How Does Marijuana Use Impact Driving?

A new study from Harvard Medical School focused on the effects of marijuana use on someone driving a vehicle. Most people assume that driving high will impair your driving abilities, but this study took that hypothesis a step further and discovered that regular marijuana use makes you a worse driver even if you are not high when driving.

According to this report, chronic recreational marijuna use is directly connected to poorer driving performance in non-impaired individuals when compared with drivers who have never inhaled. The study found that regular marijuna users had more accidents, drove faster more often and ignored red lights more often than non-smokers.

The study went on to say that their research found the problem was exacerbated even more when the driver was linked to marijuana use starting before the age of 16.

Naturally, the rapid proliferation of recreational marijuana use throughout the United States becomes a bit more alarming if this findings of this study are true. Even marijuana supporters can agree that adding more impaired drivers to the road is never a good idea, no matter the reason for their impairment.

Senior author of the study Dr. Staci Gruber spoke with the Insurance Journal about the findings of this study. “People who use cannabis don’t necessarily assume that they may drive differently, even when they’re not high,” said Gruber. “We’re not suggesting that everyone who uses cannabis will demonstrate impaired driving, but it’s interesting that in a sample of non-intoxicated participants, there are still differences in those who use cannabis relative to those who don’t.”

This study focused specifically on recreational mairjuana use, not medical use. Now many people may think that the only difference between those two types of use comes from the law, but the truth is that the drug has different effects on different people. Gruber goes on to address this in more detail.

“It’s important to be mindful that whether someone is acutely intoxicated, or a heavy recreational cannabis user who’s not intoxicated, there may be an impact on driving, but certainly not everyone demonstrates impairment simply as a function of exposure to cannabis,” said Gruber. “This is especially important to keep in mind given increasing numbers of medical cannabis patients who differ from recreational users with regard to product choice and goal of use.”

One of the biggest implications of this study has nothing to do with driving, but more with how the public, and the lawmakers, define with “imparied” means. Traditionally, the definition has centered around being high or drunk at the same time you were driving. If more studies confirm Harvard’s finding, that definition could undergo a big change in the near future.

The report was published in the Drug and Alcohol Dependence journal under the title “Recreational Cannabis Use Impairs Driving Performance in the Absence of Acute Intoxication”. The study was authored by McLean Hospital’s Mary Kathryn Dahlgren, PhD, Staci Gruber, PhD, and their team from McLean’s Cognitive and Clinical Neuroimaging Core and the Marijuana Investigations for Neuroscientific Discovery (MIND) program.

The bottom line is to never drive under the influence of anything, and always have a proper car insurance policy in place in case someone doesn’t heed this advice. To learn more about your current policy, or to find out what your options for new policies are, reach out to TGS Insurance at


About Katie Rosario

Katie has been in the marketing industry for over 10 years and has a strong passion for writing great content. She has been writing for TGS Insurance for three years and strives to make every piece of content she works on informative and easy to read. In her spare time, she enjoys baking and spending time with her family.

Leave a Reply

Your email address will not be published. Required fields are marked *