The issue of marijuana legalization has long involved a contentious debate between two opposing groups, with each frequently marshaling research to bolster its position. In only the last few weeks, there have been several conflicting studies that have received attention, further confusing the question of whether legalized marijuana increases or decreases safety to those on the country’s roadways.

The first report that was seized on by opponents to legalization came from a recent article in the American Journal of Epidemiology. That study found that in the past 10 years, the number of deadly traffic accidents where one driver was found to have marijuana in his or her system tripled. In 1999, only 4.2 percent of fatal traffic accidents involved marijuana, while 12.2 percent of deadly crashes in 2010 saw drivers with marijuana in their systems.

The news was shocking to many and seemed to confirm the worst fears of those opposed to further legalization. Opponents of legalization said that marijuana use, much like alcohol, slows a driver’s reaction time, dulls the senses and can make decision-making difficult. Given the results of the survey, it appeared clear that continued marijuana legalization would lead to potentially deadly results years down the line.

However, others have criticized the study for not making clear that the tests identifying drivers with marijuana in their systems actually measured the presence of THC metabolites, not actual impairment. THC metabolites are the things that remain in a person’s body after someone has consumed marijuana and do not necessarily indicate impairment.

Advocates for legalization point to a 2012 study by the National Highway Traffic Safety Administration, which found that the only significant effect that marijuana had on the operation of a motor vehicle was to slow the speed of the driver. Additionally, researchers at the University of Colorado tracked results from 13 states that legalized medical marijuana usage between 1990 and 2009 and found that traffic fatalities in those states dropped by nine percent during that period.

Interestingly, the study found that following legalization, beer sales in those states fell by around five percent. The researchers said that the data suggested that legalization could decrease traffic fatalities by reducing overall alcohol consumption, specifically among young drivers.

Though no one believes driving while high is actually safe, there appears to be significant disagreement over just how dangerous the legalization of marijuana is. The hope is that additional studies are conducted so that legislators in other states, including here in North Carolina, can make informed decisions to best protect drivers from the harm of dangerous impaired drivers.

CA