Field sobriety tests in Michigan are roadside assessments that law enforcement officers use to evaluate whether a driver may be impaired by alcohol or drugs during a traffic stop. These standardized tests, developed by the National Highway Traffic Safety Administration (NHTSA), assess balance, coordination, and cognitive function. While field sobriety test results are not conclusive proof of intoxication, they can establish probable cause for an arrest on operating while intoxicated (OWI) or operating while visibly impaired (OWVI) charges. Knowing how these tests work, what your rights are, and how results can be challenged is essential for anyone facing an OWI investigation.
At Michigan Defense Law, Oakland County criminal defense lawyer Paul J. Tafelski represents clients facing drunk driving charges throughout Oakland County and the surrounding areas. Our OWI defense attorneys review how field sobriety tests were administered, identify errors in the testing process, and develop defenses tailored to your case.
This guide explains how field sobriety tests work in Michigan, when officers use them, and how these test results may be challenged. Contact us at (248) 451-2200 to schedule a free consultation.
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If law enforcement pulls you over on suspicion of being under the influence of alcohol, a controlled substance, another intoxicating substance, or a combination of these, the officer may ask you to consent to taking one or more standardized field sobriety tests (SFSTs). SFSTs are designed to see if you act intoxicated.
Under MCL 257.62a, Michigan law defines a “standardized field sobriety test” as one of the tests “validated by the National Highway Traffic Safety Administration.” This statutory definition is significant because it establishes that only tests administered in substantial compliance with NHTSA standards qualify as standardized field sobriety tests under Michigan law. A test that does not meet this standard may not be admissible as an SFST, regardless of what the officer observed.
While SFSTs are not conclusive proof of intoxication, they can be used as probable cause to make an arrest for drunk driving charges like operating while intoxicated (OWI) or operating while visibly impaired (OWVI). These are two of the primary drunk driving offenses in Michigan. If you are arrested, an officer will request a chemical test to determine your blood alcohol content (BAC). A BAC of 0.08 or higher can result in an OWI charge, while a BAC of 0.17 or above triggers Michigan’s high BAC offense with more severe penalties.
Not just any officer can testify about SFST results in Oakland County courts or anywhere else in Michigan. Under MCL 257.625s, a person who testifies about standardized field sobriety test results, including horizontal gaze nystagmus (HGN) testing, must be “qualified by knowledge, skill, experience, training, or education” in the administration of those tests.
This means the prosecution must lay a proper foundation showing the officer is qualified by knowledge, skill, experience, training, or education before the officer may testify about SFST results.
Officers sometimes ask drivers to perform tests beyond the three NHTSA-validated SFSTs. These non-standardized tests include:
While these tests have not been validated by NHTSA, they are still admissible in Michigan courts if the prosecution establishes a proper evidentiary foundation. Michigan’s 2016 Public Act 242 clarified that the standardized test framework under MCL 257.62a does not preclude the admissibility of non-standardized field sobriety tests that comply with the Michigan Rules of Evidence.
Key Takeaway: Michigan law under MCL 257.62a defines SFSTs as NHTSA-validated tests administered in substantial compliance with NHTSA standards. Officers must be qualified under MCL 257.625s to testify about results, and non-standardized tests may also be admitted with a proper foundation.
If you have questions about whether the tests used in your case met Michigan’s legal standards, contact Paul J. Tafelski at (248) 451-2200 to discuss your situation.
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There are three standardized field sobriety tests used in Michigan OWI investigations. All of them were originally developed by the National Highway Traffic Safety Administration and are the tests recognized under MCL 257.62a.
Horizontal gaze nystagmus (HGN) is an involuntary jerking of the eyes that officers check while a person follows a moving object, such as a pen. Under NHTSA’s standardized testing procedures, the officer looks for three clues in each eye: lack of smooth pursuit, distinct and sustained nystagmus at maximum deviation, and onset of nystagmus before 45 degrees.
Because each eye is checked separately, the maximum number of HGN clues is six. NHTSA says that four or more clues may indicate a BAC at or above 0.08 when the test is administered in a standardized manner.
It can be difficult for intoxicated people to walk in a straight line and turn. In a walk-and-turn test, aside from testing the ability to perform the action itself, the person’s ability to listen to, comprehend, and follow simple instructions is also a subject of the test. The test includes instructions to, for example, take a certain number of steps in a straight line.
Law enforcement looks for specific signs of intoxication, including whether the person can keep their balance while listening to instructions, whether they need to stop or use their arms to keep their balance, whether they lose their balance while turning to retrace their steps in the opposite direction, and whether they take the number of steps they were asked to.
People who are intoxicated, because their balance, coordination, and concentration are often affected, may find it difficult to stand on one leg. The one-leg stand test asks the person to stand on one foot while keeping the other foot roughly six inches off the ground. They are asked to do thousand counts (saying “one thousand one, one thousand two,” and so on) for 30 seconds while standing this way.
Law enforcement will look at several factors during the test, including whether the person sways, needs to use their arms for balance, needs to hop to remain standing, or puts their foot on the ground.
| Test | What Officer Observes | Clues That Count | Common Defense |
|---|---|---|---|
| HGN | Eye movement tracking a stimulus | Lack of smooth pursuit, nystagmus at max deviation, onset before 45° | Improper administration, medical condition, unqualified officer |
| Walk and Turn | 9-step heel-to-toe walk and turn | 8 scored clues including balance during instructions, wrong steps, arms raised | Surface conditions, footwear, officer deviation from NHTSA protocol |
| One-Leg Stand | 30-second single-foot balance | 4 scored clues: sway, arms, hop, foot down | Medical condition, footwear, officer error in timing or instruction |
Key Takeaway: Each standardized field sobriety test has specific scoring clues, and each may be challenged if the officer did not follow proper procedures.
When a law enforcement officer administers standardized field sobriety tests, they document every clue they observe. That documented clue count becomes part of the prosecution’s evidence at trial. The officer’s SFST observations also serve as the primary basis for establishing probable cause for an OWI arrest.
The prosecution may also rely on the officer’s training and testimony to support the admissibility of SFST evidence.
The Michigan Court of Appeals addressed the admissibility of HGN evidence in People v. Berger, 217 Mich. App. 213; 551 NW2d 421 (1996). The court held that HGN is scientific evidence that has general acceptance and reliability, but only if “the test was properly administered by a qualified person.”
Under People v. Berger, HGN evidence is usually challenged in two main ways: by arguing that the officer did not administer the test correctly or that the officer was not qualified to administer it. Each challenge depends on the facts of the case.
Michigan law requires standardized field sobriety tests to be administered in substantial compliance with NHTSA standards. If an officer skips steps, gives the wrong instructions, or otherwise departs from the standardized procedure, the defense can argue that the SFST evidence should be excluded or given less weight.
I wanted to say thank you for representing me this week. I could not be happier with the outcome. I truly realize how significant the impact of my situation is going to be the rest of my life. People make mistakes but people do change. You were a great supporter, open, candid and very honest. I felt like you really cared about the outcome of my case. I will gladly pass your name along to anyone I know who is seeking legal assistance for a DUI.
Paul J. Tafelski has practiced law in Michigan for over 20 years, focusing on criminal defense and OWI/DUI matters. He earned his undergraduate degree from Michigan State University and received his Juris Doctor from the Michigan State University College of Law.
He is admitted to practice law in Michigan and is a member of several professional organizations, including the State Bar of Michigan, the American Bar Association, the Criminal Defense Lawyers of Michigan, and the Oakland County Bar Association.
Mr. Tafelski has been recognized as one of Michigan’s top criminal defense lawyers by Super Lawyers (2011-2013, 2017-2026) and was named a Leading Lawyer in 2017. Throughout his career, he has represented a wide range of clients in OWI and criminal defense, guiding cases from early proceedings through trial. His approach emphasizes steady preparation and a focus on helping clients move forward with their cases.
Unfortunately, the elements law enforcement officers are trained to see as signs of intoxication are not necessarily always caused by intoxication. People who have difficulty standing, for example, might have a number of medical conditions, including arthritis, artificial limbs, balance problems caused by inner ear issues, and more. Neurological conditions can cause eye impairments resembling HGN. Certain medications can also cause HGN issues, balance problems, and even difficulty concentrating on counting.
Medical conditions and physical factors that can produce false SFST clues include:
As a result, an SFST could put you on the road to a serious OWI charge merely because of a medical condition or a pharmaceutical treatment prescribed by your doctor. In addition, law enforcement officers are specifically trained on these tests, but an officer may lack experience, may not have administered the tests in a long while, or may simply not perform them correctly. The conclusions can be incorrect if any of these factors are present.
Key Takeaway: Many medical conditions, neurological disorders, and medications can cause a person to display SFST clues without any alcohol or drug impairment. These factors are a common and effective basis for challenging field sobriety test results.
I didn’t know much about the entire legal process so Paul was a great Lawyer for me. He took the time to explain everything without making me feel dumb. He fought for me and got me a great outcome for my case. He is a great guy that eased my stress about my case and I would recommend him to anyone. Thank you Paul!
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Yes. There are established legal pathways to challenge field sobriety test results in Michigan. The *People v. Berger* decision and the requirements of MCL 257.625s give defense attorneys two primary avenues for attacking SFST evidence: improper test administration and officer qualification deficiencies.
NHTSA has detailed protocols for administering each of the three standardized tests. When an officer deviates from those protocols, the test results become unreliable and potentially inadmissible.
Common officer errors during SFST administration include:
An experienced OWI defense attorney will obtain the officer’s dashcam or bodycam footage and compare the actual administration against NHTSA standards. Any deviation can form the basis for a motion to suppress the test results.
Defense challenges to an officer’s qualifications should track the statute. Relevant facts may include the officer’s training, experience administering the tests, and ability to explain the NHTSA procedure in court.
An officer who completed SFST training years ago and has rarely administered the tests since may not meet the qualification threshold required by Michigan law. If the court determines the officer was not qualified, the SFST testimony is inadmissible.
Key Takeaway: Michigan field sobriety test results can be challenged on two grounds: the officer did not follow NHTSA administration protocols, or the officer was not sufficiently qualified. Both challenges can lead to suppression of the test evidence.
Michigan’s implied-consent statutes apply to post-arrest chemical tests, and Michigan law separately makes refusal of a preliminary breath test (PBT) a civil infraction. Michigan law does not create those same automatic civil or license penalties for refusing a standardized field sobriety test. But refusal does not end the investigation. An officer may still rely on other observations to decide whether there is probable cause to arrest, and a prosecutor may try to use the refusal to argue consciousness of guilt. Michigan’s statutory protection against using refusal evidence under MCL 257.625a(9) applies only to chemical tests, and courts have not extended that protection to field sobriety tests.
Your refusal should be polite and respectful to the law enforcement officer. Never argue with officers who are questioning you or have pulled you over. Refusing SFSTs is different from refusing a PBT or a chemical test, both of which carry separate penalties. A PBT refusal is a civil infraction with a fine of up to $150, and a chemical test refusal triggers a one-year license suspension and six points on your driving record under Michigan’s implied consent law.
Key Takeaway: You can refuse a standardized field sobriety test in Michigan with no criminal penalties or license sanctions. However, prosecutors may try to use refusal as evidence, and officers can still build probable cause through other observations. PBT and chemical test refusals carry separate, distinct penalties.
If you were charged and arrested on the basis of a failed SFST, it’s prudent to call an experienced Michigan OWI defense attorney. There are a number of potential defenses, depending on the circumstances and your situation, including medical reasons and improper law enforcement conduct.
Here are the steps you should take after failing a field sobriety test:
Even if you were arrested after a field sobriety test, a Michigan OWI lawyer can review the stop, the testing process, and the other evidence to determine what defenses or mitigation arguments may be available.
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Being charged with OWI after a field sobriety test can be stressful, especially if you believe the test results do not accurately reflect your level of impairment. You deserve an attorney who will scrutinize every detail of how those tests were administered.
Paul J. Tafelski has over 20 years of experience defending OWI cases in Oakland County and throughout Michigan. Our OWI defense lawyers take a close look at the evidence, assess officer qualifications, and determine what defenses may be available in your case.
Call Michigan Defense Law at (248) 451-2200 to schedule a free consultation. Our office is located at 2525 S Telegraph Rd, Suite 100, Bloomfield Hills, MI 48302, and we serve clients throughout Oakland County and the state of Michigan.
No. In Michigan, field sobriety tests are generally voluntary. Refusing them does not carry the same automatic penalties that can apply to refusing a preliminary breath test or a post-arrest chemical test.
NHTSA’s field validation materials state that the three-test SFST battery produced correct arrest decisions 91% of the time in the San Diego validation study when the tests were administered in a standardized manner. In those same NHTSA materials, HGN is listed at 88% accuracy, walk-and-turn at 79%, and one-leg stand at 83%. These are screening tools, not conclusive proof of intoxication, and their value depends heavily on proper, standardized administration.
Yes. A person may appear to “fail” a field sobriety test for reasons unrelated to alcohol or drugs. Balance issues, eye conditions, neurological problems, injuries, and even certain medications can affect performance.
Refusing a field sobriety test does not automatically end the stop. An officer may still rely on other signs of impairment, such as driving behavior, speech, or odor, and may still decide to make an arrest. SFST refusal does not trigger an automatic license suspension by itself.
Yes. A court may exclude field sobriety test evidence if the officer did not follow the required procedures or if the prosecution cannot show the officer was qualified to administer the test properly.
The HGN test is the eye test officers use during a DUI stop. While the driver follows a moving object, the officer watches for certain types of involuntary eye movement that NHTSA associates with impairment. Other medical or physical factors may also affect the result.
It can still create problems, even without automatic penalties. A prosecutor may argue that the refusal suggests you were trying to avoid giving the officer more evidence, while the officer may rely on other observations to support the arrest.