科学美国人60秒:Traffic Deaths Increase after 4:20 P.M. on 4/20

Tomorrow is April 20th—4/20. It’s sometimes called a “High Holiday”. Because for a lot of people, 4/20 is Marijuana Day. And for them it’s kind of a tradition to start lighting up at 4:20 P.M. on 4/20. Which led a couple of researchers in Canada to wonder if there was any evidence for an increase in traffic deaths related to the occasion.

They got access to the United States National Highway Traffic Safety Administration’s Fatality Analysis Reporting System. Which tracks all public road accidents in which at least one person died. And they looked at the numbers on 4/20 from 4:20 P.M. through midnight. From 1992 through 2016. They also examined traffic deaths related to accidents on the day one week earlier and the day one week later during the same hours.

The result: a 12 percent increase in fatalities related to traffic accidents on 4/20 after 4:20 P.M. compared with the control dates. And for drivers 20 and under the figure was much higher, more than a 30 percent increase in some states. The research is in the journal JAMA Internal Medicine. [John A. Staples and Donald A. Redelmeier, The April 20 Cannabis Celebration and Fatal Traffic Crashes in the United States]

Of course, this study does not prove that impaired driving caused by marijuana consumption was the cause of the higher death rate. For example, could be that drivers crashed while simply trying to light up.

Scientific American has long supported making it easier for researchers to study marijuana’s medicinal effects as well as decriminalization in general. But we’re still against driving while intoxicated—so if you’re gonna be toking, keep those pistons from stroking. The pistons in the engine. Of the car. Just don’t drive.

—Steve Mirsky