Over the past month nearly 15 million people have driven a car within an hour of using marijuana, according to a survey released recently by AAA Foundation for Traffic Safety.

Effects from marijuana can be experienced anywhere from one to four hours after usage. Those under the influence of the drug are twice as likely to be in car crash, the survey said.

Yet, 70% of Americans believe they’re unlikely to get caught by law enforcement while driving high, the survey found.

Tom Woodward, coordinator of Maryland’s drug recognition expert program, said it’s just as dangerous to drive under the influence of marijuana as alcohol or other drugs, such as opioids, even though the impairments are not the same.

“We do know that marijuana certainly does cause impairment,” Woodward said. “But because it’s different than alcohol, people don’t view it as being bad.”

The AAA survey found 7% of Americans said they approved of driving under the influence of marijuana. More than any other age group, millennials are most likely to drive under the influence of marijuana at 14%, followed by Generation Z at 10%. Men are more likely than women to drive after using the drug.


But the idea that people find it acceptable to drive while high on marijuana did not surprise Woodward. He related it back to educating people about the dangers of driving drunk, which began nearly 40 years ago. He hopes it won’t take as long this time.

“People used to think they couldn’t get caught for driving under the influence of alcohol either until public information campaigns,” Woodward said. “But that perception has changed. And I think it can change with marijuana, too.”

Maryland has seen a steady climb since 2012 in the number of drivers found under the influence of cannabis and the number of related crashes, according to state data. From 2017 to 2018, marijuana-related crashes nearly doubled from 34 to 60. That means cannabis accounted for 32% of all drug-related crashes last year.

Woodward said he is working with the Maryland Highway Safety Office to create campaigns around marijuana and the dangers of driving after using the drug. Additionally, he said his office and law enforcement statewide have increased training for officers to detect those behind the wheel who are under the influence.

Officers use clues such as the inability to cross eyes, swaying or having a driver touch their finger to their nose to try to determine whether they are under the influence of marijuana. It’s different from tests that might be used when alcohol is involved because someone’s balance won’t change as much with marijuana, Woodward said.