DETROIT (AP) — A major study by U.S. road safety regulators found that more than half of people injured or killed in traffic accidents had one or more drugs or alcohol in their bloodstream.
Also, just over 54% of injured drivers had drugs or alcohol in their system, with tetrahydrocannabinol (THC), an active ingredient in marijuana, the most common, followed by alcohol, according to a study published Tuesday by the National Highway Traffic Safety Administration.
While the study’s authors say the results cannot be used to measure drug use on the roads across the country, they say the sheer number of drivers, passengers and other road users with drugs in their systems is concerning.
Acting NHTSA Administrator Ann Carlson said the study found nearly 20% of drivers tested had a blood alcohol level of 0.08% or higher, which exceeded the legal limit in every state.
“We are also concerned that nearly 20% of road users tested positive for two or more drugs, including alcohol,” she said. “Using multiple substances at once can increase the adverse effects of any drug.”
The study of blood tests taken at seven Level One and Four Medical Examination Centers across the country comes at a critical time on American roads. Road deaths have risen dramatically since the start of the pandemic to what officials describe as crisis levels. And more states are legalizing recreational use of marijuana with research just beginning on its impact on road safety.
“It’s scary for all of us in a way,” said Michael Brooks, executive director of the nonprofit Center for Auto Safety, a watchdog group. “But honestly, I don’t think I’m that surprised.”
Brooks, who lives in Washington, D.C., said he often sees people driving after drinking or smoking cannabis.
“Not a commute goes by without me smelling marijuana on the road, from someone actively smoking in a car ahead of me,” he said.
The study took place between September 2019 and July 2021 at trauma centers in Miami and Jacksonville, Florida; Charlotte, North Carolina; Baltimore; Worcester, Massachusetts; Iowa City, Iowa; and Sacramento, California. Medical examiners at four of the locations also participated.
The study, which took blood test data from 7,279 road users, also found that more than half of injured pedestrians and just over 43% of injured cyclists had a drug in their blood.
Of the total number of patients, 25.1% tested positive for THC, 23.1% for alcohol, 10.8% for stimulants and 9.3% for opioids, the study said.
The study was designed to measure the prevalence of drug and alcohol use, but the numbers cannot be used to show drug use on the roads across the country because the hospitals were not chosen to represent the entire country, said Amy Berning , an NHTSA research psychologist. and one of the study’s authors.
The study also can’t be used to show a link between increasing traffic fatalities and drug use, though she said detecting such a high rate of use with a large sample size “is a concern for NHTSA.”
Researchers counted each level of drugs in blood samples and did not measure whether people were disabled, Berning said. It will likely use the data as a basis for further investigation of the problem, she said. NHTSA is planning a nationwide roadside survey to measure alcohol and drug use on the road. It last conducted such a survey in 2013 and 2014.
The presence of THC in so many patients could be because it can stay in the bloodstream longer than alcohol or other drugs, Berning noted.
The study was released as NHTSA began its annual holiday season campaign against drunk driving.
“Making a plan for a safe, sober ride home is critical to saving lives during the holiday season,” said Carlson.