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Under the Influence: Drunk Driving Arrests Down & Drugged Driving Up!

A recent study published in the Journal of Alcohol and Drug Dependence analyzed American traffic data and found that since 2007, drunk driving arrests had fallen almost 33% but the study found a disturbing new increase; they also illustrated that the NHTSA found “drugged driving” accidents and arrests up by 50%.

With marijuana becoming legal for medical use in 23 states, legal recreationally in 5 states and DC, (and Ohio deciding by vote this November), our roads now have drivers legally intoxicated with THC, as well as drivers under the influence of alcohol.  There is obvious value in comparing the effects of marijuana intoxication with, and alongside, drunk driving. The researchers observed a small number of alcohol-induced drivers and THC-induced drivers performing equally badly re: weaving, but the research found that “only alcohol increased lateral acceleration and the less-sensitive lane departures/min parameters”  (lane departure and lane recovery times).  Further study showed that volunteers simulating driving under the influence of both alcohol and marijuana showed an “additive but not synergistic” effect of concurrent use.


Within the last few years, there has been tremendous political tension and attention paid toward state legislators having moral prohibitions against marijuana that do not transfer to alcohol, as well as “unfair” and harsh punishments for marijuana possessions, but there has not be an equally ambitious and comprehensive response to driving laws across the country.  “Since legalizing medical marijuana, Colorado has reported an increase in driving under the influence of cannabis cases and fatal motor vehicle crashes with cannabis-only positive drivers while states without legalized marijuana have experienced no significant change in cannabis-related crashes.”


Reference: Marilyn A. Huestis et al. Cannabis Effects on Driving Lateral Control With and Without Alcohol. Drug and Alcohol Dependence, June 2015 DOI: 10.1016/j.drugalcdep.2015.06.015

Patrick Logan,
MS is a former wilderness therapy program manager and now consults with programs and websites about general I.T. issues, database and website support, proofreading and branding projects.