With 4/20 rapidly approaching, AAA is issuing a warning about the dangers of driving impaired. New AAA research suggests that users of both alcohol and marijuana (not necessarily at the same time) are often some of the most dangerous drivers on the road. According to the research, drivers who consumed marijuana and alcohol within a 30 day period were more likely to engage in risky behavior like speeding, texting, intentionally running red lights, and aggressive driving.

"Regardless of whether marijuana is legal or prescribed, driving under the influence of the drug is illegal and extremely dangerous,” said Megan Cooper, spokeswoman, AAA – The Auto Club Group. “Although some drivers think marijuana makes them a better driver, research shows it can inhibit concentration, slow reaction times, and cloud judgment. That judgement is even more compromised by a marijuana user who also drinks alcohol. It’s important that drivers know the risk that comes with these two drugs and never drive impaired.”

The AAA Foundation for Traffic Safety's annual Traffic Safety Culture Index found that drivers who use both marijuana and alcohol were significantly more prone to driving under the influence of alcohol (Table 1) versus those who only drink alcohol but do not use marijuana. These motorists identified as someone who consumed alcohol and used marijuana in the past 30 days, and in some cases, they may have used both at the same time. They also engage in various other dangerous driving behaviors far more than drivers who consume either just alcohol or abstain from either drinking alcohol or using marijuana.

Driving Habits of Marijuana and Alcohol Users vs. Users of Alcohol only

Compared to alcohol-only users, drivers who admitted to using both drugs were more likely to report such behaviors as:

- Speeding on residential streets (55%) vs. alcohol-only (35%)

- Aggressive driving (52%) vs. alcohol-only (28%)

- Intentional red-light running (48%) vs alcohol-only (32%)

- Texting while driving (40%) vs. alcohol-only (21%)

Unsurprisingly, the study found drivers who neither drink alcohol nor use marijuana were considerably less likely to engage in the sorts of risky driving behaviors examined. This Foundation research was published in January 2021 in the peer-reviewed journal Transportation Research Record. 

Drug Use by the Numbers

Previous research suggests that users who drive high are at least twice as likely to be involved in a crash.

According to government data, alcohol and marijuana are the most widely used drugs in the United States - 139.8 million people aged 12 or older reported drinking alcohol in the past month, and 43.5 million reported using marijuana in the past year.  As of today, 16 states and Washington, D.C., have legalized marijuana for recreational use. And in 2021, 15 state legislatures are considering medical or adult-use marijuana legalization bills.

AAA is committed to educating the public about the dangers of substance-impaired driving. Through AAA Foundation research, AAA is working to improve understanding of the topic and work collaboratively with safety stakeholders to reduce the impact of substance-impaired driving-related crashes.