A new study from the National Highway Traffic Safety Administration (NHTSA) has found that consuming cannabis does not elevate a driver’s crash risk, a result that’s directly contrary to prohibitionist arguments that increased access to cannabis will lead to further car accidents.
The study looked at over 3,000 drivers involved in a car accident over a 20-month period, and measured which substances (if any) were in their system at the time of the accident. The study also included data from 6,000 control drivers who were not involved in any accidents.
“[This study] was the most closely controlled study of its kind that has ever been conducted,” says Gordon Trowbridge, Communications Director for the NHTSA.
Unsurprisingly, the study found that although cannabis use had little effect on a person’s crash risk, drivers with alcohol in their systems were far more likely to be involved in a crash. Adjusted for age and gender, the study found a driver with a blood alcohol content of .08 is four times as likely to be involved in an accident than if they had no alcohol in their system. When BAC hits .15, drivers are 12 times more likely to get into an accident.
According to Trownbridge, the NHTSA is currently working on a separate study alongside the state of Washington to understand the effect of legalization on traffic safety.