In recent years, 32% of fatal car crashes were caused by drunk driving, while 31% were caused by speeding, 16% by distracted driving, and 11% by weather conditions. However, those trends seem to be seeing a shift as legal marijuana comes into play.
In Colorado alone, 77 citizens died in marijuana-involved car accidents in 2016, the most recent year tracked by the state. This is a dramatic increase since 2013, according to the Denver Post. People who use marijuana less than once a week may be impaired for a least six hours after smoking and eight hours after eating or drinking marijuana products, so impaired driving is likely to happen.
Colorado isn’t the only one seeing an increase in these marijuana-related crashes. According to the New York Times, 25 years of research has shown that April 20, the day known for marijuana celebration, sees more of these car crashes than any other day. A study by JAMA Internal Medicine looked at car crashes in the United States in which at least one person died. They compared the number of fatal crashes between 4:20 PM (the traditional start of pot celebration on 4/20), and midnight on April 20 each year with accidents during the same one week before and one week after April 20.
There was no difference before 4:20 PM, but there was a 12% increased risk of fatal car crashes on April 20 compared to the control dates from 4:20 PM to midnight. The increased risk was primarily among drivers aged 20 and younger.
The Washington Post also looked at the numbers. For the first half of 2017, pedestrian fatalities increased greatest in states that had previously voted to legalize the recreational use of marijuana.
Dr, Donald A. Redelmeier, a professor of medicine at the University of Toronto, said, “These crashes really don’t have to happen. In the Netherlands, they’ve had legalized marijuana for years, but they have many more interventions — speed cameras, radar, sobriety checkpoints. The roads in the Netherlands are now much safer than those in the U.S.”