How can the police tell if you're driving while high?
It's not simple.
There's no breath test like there is with alcohol to determine whether a driver is under the influence of drugs.
Instead, law enforcement agencies rely on specially trained officers, known as "drug recognition experts," who know how to spot the tell-tale signs of impaired driving. The officers, who undergo a month of training followed by yearly refresher courses, use a combination of field sobriety tests – like standing on one leg – as well as observations of vital signs and sometimes searches of a vehicle to make the call.
Kevin Sturmer, a patrol trooper with State Police Troop A, which covers Western New York, has been trained as a drug recognition expert for a decade now. He estimates he is called in to lend his expertise to suspected cases of impaired driving about 100 to 120 times a year.
"I try never to assume someone's impaired," said Sturmer, as he patrolled through the streets of Clarence on a recent drizzly morning.
There are 303 drug recognition expert law enforcement officers in New York State, with at least 15 in Erie County's various police agencies, including Sturmer, and six in Niagara County. In the coming years, many more are expected to be trained.
The latest revision of the Marijuana Regulation and Taxation Act, sponsored by Assembly Majority Leader Crystal Peoples-Stokes, D-Buffalo, includes $1 million to be used over three years to train more law enforcement in identifying impaired drivers.
Regardless of whether marijuana is legalized, driving while impaired by cannabis products would remain illegal, just as driving while intoxicated by alcohol or impaired by a prescription drugs is, law enforcement authorities say.
Erie County District Attorney John Flynn has said repeatedly that his main concern regarding legalizing pot is its impact on drivers.
"My No. 1 priority now is the safety of the roads," Flynn said in January. "I'm going to prosecute these cases strongly."
The tell-tale signs
Sometimes it's pretty obvious when a driver is too impaired to drive – and not just by alcohol.
Sturmer recalled being called in to evaluate a young woman who had been pulled over. He asked her to close her eyes, tip her head back and bring her finger to her nose – part of the standard evaluation.
"She started acting like she was playing cards," he said, mimicking how the woman mimed drawing invisible cards and laying them in front of her.
He said he asked her to try one more time. She did it again.
But often it takes a series of tests.
Most often, Sturmer isn't the one making the roadside arrests. Drug recognition expert officers like him are generally brought in to the station or hospital to evaluate the driver suspected of being impaired by drugs.
He goes through a 12-step evaluation that includes a breath alcohol test, interviews with the subject and the arresting officers, pulse check and other vital signs, eye exams, tests like the finger to the nose or standing on one foot, muscle tone check, search for injection sites and finally toxicology tests of either urine or blood. Urine samples can be provided at a station, but blood can only be drawn at a hospital.
There's no way to say definitively that a person is impaired by a particular drug, Sturmer said.
"But you can tell the category," he said – depressants, stimulants, hallucinogens, dissociative anesthetics, narcotic analgesics, inhalants and cannabis.
Constricted pupils are a sign of opioids or other narcotic analgesics, or painkillers, he said.
Impaired perception of time and distance, like stopping too short or way beyond a stop sign or not being able to judge what 30 seconds is, could be an indicator of cannabis use.
They don't differentiate between legal and illegal, or prescription or nonprescription drugs.
And it is common for police to pull over people who have taken a drug they have a prescription for – and are too impaired by it to drive safely.
"People look at their prescription that says, 'Do not operate heavy machinery,' and think: I'm not driving a bulldozer or a forklift. I'm fine," said Trooper James O'Collaghan, spokesman for the State Police Troop A, which covers Western New York. "They're not. Most cars weigh 4,000 pounds. That's heavy machinery."
A look at Colorado
Colorado, which legalized recreational marijuana in 2013, offers a case study for other states. The western state is the only one among the 10 states and Washington, D.C., where recreational use of pot is legal that has set the legal limit for driving while impaired by cannabis at 5 nanograms per milliliter of "Delta-9 THC," the active component in marijuana. It can only be determined through a blood test.
Here are some findings from the Colorado Division of Criminal Justice about driving and marijuana:
- Colorado increased the number of trained drug recognition experts from 129 in 2012 to 214 in 2018. Thousands more have been trained in "advanced roadside impairment detection."
- The Colorado State Patrol said driving under the influence cases dropped 15% from 2014 to 2017.
- The percentage of state patrol citations for marijuana-only impairment stayed steady at about 7%, but the percentage for citations "with any marijuana nexus" rose from 12% in 2012 to 17% in 2016, but then came down to 15% in 2017.
- 10% of people in treatment for a DUI "self-reported marijuana as their primary drug of abuse," compared with 86% who reported alcohol.
- The percentage of drivers in fatal crashes who tested positive for Delta-9 THC at the 5ng/mL decreased from 11.6% in 2016 to 7.5% in 2017.
- The number of fatalities where a driver tested positive for any cannabinoid (THC, CBD, etc.) increased from 55 (11% of all fatalities) in 2013 to 139 (21% of all fatalities) in 2017.