Key points
- Michigan law lets only a certified drug recognition expert in a county participating in the State Police pilot program require a preliminary oral-fluid (saliva) test.[1]
- Refusing a lawfully requested roadside oral-fluid test is a civil infraction; commercial drivers who refuse also get a 24-hour out-of-service order.[2]
- Like the roadside breath test, the saliva result may support an arrest but is admissible only for narrow purposes, and taking it does not excuse the post-arrest chemical test.[3][4]
- The State Police report on the pilot says a roadside oral-fluid result, positive or negative, "does not determine if a driver is impaired or not impaired."[5]
Michigan law allows a roadside oral-fluid (saliva) drug test only in a narrow setting: a peace officer certified as a drug recognition expert, in a county taking part in the Michigan State Police roadside drug-testing pilot program, may require a "preliminary oral fluid analysis."[1] It is not a general power given to every officer, and the statute ties it to a pilot program rather than a permanent statewide system.[6][1]
This page covers the statutes, the two pilot phases the State Police reported on, the refusal penalty and what the results can and cannot be used for.
The two statutes
MCL 257.625t: the pilot program
MCL 257.625t says the State Police "may establish a pilot program in this state for roadside drug testing to determine whether an individual is operating a vehicle while under the influence of a controlled substance."[7] The State Police must develop a written policy for the program.[7] A pilot lasts 1 calendar year, its funding "is subject to appropriation," and the State Police must report to the Legislature's judiciary committees within 90 days after it ends.[6] The section was added by 2016 PA 243 (effective September 22, 2016), known as the "Barbara J. and Thomas J. Swift Law," and amended by 2020 PA 87 (effective June 11, 2020).[6][7]
MCL 257.625r: who may require the test, and when
Under MCL 257.625r(1), the officer must be a certified drug recognition expert in a participating county.[1] The officer must have reasonable cause to believe the person was operating a vehicle on a highway or place open to the public and that a controlled substance may have affected the person's ability to operate, or reasonable cause to believe the person had any amount of a Schedule 1 drug or cocaine in the body.[1] A certified drug recognition expert is "a law enforcement officer trained to recognize impairment in a driver under the influence of a controlled substance rather than, or in addition to, alcohol."[8]
For more on DREs and the evaluation they use, see the drug recognition experts guide.
Refusing the roadside saliva test
| Driver | Consequence of refusing a lawful request |
|---|---|
| Any driver | Civil infraction.[2] |
| Commercial motor vehicle driver | Civil infraction, plus a 24-hour out-of-service order; the driver must be advised of both.[2] |
The refusal rule for the saliva test is separate from the rules for the evidential chemical test after arrest. Refusing the officer's post-arrest blood, breath or urine test results in license suspension and 6 points, and police may seek a court order for a test.[9][10] See refusing a breath or blood test and the implied consent law guide.
How the result can be used
The saliva statute copies the structure of the preliminary breath test statute.[3][11]
- Arrest. A certified DRE in a participating county "may arrest a person in whole or in part upon the results of a preliminary oral fluid analysis."[3]
- Challenge to the arrest. The result is admissible in an OWI-type prosecution or administrative hearing to help the court or hearing officer decide a challenge to the validity of an arrest.[3]
- Rebuttal only. It may also be offered by the defendant or the prosecution to rebut specific cross-examination testimony about a mismatch between the roadside result and a blood or urine test.[4]
- No substitute for the chemical test. "A person who submits to a preliminary oral fluid analysis remains subject to the requirements of sections 625a, 625c, 625d, 625e, and 625f for purposes of chemical tests described in those sections."[4]
The PBT comparison is covered in the preliminary breath test guide.
The pilot programs
| Phase | Dates | Scope reported by the State Police |
|---|---|---|
| Phase I | Nov. 8, 2017 to Nov. 8, 2018 | Berrien, Delta, Kent, St. Clair and Washtenaw counties; 92 roadside oral-fluid tests.[12] |
| Phase II | Oct. 1, 2019 to Sept. 30, 2020 | 69 counties; 693 incidents, 661 roadside tests, 131 DREs from 65 agencies.[13] |
After Phase I, the pilot committee recommended expanding it for one year to all DREs in the state.[12] Both phases used the same instrument, now called the Abbott SoToxa Mobile Test System, which tests one saliva sample for six drug classes: amphetamine, benzodiazepines, cannabis (delta-9-THC), cocaine, methamphetamine and opiates.[14]
Status as of October 2026
This guide did not find an official source showing whether a third phase or a permanent program exists. The statute still limits the test to DREs "in a county participating in the roadside drug testing pilot program."[1] The statutes describe a pilot, and anyone relying on a claim that a program is active in a specific county should check it with an official source.
What a saliva result does and does not show
The State Police Phase II report is careful about the limits of the test. It says: "Oral fluid testing does not equal the 'Gold Standard' but has been found to be accurate for purposes of preliminary roadside testing."[5] And: "a Roadside Oral Fluid test result regardless of positive or negative does not determine if a driver is impaired or not impaired."[5]
The SoToxa cut-off for THC, set by the manufacturer, Abbott, is 25 ng/mL of oral fluid, and the report warns that oral-fluid values differ greatly from blood values, citing a study that equated about 1 ng/mL of THC in blood with about 44 ng/mL in oral fluid.[5] The report says the ng/mL level in oral fluid "is much different than the equivalent ng/mL in blood."[14]
Michigan has no numeric THC limit in the Vehicle Code.[15] The Impaired Driving Safety Commission, whose March 2019 report summarized the first pilot phase, recommended more research to develop and validate ways to assess cannabis impairment, which "may include SFSTs and oral fluid testing."[16] The THC blood tests guide explains the blood side, and the drug-impaired driving evidence guide covers how drug cases are proved.
Commercial drivers
For a commercial motor vehicle driver, the DRE must use the oral-fluid result to decide whether to order the driver out of service, and must order a commercial driver who refuses out of service.[17] The commercial OWI rules are in the commercial vehicle OWI guide.
Common misunderstandings
| Belief | What the law says |
|---|---|
| "Any officer can swab me." | Only a certified DRE in a county participating in the pilot may require the test.[1] |
| "Refusing the swab is a crime." | Refusal is a civil infraction.[2] |
| "A positive swab proves impairment." | The State Police report says a result does not determine whether a driver is impaired.[5] |
| "If I give saliva, I don't need to give blood." | The person remains subject to the implied-consent chemical-test rules.[4] |
Common questions
Do Michigan police use saliva drug tests at the roadside?
The statute authorizes a State Police pilot program and limits the test to certified drug recognition experts in participating counties. The pilot ran in five counties from 2017 to 2018 and in 69 counties from 2019 to 2020. This guide did not find an official source on whether any program is running as of October 2026.[6][1][12][13]
What happens if I refuse a roadside saliva test?
Refusing a lawfully requested preliminary oral-fluid analysis is a civil infraction. For a commercial motor vehicle driver it is also a civil infraction, the driver must be told that, and the refusal results in a 24-hour out-of-service order.[2]
Can a saliva test result be used to convict me?
The statute lets the result be used to help decide a challenge to the arrest, and to rebut certain cross-examination testimony about whether the roadside result matched a blood or urine test. It does not list proof of guilt as a purpose.[3][4]
Does a positive saliva test mean I was impaired?
The State Police Phase II report says a roadside oral-fluid result, regardless of positive or negative, does not determine whether a driver is impaired, and that oral-fluid testing does not equal blood testing, though it was accurate for preliminary screening.[5]
Sources
- MCL 257.625r(1) — Michigan Legislature
- MCL 257.625r(5), (8), (9) — Michigan Legislature
- MCL 257.625r(2), (3) — Michigan Legislature
- MCL 257.625r(2), (3), (4) — Michigan Legislature
- MSP Phase II report (January 2021) — house.mi.gov
- MCL 257.625t(1), (2), (5) — Michigan Legislature
- MCL 257.625t(1), (3) — Michigan Legislature
- MCL 257.625t(6)(a) — Michigan Legislature
- MCL 257.625a(6)(b)(i)–(v) — Michigan Legislature
- MCL 257.625d(1) — Michigan Legislature
- MCL 257.625a(2)(b)(i)–(iii) — Michigan Legislature
- MSP, "Oral Fluid Roadside Analysis Pilot Program" report (February 2019) — house.mi.gov
- MSP, "Oral Fluid Roadside Analysis Pilot Program – Phase II" report (January 2021) — house.mi.gov
- MSP, "Oral Fluid Roadside Analysis Pilot Program – Phase II" report (January 2021), p 4 — house.mi.gov
- MCL 257.625(1), (3), (8) — Michigan Legislature
- Impaired Driving Safety Commission, Report (March 2019), pp 14, 17 — State of Michigan
- MCL 257.625r(6), (7) — Michigan Legislature
This page is general legal information about Michigan law, published by the office of Attorney Shawn Haff. It is not legal advice and reading it does not create an attorney-client relationship. Laws change and every case turns on its own facts — check the sources linked above and talk to a licensed Michigan attorney about your situation. In an emergency, call 911. For confidential help with alcohol or drug use, the SAMHSA National Helpline is 1-800-662-4357.