Michigan lawmakers are pushing forward with a bill that would allow law enforcement to use roadside saliva tests to determine whether drivers are under the influence of drugs, including marijuana. That proposal has reignited concerns about racial profiling, scientific reliability, and whether these tests would create more harm than safety — especially for Black drivers already navigating a deeply flawed legal system.
The legislation, introduced by Rep. Brian BeGole, a Republican from Perry, would make Michigan the 25th state to allow officers to administer roadside oral fluid tests to screen for substances like marijuana, amphetamines, opioids, cocaine, and heroin. According to BeGole, “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.”
But for many Black communities in Michigan, where law enforcement already polices bodies with a heavier hand, adding saliva tests to the roadside stop toolkit feels less like safety and more like surveillance wrapped in a new machine.
The tool in question is the SoToxa mobile test — a $6,000 device that uses a mouth swab and returns results within five minutes. BeGole emphasized that the test wouldn’t be the final word. “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.” Those results would come back within 24 hours and serve as the evidence prosecutors rely on.
But questions continue to rise around whether these tools can be trusted to deliver justice or if they open yet another path to wrongful arrest and legal entanglement. A November report published by the University of Michigan’s Ford School of Public Policy raised flags. “There are no industry standards for accuracy or sensitivity in the manufacture of these tests,” it stated. The research pointed to incidents of false positives and negatives, concluding they cast doubt on the entire process.
State data shows that 230 people in Michigan lost their lives in drug-impaired crashes in 2023. That figure may seem to justify stricter roadside enforcement, but when enforcement mechanisms disproportionately affect Black drivers and rest on shaky scientific ground, safety becomes a selective privilege, not a public right.
Saliva tests for drugs are not the same as breathalyzers for alcohol. There is no agreed-upon legal limit for THC — marijuana’s psychoactive component — the way there is for alcohol. THC can remain in a person’s system long after its intoxicating effects have worn off, making it possible for a person to test positive without being impaired.
That nuance matters. Especially when the consequences include arrest, court dates, and potentially life-altering charges.
A House Fiscal Agency analysis of Michigan’s pilot program using SoToxa machines revealed mixed findings. While more than half of the tests were positive for THC, the majority of results for opioids and methamphetamines were negative. That data raises deeper questions about what substances are truly being targeted and who is most likely to be impacted by enforcement.
Indiana started using similar tests back in December 2020. Since then, 6,543 oral fluid tests have been administered. Nearly half — 3,173 — were positive for THC. Critics argue that those numbers shouldn’t be accepted at face value. THC in saliva doesn’t confirm intoxication; it confirms presence. That’s a distinction the courts are still navigating, and for many civil rights advocates, it’s a reason to pause, not proceed.
Last month, the Michigan Supreme Court ruled that the smell of marijuana alone no longer counts as probable cause to search a vehicle. That ruling directly challenged a 25-year-old precedent, signaling a new legal understanding in the era of marijuana legalization. “A warrantless search must be based on probable cause and the smell of marijuana is insufficient to support probable cause,” wrote Justice Megan Cavanagh for the majority. Cavanagh, who was joined by Justices Richard Bernstein, Elizabeth Welch, Kyra Harris Bolden, and Chief Justice Elizabeth Clement, added that smell alone could not justify further police action.
The court made clear that marijuana possession, within legal limits, is not a criminal offense — nor should it be treated like one. That case centered on a 2020 Detroit parole compliance check, where police claimed to smell burning marijuana coming from a parked Jeep Cherokee. Despite the vehicle’s occupants denying they had smoked, police ordered them out of the car. A handgun was later found under the passenger seat, leading to felony charges. The state’s highest court reversed those charges, stating that the presence of marijuana smell alone no longer provides a reasonable basis for police to conduct searches.
Cavanagh clarified that marijuana use and possession are still not permitted under every circumstance. Driving while under the influence of marijuana remains illegal. “Although the smell of marijuana is no longer sufficiently indicative of the presence of contraband or illegal activity, that does not mean that the smell of marijuana is irrelevant to developing probable cause concerning illegal activity,” she wrote.
Justice Brian Zahra dissented, stating that lower courts may have failed to account for other visible factors that could have established probable cause.
Still, this ruling underscores the shifting legal landscape and makes BeGole’s push for oral testing even more contentious. Police officers have already lost one long-relied-upon tool to justify stops and searches. Replacing that with rapid-response saliva tests could become the new pathway to circumvent probable cause — with communities of color bearing the brunt.
Marijuana laws have evolved, but the legal system’s treatment of Black drivers hasn’t always kept pace. Racial disparities in traffic stops, searches, and arrests have been documented across the country. Michigan is no exception. Adding a flawed testing device that delivers questionable results to that equation risks compounding injustice under the banner of road safety.
Even the framing of the bill reveals the tension. BeGole calls the device “just a tool.” But in a justice system where tools often double as weapons, Black Michiganders have reason to be skeptical. Tools, when misused or misunderstood, become traps.
That’s why lawmakers, researchers, and advocates alike must grapple with more than just road fatalities. They must ask who gets stopped. Who gets tested. Who ends up in court. Who loses jobs, custody, housing, or future opportunities because of a test that wasn’t built with precision, fairness, or context in mind.
If Michigan wants safer roads, it must also want a more equitable justice system. Technology can’t serve as a shortcut through the complex layers of substance use, public health, legal precedent, and civil rights.
Policing can’t rely on guesswork masked as science. And public policy can’t move forward without ensuring communities of color won’t be dragged backward.
Before Michigan decides whether roadside saliva testing becomes law, it owes the public a clearer, more honest conversation about the cost — not just in dollars, but in dignity.