NHTSA: Marijuana use may not significantly increase traffic accidents

WASHINGTON, Feb. 7 (UPI) -- A new study from the National Highway Traffic Safety Administration indicates marijuana use doesn't increase traffic accident risk as much as previously thought.

The study looked at 9,000 drivers over the course of 20 months. It found drivers who regularly use marijuana are 25 percent more likely to be involved in a traffic accident. However, when the researchers factored in age, gender and level of alcohol consumption among marijuana users, they found those factors were more significant than the use of marijuana. Marijuana use did not noticeably impact crash risk once the other factors were added.

"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," the study reads. "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."

The study indicates that drunk driving is still a major problem, more so than using marijuana, but it also found drunk driving has decreased in recent years.

"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," said Jeff Michael, NHTSA's associate administrator for research and program development.