A new Connecticut study has put cannabis and traffic fatalities back under the spotlight. Researchers found that more people killed on the state’s roads tested positive for the drug after recreational use became legal in 2021. However, the authors admit the data cannot show whether cannabis played a part in any single crash.

What the Connecticut Data Shows

The analysis appeared in the American Journal of Forensic Medicine and Pathology. It reviewed seven years of records from the Office of the Chief Medical Examiner, covering 2018 to 2024. That gave the team three and a half years of data on each side of legalisation. In total, the records included 1,168 drivers and 380 pedestrians who died in crashes.

For cannabis and traffic fatalities, the numbers moved in one direction. Among drivers, the share who tested positive for cannabis rose from 32.8% to 37.9%. The researchers also reported a statistically significant rise in motorcyclist deaths involving cannabinoids after legalisation. They wrote that cannabis “may play a growing role” in fatal crashes.

Pedestrian Deaths Show the Sharpest Jump

The biggest shift in cannabis and traffic fatalities came among people on foot. Cannabinoid positivity in pedestrians climbed from 11% before legalisation to 20.6% afterwards. That is close to double.

Dr. Eric Jackson, a research professor at the University of Connecticut and executive director of the Connecticut Transportation Institute, found this group the most noteworthy. He said it leaves open the possibility that more people are being hit by vehicles after using cannabis and choosing to walk rather than drive. It remains unclear whether those pedestrians felt any effects.

Dr. Stacy Thomas, the study’s lead author and a hospital resident at the Yale School of Medicine, pointed to a gap in public messaging. “There is a lot of advocacy to not drive impaired,” she said. “But there’s not the same sort of advocacy to not leave your house and walk the streets impaired.”

Alcohol Often Appears Alongside Cannabis

Cannabis was rarely the only substance found in these fatal crashes. The researchers noted that “multidrug detection was common” among those who tested positive, and alcohol was the most frequent partner.

Dr. Khuram Ghumman, associate dean for strategic partnerships at the Frank H. Netter MD School of Medicine at Quinnipiac University, said the two substances often go together. Even so, he called it “hard to say” whether that means someone used cannabis shortly before a fatal crash.

He did stress the risks. Cannabis can slow reaction time and reduce coordination. Speed, distracted driving and missing seatbelts are common in serious crashes. Together, these factors can make an already risky situation much riskier.

Why Cannabis and Traffic Fatalities Data Comes With Caveats

Thomas said there are “a lot of caveats with the data.” For one, the study period fell during the pandemic, when driving patterns changed. Road deaths in the state spiked and then peaked in 2022. Therefore, the team cannot say whether any rise in cannabis and traffic fatalities reflects intoxication or simply a shift in how people travelled.

Testing also poses a problem. Unlike alcohol, the mere presence of THC does not prove impairment. “Just by looking at a number, we unfortunately don’t have any data to say whether or not there is impairment or if there’s just use,” Thomas said.

Jackson explained why. “Cannabis is fat soluble,” he noted. “It can be stored in your cells.” A person can consume it, wait three weeks, then burn fat through a hard workout and find it back in their system. Jackson said he expected an even larger jump in positive tests because the drug lingers for so long.

Geography muddies the picture too. Massachusetts legalised recreational cannabis a decade ago, and it sits a short drive away. Some Connecticut residents were therefore already using it before the 2021 change.

What Comes Next for Road Safety

Police face a further hurdle when tackling cannabis and fatal crashes. There is no cannabis equivalent of a blood alcohol limit. “We don’t even know if there is such a thing for cannabis,” Jackson said. He believes the findings show a need for more officers trained as drug recognition experts, since Connecticut still relies on those who have completed that extra training.

The experts agree that nothing in the data should send state officials into a panic over legalisation. Yet they also say the trend deserves a closer look. The authors described their findings as useful for “understanding and responding to evolving drug trends in traffic fatalities.”

For now, the study leaves an open question. Cannabis and traffic fatalities are clearly linked in the records, but the cause behind that link is still unproven.

Source: courant