Still, there’s no doubt that drugged driving is a growing problem, and one that, coincidentally or not, dovetails with expanding decriminalization of marijuana around the country. Although state-by-state data that would allow us to better isolate the impact of legalization isn’t available, marijuana is the principal drug responsible for the growing proportion of drugged drivers. 

Random sample data shows a 48% increase in positive tests for THC metabolites over the last decade,3 and more than one-third of drivers in drugged-driver fatal crashes have marijuana on board.

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However, no one is quite sure of the actual extent to which drugged driving is problematic. Recent studies have shown that drivers under the influence of marijuana and alcohol are more likely to make errors than drivers under the influence of only one of those substances, and that drivers who have smoked up are more prone to mistakes than those who haven’t.4

But who’s to say that the growing prevalence of THC-positive drivers isn’t mostly a consequence of remote smoking by chronic users who aren’t intoxicated when piloting their vehicle? The reality is that the two positions aren’t mutually exclusive.

And none of this even begins to address whether there’s a connection between the burgeoning opioid epidemic and the spike in drugged driving. The Department of Transportation is, on record, downplaying the idea. The statistical link is tenuous at best. Both marijuana and amphetamines are substantially more likely than opioids to be found in the blood of drugged drivers.

But the coincidence feels too obvious to completely ignore. The position of Mothers Against Drunk Driving (MADD) and other advocacy groups is that we’re best served by stricter surveillance and enforcement combined with more support for programs that are designed to help vulnerable people avoid drug abuse in the first place.5

That brings us back to Tiger. All things considered, it was pure serendipity that the police spotted him and pulled him off the road before anyone got hurt. And after the initial uproar surrounding his arrest had died down, he announced that he would be seeking “professional help” to aid in the management of prescription drug use for back pain. Together, those sound an awful lot like the solutions put forth by MADD and others. Maybe Tiger’s rock bottom is pointing to a way forward in the fight against drugged driving.


  1. Associated Press. “Tiger Woods DUI Arrest: Golfer Said He Took Xanax.” Time. Updated June 10, 2017. Available at: Accessed June 23, 2017.
  2. Simpson I. “Drug Use Tops Booze for First Time in Fatal US Crashes: Study.” Reuters. Updated April 26, 2017. Available at: Accessed June 23, 2017.
  3. Berning A, Compton R and Wochinger K. “Results of the 2013-2014 National Roadside Survey of Alcohol and Drug Use by Drivers.” Journal of Drug Addiction, Education and Eradication. 2015;11(1): 47.
  4. Diedrich S. “UI Studies Impact of Marijuana on Driving.” Iowa Now. Updated June 25, 2015. Available at: Accessed June 23, 2017.
  5. Bomey N. “Spate of Drugged Driving Deaths Alarms US Regulators.” USA Today. Updated October 27, 2016. Available at: Accessed June 23, 2017.