A new study by the Insurance Institute for Highway Safety found that auto accidents rose in states that legalized recreational marijuana. Car crashes with injuries jumped 6% while fatal auto accidents increased 4%. Comparison states that did not legalize recreational marijuana saw no increase in these types of accidents. The states that legalized recreational marijuana examined in the study were California, Colorado, Nevada, Oregon, and Washington. The comparison states where cannabis is not legal were Arizona, Idaho, Montana, New Mexico, Utah and Wyoming.
The rate of accidents varied by state. After legalization when retail sales began, car crashes jumped 18% in Colorado, while accidents decreased 7% in Nevada. Oddly enough, after retail sales began fatal crashes increased in Colorado and Oregon (1% and 4% respectively), while decreasing in California (8%) and Nevada (10%). Researchers noted that car crashes jumped after states legalized recreational marijuana even before retail sales began.
They found that after legalization, but before retail pot sales started, the rate of car crashes with injuries jumped nearly 7%. After sales began, the crash rate dipped slightly (less than 1%), but the rate of fatal crashes shot up about 2% before and after retail sales began.
The authors note that people under the influence of marijuana change their driving behavior:
Often, drivers under the influence of marijuana drive slowly, the researchers noted. They may not be able to avoid a crash, but their lower speed may make the collision less deadly, Farmer noted.
In previous studies, Farmer’s team found that marijuana use affects reaction time, road tracking, lane keeping and attention, all of which can make a crash more likely.
Whereas there is public awareness of the effects of alcohol on driving, there is less public education about marijuana use while driving. There are no objective measures of impairment linked to marijuana, although public education should help. The authors note there also needs to be an enforcement mechanism like what is used by police to detect blood alcohol levels.
Read more at US News: Where Pot Became Legal, Car Crash Deaths Rose