Marijuana, Opioids Rival Alcohol As Factors in Traffic Fatalities

Greg Gardner

Marijuana, opioids and non-alcoholic drugs are more likely to be found in drivers killed in vehicular crashes than alcohol, according to a new study released Thursday by the Governors Highway Safety Association.

The study, titled “Drug-Impaired Driving: Marijuana and Opioids Raise Critical Issues for States,” does not dismiss the danger of drunk driving. But it does find that broader legalization of recreational marijuana use and the ongoing epidemic of opioid addiction have forced a more expansive view of impaired driving. That, in turn, raises the question of what, if any sanctions are appropriate for those who drive while drugged.

Here are the numbers: in 2016, 44% of fatally-injured drivers with known results tested positive for drugs, up from 28% in 2006. More than half of these drivers had marijuana, opioids or a combination of the two in their system.


Over that same period the presence of alcohol in fatally-injured drivers fell slightly from 41% in 2006 to 38% in 2016.

Jim Hedlund, a former official with the National Highway Traffic Safety Administration and author of the study, said that some strategies deployed to discourage drunk driving can be effective to reduce the risk of drug-impaired driving, but non-alcoholic drugs present testing challenges.

For example, there is no national method for testing driver drug impairment. How do you distinguish the presence of marijuana from methamphetamines, cocaine or opioids? Different drugs have different impairing effects in different drivers.

Predictably, alcohol is often mixed with other drugs as a factor in fatal and non-fatal crashes.

In 2016, 51% of drug-positive fatally-injured drivers were found positive for two or more drugs.

Alcohol is often in the mix as well: 49% of drivers killed in crashes who tested positive for alcohol in 2016 also tested positive for drugs.

Because law enforcement officials have more accurate ways to measure alcohol levels than levels of other drugs, the impact of marijuana and opioids may be understated.

“Among those arrested for DUI, if law enforcement finds their blood-alcohol concentration is above the legal limit, they really have no reason to test for any other drugs,” said Erin Holmes, director of traffic safety with Responsibility.org, a non-profit funded by a group of distillers aiming to prevent drunk driving.

Without more robust testing processes "the presence of the drug itself can't prove impairment to the degree that the drug was the cause of the accident," Holmes said.

GHSA’s research is just the latest in a series of reports examining whether traffic risks are increasing with marijuana legalization.

Earlier this month the Insurance Institute for Highway Safety examined insurance claims for traffic accidents filed between January 2012 and October 2016. IIHS compared claims in Colorado, Washington state and Oregon – all of which have legalized marijuana – with claims in neighboring states that had not legalized.

Collision claim frequency was measured by dividing the number of claims by the number of insured vehicle years.

The upshot: Claims were 3% more frequent in Colorado, Washington and Oregon than in the neighboring, non-legalized states, a diffierence the institute described as “small, but significant.”

Shortly after the IIHS released its report, the American Journal of Public Health published an analysis that found no increase in vehicle crash deaths in Colorado and Washington, compared with similar states where marijuana use is not legal. That study looked at driver fatality data between 2009 and 2015.


GSHA and Responsibility.org have been training law enforcement officers to better recognize the signs and symptoms of impairment by different types of drugs.

They also recommend the following education and policy initiatives:

• Closely follow development and testing of new impairment assessment tools, such as oral fluid devices and marijuana breath test instruments
• Support drug-impaired driving prosecution through increased law enforcement training, authorize electronic search warrants for drug tests, and educate prosecutors and judges about the unique challenges of drugged driving cases
• Partner with leaders from public health, pharmaceutical and marijuana industries to educate patients and customers about the potential impairing effects of various drugs
• Use public awareness campaigns to change driver attitudes about driving under the influence of marijuana and opioids.