Billboards and restaurant bathroom ads are already in circulation: “Drive the highway, not the high way.”
Broadcast public service announcements are direct, too: “Driving high is a DWI.”
Beginning next Tuesday, Aug. 1, marijuana possession and use will be legal for adults 21 and older. And with that shift in state drug policy comes a stepped-up awareness campaign to advise people that not everything goes and that law enforcement will be on alert for drug-impaired drivers.
There are some important rules of the road to consider: Ingesting cannabis products while driving remains illegal. So does having marijuana easily accessible in a moving vehicle.
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And as Minnesota State Patrol chief Colonel Matt Langer says, “It's illegal to drive impaired, regardless of what substance you're on.”
State officials predict marijuana use will go up as its legal status changes and as more forms of cannabis become readily available. Widespread retail sales are still many months away, but homegrown marijuana will be allowed immediately.
Long before legalization, Minnesota officers encountered drivers they believed were impaired by marijuana.
Cottage Grove police officer Matt Sorgaard has been involved in dozens of stops for suspected drug impairment, sometimes called in as backup given his prior training as a drug recognition evaluator or DRE.
He said common patterns are drivers struggling to maintain a steady speed, straying in a lane, getting too close to a car ahead or rolling beyond a stop sign — all signs of slowed reaction time.
Once a driver is pulled over, Sorgaard said there are other telltale clues from what officers smell to what they observe.
“They have conjunctivitis, which is usually reddening of the eyes,” he said. “Sometimes you can see eyelid tremors or body tremors when it comes to marijuana use. So that's eyelids flickering or their bodies just involuntarily tremoring. They don't notice that they're doing it.”
Field tests evaluating a person’s gaze, balance and cognitive function can reveal more.
“You have these people on the side of the road, you tell them to close their eyes and estimate the passage of 30 seconds,” Sorgaard said. “And we'll stand there for two, three minutes while they're trying to do this because their internal clock is just really slowed down. They’re relaxed.”
Sorgaard recently changed assignments, but Minnesota plans to dramatically build up the ranks of officers with DRE skills.
“Our officers can do that initial observed driving conduct, do the initial field sobriety tests out there and can just show that this person is impaired and we don't necessarily know what they're on or what's causing the impairment,” said Eden Prairie Police Chief Matt Sackett.
Sackett recently added a second DRE to his 74-officer force.
DREs do more-intensive exams – commonly away from the scene of a stop – around vital signs, pupil dilation and body cues to make determinations if it’s marijuana, another controlled substance or occasionally a medical condition that's likely at play. A fluid test is sometimes sought but lab results can take weeks or longer to obtain.
There are about 300 DREs now across the state, with one-third of them working for the State Patrol and the rest for local police or sheriff’s departments.
Office of Traffic Safety Director Mike Hanson said the plan is to certify up to 100 more in the next year toward a goal of having 500 before long.
“We need to put this incredibly powerful tool in their hands,” Hanson said. “Many of our prosecutors tell us that the key to proving that drug-impaired driving arrest often comes down to that DRE's ability to recognize the signs, the symptoms, the physiology of somebody who is under the influence of something other than alcohol.”
Becoming a DRE involves 10 days of classroom time, participation in field exercises and steps to maintain certification later. Dozens of Minnesota officers were headed to Philadelphia this month for field evaluations and more are awaiting that trip.
Hanson said training just one officer can cost $26,000, which is why the Legislature set aside millions of dollars to defray the expense as part of the marijuana bill that passed in May.
Public safety leaders say marijuana use is only part of their concern. These days, officers routinely come across drivers on multiple substances – combinations of alcohol or drugs – that compound impairment.
The most recently available state data covering January 2021 through June 2022 found cannabinoid drugs were found in more than half of the 7,000 blood and urine samples collected during stops where drug impairment was suspected.
But for marijuana, there’s no standard breath test to tell if somebody is above a set limit – like the 0.08 percent threshold for alcohol.
“There’s never going to be a BAC for THC. It just doesn’t exist and it won’t exist,” said Mark Stodola, who is steeped in nationwide DUI policy as a fellow for the American Probation and Parole Association.
Stodola, who led a presentation at a Minnesota court conference this summer, said how a person takes cannabis in and the way the body processes make it difficult to set a threshold for impairment. Smoking a joint or drawing off a vape device results in a quicker high than consuming a THC-infused edible or beverage that might not kick in for hours.
And, he said, potency matters.
“The Woodstock marijuana really doesn't exist anymore,” Stodola said. “That was like five nanograms of active THC. The stuff you buy today is much, much stronger than that.”
The variety of ways to ingest marijuana poses challenges to officers trying to prove impairment or use while a car is in motion.
“Twenty years ago, if a law enforcement officer saw somebody in a vehicle with a joint in their hand, or they walked up to the vehicle and marijuana smoke is billowing out the driver's side window, you pretty much knew what you had going on,” Stodola said. “But if you drive next to somebody, and they're vaping, what does that mean? Could be marijuana could be flavored tobacco. It could be any number of things.”
Defense attorneys anticipate a jump in cases, too. They point to the potential for more marijuana users and the push to boost the number of DREs.
“There's going to be a lot more hammers out there. So there's gonna be a lot more hammering down on what looks like a nail to that person,” said Thomas Gallagher, a criminal defense attorney in Minneapolis who also teaches courses for lawyers on marijuana-related arrests.
He advises prospective clients against consenting to field sobriety tests because the results are open to interpretation. Instead, he said chemical testing is a better route, with breath, blood and urine tests the ones used now in DUI enforcement in Minnesota.
“Only one of those can detect THC right now. And that is blood,” Gallagher said. “You could have it in your urine, but you don't have any in your blood or almost none because it burns off super fast. If they don't have a blood test, they don't got a case is what it kind of boils down to.”
In September, Minnesota will begin a yearlong experiment with an oral fluid test to detect marijuana. But that won’t be admissible as evidence for now. So DWI enforcement for marijuana will lean heavily on squad or bodycam video and officer observations.
“That roadside interaction and the driving conduct is really critical for all drug-impaired driving,” said the State Patrol’s Langer. “Cannabis is unique in that we have to prove impairment, not just the presence.”