Reefer Madness on the Road
Reefer Madness on the Road
Since January 2014, there have been a flurry of reports in the media about seemingly dramatic increases in traffic fatalities caused by “marijuana-positive” drivers.
The news items seem to have been generated by a study published in the American Journal of Epidemiology that culled toxicology data on drivers involved in fatal traffic accidents in six states – California, Hawaii, Illinois, New Hampshire, Rhode Island, and West Virginia – between 1999 and 2010. While alcohol was the main culprit for approximately 40 percent of the cases, drugs were attributable to 28 percent of traffic deaths in 2010. According to the study, marijuana was the main drug involved in 12 percent of those crashes, which was three times greater than the numbers found only a decade earlier in 1999.
Some news agencies took the information a step further by linking the surge in deaths to the rise of medical marijuana sales in 20 states, which seemed to indicate that the legalization movement was fueling a wave of homicidal motorists high on weed.
The facts behind the facts, however, reveal a much more accurate depiction of the relationship between traffic accidents and marijuana use. The American Journal study itself showed that the presence of cannabinol - the metabolite of THC - in the system of a driver involved in a fatal crash does not indicate that he or she was under the influence at the time of the accident. Traces of cannabinol can be found in the blood system for up to a week after use, which largely nullifies its status as a smoking gun.
As the study’s authors themselves noted, “The prevalence of nonalcoholic drugs… should be interpreted as an indicator of drug use, not necessarily as a measure of drug impairment.”
As for the connection between the rise of traffic fatalities and the expansion of medical marijuana, only three of the six states included in the study had medical marijuana laws: California, Hawaii, and Rhode Island. Furthermore, traffic deaths actually decreased in all three states between 1996 and 2010, with California experiencing a 31 percent drop, which reflected the nationwide reduction in such incidents during the same time period.
Have these statistics changed in the wake of more recent legalization efforts across the country? According to findings published by the National Bureau of Economic Research, traffic fatalities in Washington, which was the first state to officially legalize marijuana, experienced a minor spike in fatal crashes from 403 to 405 between 2012 and 2013, while Colorado, which followed suit soon after, dropped from 434 to 428 during that same period.