Drugged Driving Surpasses Drunken Driving in Deadly Crashes, Study Says

A new study finds that of American drivers killed in car crashes, incidents with drugs have surpassed those with just alcohol, NBC News reports. The Governors Highway Safety Association and the alcohol distiller-backed nonprofit Foundation for Advancing Alcohol Responsibility released the report.

Both illegal and prescription drugs were involved in 43 percent of deadly 2015 car crashes while about 37 percent involved alcohol. More than one-third of those who took drugs used marijuana, The Washington Post notes.

Testing for a majority of drugs is tricky, as there isn't something akin to a Breathalyzer test for them, NBC News reports. The governors association wants law enforcement to have more training for such cases. Such training is already going on in California with the California Highway Patrol.

"As states across the country continue to struggle with drug-impaired driving, it’s critical that we help them understand the current landscape and provide examples of best practices so they can craft the most effective countermeasures," Jonathan Adkins, the executive director of the Governors Highway Safety Association, said in a statement.

The study did have limitations, in that the foundation relied on state report data which weren't always comparable. States were different in what drugs they tested for – not to mention the frequency of tests. Moreover, the data indicate drug presence but not the drug amount as you'd learn in a blood-alcohol test.

The impact of marijuana laws, which have made recreational marijuana legal in eight states and the District of Columbia as of this year, isn't immediately clear, NBC News reports. The report cited multiple studies regarding weed and deadly crashes. One study from 2013 said crashes involving marijuana rose in just three states out of 14 that had medical marijuana laws prior to 2010.

The report cautions that a combination of multiple vices bodes particularly poorly.

"Impairment can increase if drugs are used in combination or together with alcohol," according to the study. "Alcohol and marijuana used together are particularly risky."

"Drugged driving is a complicated issue," according to Jim Hedlund, a former National Highway Traffic Safety Administration official and author of the report. "The more we can synthesize the latest research and share what's going on around the country to address drug-impaired driving, the better positioned states will be to prevent it."