Marijuana and driving: Enforcement tools, data collection lag legalization, experts say

On a recent Friday afternoon outside a cannabis shop in Farmingdale, the smell of marijuana drifted through the parking lot as a driver casually smoked a joint in his Mercury Grand Marquis.

He quickly snuffed it out and peeled away when a reporter approached. Another man walked toward his car rolling a joint but said he was not going to light up while driving. He explained he normally parks elsewhere to do so.

As cannabis becomes more mainstream since it was legalized in 2021, its signature scent is also more apparent on the road. Experts, however, say traffic enforcement measures and ways to gauge the number of crashes related to driving while impaired by marijuana haven't kept up.

Arrests and crashes are not specifically tracked by substance, including marijuana. But deadly impaired crashes, which include all drugs and alcohol, have risen on Long Island, from 108 in 2019 to 146 in 2022, the most recent year that complete crash statistics are available, according to the Albany-based Institute for Traffic Safety Management & Research. Across the state, fatal impaired crashes surged to 544 in 2022 compared with 378 in 2019.

Arrests and tickets for DWI and impaired driving on Long Island, meanwhile, have dropped compared with before the COVID-19 pandemic, according to state data.

Experts said it's important to begin isolating crashes by substance to understand how to combat the issue.

“In order to proceed reasonably and reflect what everyone has seen and smelled for themselves, there has to be a dedication for better data collection both nationally and in New York,” said Maureen McCormick, a Suffolk County special assistant district attorney.

Drivers and passengers are banned from using cannabis behind the wheel, and if caught, face penalties, including arrest. But misconceptions persist.

“There are definitely people out there that think, 'Hey, this is going to make me a safer driver,' and we've got plenty of evidence that that's not the case,' ” said Alec Slatky, an AAA Northeast spokesman.

Paige Carbone, MADD regional director, said the organization focuses on combating drugged-driving crashes as well as alcohol-related ones. Carbone, who lives in Suffolk, believes cannabis legalization is contributing to an increasingly complex problem.

“We see so much more of it even in our own communities,” Carbone said. “We have seen and smelled the problems for ourselves.”

The National Transportation Safety Board has acknowledged that the failure to capture comprehensive crash data by drug type potentially thwarts appropriate countermeasures and directed drug treatment. 

Impaired deadly crashes, which spiked on Long Island in 2020 during the height of the pandemic when reckless driving climbed, have been a leading cause of traffic fatalities nationwide.

Enforcement challenges

Cracking down on driving under the influence of cannabis is not as simple as drunken driving, which is supported by decades of alcohol research. Without an impairment limit for cannabis in New York, and no widely used roadside testing tools to detect it, enforcement primarily relies on an officer's observation. 

Cannabis enforcement “relies a lot more on subjective suspicions, like subjective observations, than hard empirical data, and that's always going to make things tricky for having any type of consistent enforcement,” said Daniel Johnston, a former Nassau County assistant district attorney turned Syosset-based personal injury and cannabis industry lawyer.

Patrick Phelan, executive director at the Rochester-based New York State Association of Chiefs of Police, said some police departments are using technology still in its “infancy" to test for cannabis. Phelan said enforcement and testing is complicated by the lack of an agreed-upon scientific impairment standard for THC, the psychoactive compound that gets people high, because it can be detected in the body even when a person is not impaired. 

“How do you convict someone of being intoxicated by cannabis without an agreed-upon level of intoxication that is scientifically proven?" Phelan asked. Because of that, he believes enforcement and arrests for driving under cannabis are low. 

“I don't think it is being enforced at the level it should be and that, in-and-of itself, is making our roadways more dangerous," said Phelan, a retired chief.

A report released by Institute For Traffic Safety Management & Research in February found that despite an increase in the number of drug recognition experts trained to identify drug impairment, such evaluations dropped in 2022. According to the Department of Motor Vehicles, there are 400 trained officers throughout the state.

“We know that cannabis can be impairing. That is true and demonstrated in lab studies. And so, just like alcohol can be impairing, you want to plan your driving around this,” said Angela Eichelberger, senior researcher scientist at the Insurance Institute for Highway Safety based in Arlington, Virginia. 

Several studies have found that cannabis was the second-most common substance found in impaired driving crashes, behind alcohol. Research also has found that cannabis is normally detected in combination with alcohol or other drugs.

Long Island DAs want tougher laws

Nassau District Attorney Anne Donnelly, Suffolk District Attorney Ray Tierney and other experts said roadside tools to detect marijuana in drivers have not kept up with legalization. They also said loopholes in the law have hampered enforcement measures.

Donnelly, in an interview, pointed to a nine-day span in August where seven people were killed and six injured in four separate drug- or alcohol-related crashes in Nassau.

“What we're seeing now is more and more danger on our roads from impaired drivers,” she said. 

“I fear the legalization of marijuana paired with our archaic impaired driving laws are a recipe for disaster,” Donnelly added in an email.

Under the 2021 legalization law, police are prohibited from searching areas of a car outside a driver's reach due to the smell of weed alone, but officials said police can still pull over vehicles based on the odor. In order to conduct a full search, police need at least one other cause, such as observable impairment.

“It makes it very difficult for police officers to arrest people absent an admission. Not only difficult but virtually impossible,” Tierney said in an interview.

While driving under the influence of cannabis can lead to jail, fines and a revoked license, collecting evidence to prove cannabis impairment is more challenging in New York.

“Alcohol testing is easier and more straightforward,” said Stuart Cameron, chief of the Old Westbury Police Department and Suffolk County Police Department's former chief of department. A blood alcohol content of 0.08% is the legal limit across the country, except Utah, which has a lower 0.05% limit.

Using the roadside tests, he said, he could observe changes “at different stages of intoxication.” As an example, Cameron said that one test measures the jerking of the eyes, which is an accurate way to determine whether someone is inebriated.

The field test is also used to detect cannabis and drugs, but some studies have found it to be less reliable for those substances. Federal authorities have acknowledged that more studies are needed before rolling out a test for marijuana similar to ones developed for alcohol in the early 1980s.

No clear THC guidelines in NY 

While people understand that the body can metabolize one alcoholic drink per hour, there are no clear guidelines in New York for how much THC is safe to consume before driving.

And while cannabis affects everyone differently, it impairs driving ability by making it difficult to stay in a lane, slowing response times, lowering attention and affecting decision-making.

THC, the psychoactive compound in cannabis that gets people high, can linger in the body for days, weeks and even up to a month. How long it stays in a person’s system depends on several factors, including the concentration of THC, how it was taken, whether it was smoked, eaten or vaped, and whether someone is a chronic or occasional user. Someone with low concentrations of THC in the blood can show a greater degree of impairment than someone with a higher concentration.

New York has no impairment standard for THC. Five of 24 states that have legalized marijuana for recreational use have THC limits ranging between 2 and 5 nanograms per milliliter of blood, according to the National Conference of State Legislatures. Twelve states have zero-tolerance laws for some drugs, including THC. Alabama and Indiana have roadside screening programs to test oral fluids, like saliva, for THC. 

While neither Nassau nor Suffolk county police departments, nor New York State Police, agreed to interviews about cannabis-related traffic enforcement, the data shows impaired tickets fell in 2022, when traffic neared 2019 levels. Arrests for both felony and misdemeanor DWI arrests were also lower last year.

According to the Division of Criminal Justice Services, Long Island felony DWI arrests, which include all drug and alcohol charges from various departments, decreased 28% in 2023, the most recent year available, compared with 2019, from 688 to 470. Misdemeanor DWI arrests were down about 15.5% on Long Island last year from 2019, from 4,238 to 3,581.

Tickets issued for impaired driving on Long Island dropped in 2020 and have increased every year since, but have yet to return to 2019 levels. There were 7,523 tickets in both counties for impaired driving in 2023 compared with 8,411 in 2019, more than 10% less, according to data from the Institute for Traffic Safety Management & Research.

Nassau Police Commissioner Patrick Ryder said in a statement that the department trains all its officers “to identify individuals who are operating a vehicle while impaired by alcohol, drugs or any other substance that may alter their ability during operation.

“In order to keep our roads safe, the NCPD has a zero-tolerance approach toward driving while ability impaired,” he added.

Cannabis warning labels recommended

Some cannabis experts said it’s important to balance public safety within the parameters of the law and to understand the limits of chemical testing.

Matthew Elmes, an adjunct professor at Stony Brook University department of biochemistry and cell biology, understands that regulators would like to see an alcohol-equivalent roadside testing tool for weed, but he is worried about “falsely accusing people who are not even high,” since both Breathalyzer and saliva tests could be inaccurate by potentially picking up traces of older use.

Elmes, a cannabis scientist, said studies have found that the effects of THC on driving are similar to behaviors exhibited by drowsy or elderly drivers whose reaction time might be delayed. He echoed a recommendation made by the National Transportation Safety Board, that cannabis products include a warning label.

“It should be treated more like a prescription drug with a warning on the bottle like: ‘Do not drive or operate heavy machinery while using this,' ” he said.

Questions about cannabis legalization and traffic enforcement are surfacing across the country, according to Howard Hall, a member of the Virginia-based International Association of Chiefs of Police.

Colorado, which was the first state to vote to legalize marijuana in 2012, saw 101 deadly crashes linked to cannabis, and possibly other substances, in 2022. That’s a surge since 42 such deaths in 2018, according to data posted on the state’s Department of Transportation website. 

It's statistics like these that have traffic experts focused on preventing people from getting behind the wheel impaired by cannabis and planning alternative modes of travel instead.

“We want to make sure that legalization in people's mind doesn't mean, hey, this is a free for all and you're good to drive,” the AAA's Slatky said.