Is driving while high on marijuana as dangerous as driving under the influence of alcohol? Obviously, how much alcohol or marijuana matters. A driver who has a .19 blood alcohol content (BAC) is almost certainly going to be a more dangerous driver than someone who took two hits of marijuana.
There are far fewer studies on the effects of driving under the influence of marijuana compared to the years of research on how alcohol affects a driver. Experts who study the impacts of driving while high are still sorting it out. One thing is clear: fatal vehicular accidents involving a driver under the influence of cannabis have increased, more than doubling from 2000-2018. In those years, fatal accidents involving a driver under the influence of marijuana went from 9% to 22%. The percentage of drunk driving fatalities during those years remained about same.
While marijuana-involved fatalities have increased, there is evidence that driving under the influence of cannabis is less deadly than driving under the influence of alcohol. Several studies have suggested that a driver who is high on marijuana is around twice as likely to be involved in a fatal accident as compared to a sober driver. That is a matter of concern. However, it is estimated that a drunk driver is almost 18 times more likely to be involved in a fatal accident!