Driving high is illegal in Michigan. Soon, cops may be able to test for it

• A Michigan bill proposes allowing police to use roadside saliva tests to detect drug use in suspected impaired drivers
• The test screens for substances like THC, cocaine and fentanyl 
• Nationwide, 24 states use the tests but they are dogged by reliability concerns

More than six years after Michigan voters legalized recreational marijuana, momentum is building to allow police to use oral testing of motorists to determine if they’re driving under the influence.

Voters in 2018 legalized all forms of weed, but a lack of reliable testing has forced police to rely on anecdotal evidence  — such as bloodshot eyes and the smell of pot — to make arrests.

Now, a bill in Lansing would allow Michigan to follow the lead of 24 states and use roadside tests of saliva to give police probable cause to arrest motorists and take them in for more testing to confirm their intoxication.

“It’s just a tool to let them know if (the officer) had some reasonable suspicion … that they're under the influence of a narcotic,” said state Rep. Brian BeGole, R-Perry, who is sponsoring the legislation.

The National Transportation Safety Board recommends that states adopt the tests, which come as concern increases about drug-involved crashes.

While drug-impaired crashes have decreased since the pandemic, 230 people died from them in Michigan in 2023, according to the recent data for the Michigan State Police.

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Driving while high has similar punishments to drunk driving — 93 days in jail — but there is no defined legal blood content legal for marijuana, unlike alcohol. And testing for marijuana is tricky because the intoxicating ingredient — THC — stays in the bloodstream long after usage. 

Defense attorneys told Bridge Michigan they are skeptical.

“Everybody drives every day with anything from coffee, to a prescription to maybe an aspirin,” said Michael Nichols, an East Lansing attorney who specializes in DUI cases. “It's whether or not you're under the influence of a controlled substance.

“In the marijuana context… you can drive after using, you just can’t drive if you’re intoxicated or impaired. So many things could show up as positive for THC, but they're not THC.” 

BeGole’s proposal comes after pilot programs in Michigan of the tests, which involve using a handheld instrument with a mouth swab to test saliva. 

The SoToxa testing machines — which cost $6,000 apiece — can detect the presence of marijuana, amphetamines, opioids, cocaine and heroin within five minutes.

A House Fiscal Agency analysis of the pilot program found that the vast majority of tests for opioids and methamphetamines were negative, while more than half of tests were positive for THC.

That is a big drawback of the machines, according to a November research paper published by the University of Michigan’s Ford School of Public Policy.

“There are no industry standards for accuracy or sensitivity in the manufacture of these tests (and) incidences of false positives and negatives cast doubt on the accuracy of these tests,” the study found.

The lawmaker, BeGole, noted that the test is designed to help make the streets safer — not conclusively prove whether drivers are under the influence of marijuana.

“If the subject was arrested and transported to a more secure setting again, that would be where they would do the second collection of the oral fluid and then that would be placed in an evidential kit and … sent to the forensic laboratory for further examination,” BeGole said.

 “That's not something that the officer would know the results of right away. Usually, within 24 hours, they could get those results back. But those are the results that a prosecutor would use.” 

What other states are doing

The Indiana Police Department began using oral saliva test kits in December 2020, after the state purchased about 200 kits. 

Since then, 6,543 tests have been administered and nearly half — 3,173 — of the tests were positive for THC.  

“What was being seen on the road was not just what you would call your classic impaired driver of just alcohol,” said James Bryan, traffic safety director for the Indiana Criminal Justice Institute. 

“Now we live in a different time where there are multiple reasons that (a) driver may be impaired, whether it be from … THC, cocaine, methamphetamine, opiates, amphetamines, benzodiazepines.”

Bryan said in recent years he has seen more people driving impaired from a combination of drugs. 

“The officers were looking for … a way that could give them a fast, efficient test to help them establish probable cause for impairment,” he said. 

The Minnesota Police Department recently concluded its pilot of the use of oral testing kits and found that drugs were detected in over 87% of the tests, the most common being cannabis, methamphetamines and amphetamines.

“Sadly, the deadly seriousness of impaired driving goes beyond just alcohol,” said Mike Hanson, director of the Office of Traffic Safety in a press statement. 

“Advances in roadside technology will help law enforcement identify drug-impaired drivers and keep us all safe.”

But critics say accuracy questions have dogged the tests in states where they have been implemented.

“The goal of trying to make sure that people are not driving impaired is important,” said Justin Colacino, associate professor for the Department of Environmental Health Sciences at the University of Michigan. 

“My concern comes from the way that they might use these data to try to correlate the levels of THC in somebody's saliva with impairment,” Colacino said. 

“THC in one’s saliva doesn’t necessarily indicate someone is impaired because they could have ingested THC hours or even days prior to operating a vehicle, and it still shows up in their system despite the immediate effects of marijuana not being present in their system. “