long-term corresponding study like the one released in Canada has been issued in the United States, experts believe similar issues are common as more drivers take to the road under the influence of marijuana.
In the United States, the last National Highway Traffic Safety Administration (NHTSA) report from 2014 revealed a 48% increase in drivers testing positive for marijuana. An updated report from the NHTSA is expected in late 2024.
The 2016 Drug and Alcohol Crash Risk Study found marijuana to be the most frequently detected drug after alcohol, with users more likely to be involved in crashes.
Cannabis-related car crashes are notably severe. Nearly 90% of victims in marijuana-involved accidents arrived by ambulance, compared to 40% for accidents without alcohol or cannabis.
Hospital admission rates for marijuana users in car accidents were nearly 50%, while non-users stood at just over 6%. Intensive care admissions were also significantly higher, with 22% of stoned drivers requiring intensive care compared to less than 2% for other crashes.
The rise in cannabis potency is another concern. Stronger products increase impairment and risk. Combining cannabis with alcohol amplifies the impairing effects of both substances, making driving even more dangerous.
Unlike alcohol, where legal limits for driving are clearly defined, there are no such guidelines for cannabis in the U.S. Driving under the influence of marijuana is illegal at any level, similar to opioids or other impairing drugs.
Experts stress the importance of public education on the risks of driving while high.
“Education, education, education. The general public should be educated on the risks associated with cannabis, in particular in the younger strata of the population,” said Dr. Myran. He also advocated for explicit warnings on THC-containing products, similar to those on tobacco cigarettes.
As cannabis use becomes more widespread, much more is needed to curb the growing concern over driving under its influence. Awareness and education are key to preventing the dangerous consequences of impaired driving.
