Everyone knows that it’s dangerous to drive drunk, but the public discourse around driving stoned is a bit fuzzier. As cannabis transitions to mainstream acceptance in the U.S.

, the spotlight has often been on the benefits of legalization, and potential health upsides . What isn’t discussed as much is what happens when people smoke up and get behind the wheel—with catastrophic consequences. The National Transportation Safety Board (NTSB) issued a safety alert about the dangers of driving while stoned last month, after it concluded an investigation that found cannabis played a role in a 2022 car crash that killed six Oklahoma high school students.

“We found that there was widespread misconception about the impairing effects of cannabis,” NTSB Office of Highway Safety director Robert Molloy tells Fortune . “We recognized that teenagers are especially vulnerable to the risks associated with marijuana impaired driving due to their limited driving experience ..

. I think we also do a poor job of talking about the effects of marijuana on driving.” Several studies show that it’s unsafe to drive while high, revealing that cannabis significantly affects driver reaction time, decision making, and coordination.

And experts say that while messaging around drunk driving has been robust, the infrastructure and education around stoned driving still has a long way to go. What we know about driving while stoned The most comprehensive study ever done on driving-while-high leaves.