No, Smoking Marijuana Doesn't Make You More Likely to Crash Your Car

A man in a black jacket and sunglasses with his arm leaned against the car seat, smoking marijuana i...

After Colorado and Washington state voted to legalize recreational marijuana in 2013, the legislation's opponents and health officials conjured up the specter of stoned drivers turning America's highways into death traps. They warned that increased pot use related to decriminalization would lead to an increase in traffic fatalities due to "drugged driving." 

According to a massive new study from the government's safety body, they were wrong.

While the researchers found that 25% of marijuana users were more likely to crash than non-users (marijuana does impair your attention, after all), the researchers concluded that demographic differences like gender and age were far more compelling factors in explaining marijuana-related crashes: Younger drivers had a higher crash rate than older ones, and men crashed more than women.

"This study of crash risk found a statistically significant increase in unadjusted crash risk for drivers who tested positive for use of illegal drugs (1.21 times), and THC specifically (1.25 times)," explain researchers Richard P. Compton and Amy Berning. "However, analyses incorporating adjustments for age, gender, ethnicity and alcohol concentration level did not show a significant increase in levels of crash risk associated with the presence of drugs. This finding indicates that these other variables (age, gender ethnicity and alcohol use) were highly correlated with drug use and account for much of the increased risk associated with the use of illegal drugs and with THC."

"Drivers should never get behind the wheel impaired, and we know that marijuana impairs judgment, reaction times and awareness," said Jeff Michael, NHTSA's associate administrator for research and program development, in a statement. "These findings highlight the importance of research to better understand how marijuana use affects drivers so states and communities can craft the best safety policies."

Why it matters: When taken together, the NHTSA data effectively debunks one of the biggest myths about marijuana legalization: that an influx of legal weed will lead to legions of high motorists careening across the freeway in search of Funyuns and Mountain Dew. But while this research may be reassuring to budding potheads across the country, we certainly need more research: After all, recreational marijuana has only been legal in Colorado for just under a year.