DETROIT (AP) — A large study by U.S. traffic safety regulators has found that more than half of people injured or killed in traffic crashes had one or more drugs or alcohol in their bloodstream.
Additionally, just over 54% of injured drivers had drugs or alcohol in their system, with tetrahydrocannabinol (THC), an active ingredient in marijuana, being the most prevalent, followed by alcohol, according to the study released Tuesday by the National Highway Traffic Safety Administration.
Although the study authors say the results cannot be used to assess drug use on the roads nationwide, they say the high number of drivers, passengers and other road users road with drugs in their system is concerning.
NHTSA Acting Administrator Ann Carlson said the study found nearly 20% of drivers tested had blood alcohol levels of 0.08% or higher, exceeding the legal limit in every state.
“We are also concerned that almost 20% of road users have tested positive for two or more drugs, including alcohol,” she said. “Using multiple substances at once can amplify the harmful effects of each drug.”
The study of blood tests performed at seven level one trauma centers and four medical examiners’ offices 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 and more states are legalizing the recreational use of marijuana with research just beginning on the 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 frankly, I don’t think I’m that surprised.”
Brooks, who is based in Washington, DC, said he often sees people driving after drinking or smoking cannabis.
“Not a drive goes by that I don’t smell marijuana on the road, from someone actively smoking in a car in front 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. Forensic pathologists from four of the sites 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 bloodstream.
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, according to the study.
The study was set up to measure the prevalence of drug and alcohol use, but the figures cannot be used to show drug use on the roads nationwide because hospitals do not have not been chosen to represent the entire country, said Amy Berning, a research psychologist at NHTSA. and one of the study’s authors.
The study also cannot be used to show a correlation between the increasing number of road deaths and drug use, although it stated that detecting such a high percentage of use with a sample of large size is “a concern for NHTSA”.
The researchers counted any drug levels in the blood samples and did not measure whether people were intoxicated, Berning said. It will likely use the data as a basis for further study of the issue, she said. NHTSA is planning a national roadside survey to measure alcohol and drug use on the roads. He 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 blood longer than alcohol or other drugs, Berning noted.
The study was released as NHTSA launched its annual holiday campaign against impaired driving.
“Developing a plan for a safe and sober ride home is key to saving lives this holiday season,” Carlson said.