Monroe County Sheriff Luis Blasco conducts a field sobriety test at a DUI traffic checkpoint in July 2007 in Miami. Photo by Joe Raedle, courtesy Getty Images

Monroe County Sheriff Luis Blasco conducts a field sobriety test at a DUI traffic checkpoint in July 2007 in Miami. Photo by Joe Raedle, courtesy Getty Images

As drunken driving crashes continue to decrease nationwide, a new roadway risk is growing — and unlike alcohol-impaired driving, there is no national guideline to corral it.

Whether caused by drugs that are illicit, prescribed or otherwise legal, drugged driving is gaining attention. About 10 million people report driving under the influence of illicit drugs, according to “Behavioral Health Trends in the United States: Results from the 2014 National Survey on Drug Use and Health.” The report, from the U.S. Substance Abuse and Mental Health Services Administration, details Americans’ drug use, including behind the wheel.

About 4,000 people are killed every year in traffic crashes in which a driver was on the road with drugs in her or his system. But public health experts say that number may be much understated, downplaying the possible risk to drivers and pedestrians alike.

Visit The Nation’s Health online to continue reading this story from the Oct. 2016 issue.