If you fail a field sobriety test in Michigan, it’s not an automatic conviction. Not even close. Instead, it’s the piece of evidence an officer uses to establish probable cause—the legal justification they need to arrest you for Operating While Intoxicated (OWI).
Think of it as the green light for the officer to take things to the next level, not the final verdict.
The Immediate Aftermath of a Failed Field Sobriety Test
Failing one of those roadside "pop quizzes" kicks off a pretty predictable chain of events. It's the first domino that falls, turning a routine traffic stop into a full-blown criminal investigation. And while the test result itself is rarely the knockout punch in court, its role in getting you arrested is huge.
This is where things get disorienting. Once the officer decides you’ve "failed"—based on their own subjective opinion of how you did—the whole vibe of the stop changes. You'll likely be told you are under arrest for OWI, and from there, a series of steps begins to pull you deeper into the legal system.
The Arrest and What Follows
The moment of arrest is unmistakable. An officer will put you in handcuffs, read you your Miranda rights, and place you in the back of their patrol car. Just like that, your freedom is gone, and you’re officially in police custody.
While this is happening, the officer has to figure out what to do with your car. Depending on their department's policy and where you were stopped, your vehicle might be:
- Impounded: Towed to a lot where it will rack up daily storage fees you’ll have to pay.
- Secured on-site: Locked up and left on the side of the road, though this is less common.
- Released to a passenger: If you have a sober, licensed friend in the car, they might be allowed to drive it away.
After your car is dealt with, you’ll be driven to the local police station or sheriff's department for booking. This is where the next, and arguably more critical, part of the investigation kicks in: chemical testing.
This flowchart shows how the process typically flows after a roadside test.
As you can see, failing the test is what directly triggers the arrest and transport for an official chemical test.
The Unreliability of Field Sobriety Tests
Here’s something you absolutely need to know: FSTs are notoriously subjective and full of errors. These aren't scientific measurements. They're divided-attention exercises that plenty of sober people would have trouble with, especially on a dark road with cars flying by.
The whole legal reason for your arrest is based on these tests, yet their accuracy is shaky at best. This is often a major focus in a strong OWI defense.
The table below breaks down the three standardized tests and their official accuracy rates—even under perfect, laboratory-like conditions.
Standardized Field Sobriety Tests and Their Accuracy
| Test Name | What It Measures | NHTSA-Stated Accuracy Rate |
|---|---|---|
| Horizontal Gaze Nystagmus (HGN) | Involuntary jerking of the eyes when looking to the side. | 88% |
| Walk-and-Turn | Ability to follow instructions and maintain balance while walking heel-to-toe. | 79% |
| One-Leg Stand | Ability to balance, listen to instructions, and count out loud. | 83% |
Even the National Highway Traffic Safety Administration (NHTSA) admits these tests aren't perfect. And remember, those accuracy numbers are from controlled studies. Out on the road, with poor lighting, uneven ground, and officer error, the results become even less reliable.
That's why a "failed" test is just the beginning of the fight, not the end. You have rights, and the evidence against you might be weaker than it seems. Since these tests are voluntary, it’s also critical to understand when you can refuse a field sobriety test in Michigan to begin with.
Demystifying the 'Big Three' Field Sobriety Tests
When a police officer in Michigan suspects you’ve been drinking and asks you to step out of your car, they aren't just winging it. They’re about to run you through a series of exercises straight from a playbook created by the National Highway Traffic Safety Administration (NHTSA).
These are called "divided-attention" tests, and they’re designed to test both your mental and physical abilities at the same time.
It's crucial to understand that these aren't scientific measures of intoxication. Think of them more like roadside gymnastics. They are intentionally difficult, forcing you to listen, remember complex instructions, and perform specific physical movements all at once—a real challenge for anyone, even when completely sober.
The officer is trained to watch for very specific mistakes, which they call “clues.” Let’s break down exactly what they’re looking for.
The Horizontal Gaze Nystagmus (HGN) Test
This is almost always the first test you'll face. The Horizontal Gaze Nystagmus (HGN) test is all about your eyes. The officer will hold up a stimulus, usually a pen or their finger, and ask you to follow it with your eyes without moving your head.
"Nystagmus" is a medical term for the involuntary jerking of the eyeball, something that can become much more pronounced after consuming alcohol. The officer is looking for three clues in each eye, giving them a total of six possible points against you.
- Lack of Smooth Pursuit: Are your eyes bouncing or jerking as they follow the object, instead of moving smoothly?
- Distinct and Sustained Nystagmus at Maximum Deviation: When your eye is held all the way to the side, does it jerk noticeably for a few seconds?
- Onset of Nystagmus Prior to 45 Degrees: Does the jerking start before the object reaches a 45-degree angle from the center of your nose?
According to NHTSA, if the officer sees four or more clues, they're trained to believe your BAC is likely over the legal limit. The problem is, dozens of medical conditions, medications, and even just being tired can cause nystagmus.
The Walk-and-Turn Test
Next up is the classic Walk-and-Turn. The officer instructs you to take nine heel-to-toe steps along a straight line (which might just be an imaginary one), pivot in a very specific way, and then take nine heel-to-toe steps back.
The test has two parts: the instruction phase and the walking phase. The officer is watching for a total of eight possible clues. If you show just two or more of these clues, you've "failed" in their book.
The eight potential clues for failure include:
- Losing your balance while the officer gives instructions.
- Starting the test before they're done talking.
- Stopping while walking to try and regain your balance.
- Failing to touch your heel to your toe (with a gap of more than half an inch).
- Stepping off the line.
- Using your arms for balance (raising them more than six inches).
- Making an improper turn.
- Taking the wrong number of steps.
The One-Leg Stand Test
The final standardized test is the One-Leg Stand. You'll be told to raise one foot about six inches off the ground and count out loud—"one-thousand-one, one-thousand-two…"—for about 30 seconds or until the officer says stop.
This test is supposed to check your balance and ability to follow directions. The officer is looking for four specific clues of impairment:
- Swaying while you try to balance.
- Using your arms to keep from falling.
- Hopping on your anchor foot.
- Putting your raised foot down.
Just like the Walk-and-Turn, if the officer sees two or more of these clues, it's marked down as a failure. You can dive deeper into the specifics of the three tests commonly used for field sobriety tests and what each one entails.
Here’s the reality: these tests are notoriously unreliable. NHTSA's own studies found the Walk-and-Turn test is only 68% accurate. That means 32% of sober people fail it. Factors like age, physical injuries, weight, poor footwear, and simple nerves can all lead to a "fail." This is exactly why a failed test can—and should—be challenged in court.
Why Sober People Fail Flawed Sobriety Tests
It’s a huge myth that only drunk people fail field sobriety tests. I’ve seen it countless times—these tests are practically designed to trip up perfectly sober individuals.
Think about it. You’re on the side of a dark road, traffic is flying by, and a police officer is asking you to perform what amounts to a high-stakes gymnastics routine. That kind of pressure alone is enough to make anyone look clumsy, regardless of what they’ve had to drink.
Sometimes, a simple misunderstanding can put you in this spot. Maybe you were seen drinking something that just looked like alcohol. That’s why it’s good to know the rules around things like, can you drink non-alcoholic beer while driving. A harmless choice can quickly spiral into a stressful roadside encounter where you’re trying to prove you’re sober by performing these flawed physical challenges.
When someone "fails" a field sobriety test, it often has nothing to do with being impaired. It has everything to do with the bad science behind the tests and all the other factors at play.
Medical And Physical Conditions Can Mimic Impairment
Your own body can work against you during these tests. A lot of medical conditions have symptoms that look exactly like the "clues" of intoxication officers are trained to spot.
- Inner Ear Problems: If you suffer from something like vertigo, your balance is already compromised. Forget trying to do the Walk-and-Turn or One-Leg Stand test successfully.
- Neurological Disorders: Any condition that impacts your motor skills, coordination, or even your eye movements can make you appear impaired to an officer.
- Past Injuries: That old knee or back injury you have? It can make balancing on one leg or walking a straight line incredibly difficult, if not painful.
- Physical Traits: Even the government’s own research admits that people who are 50 or more pounds overweight or over the age of 65 will struggle with these balance tests.
The officer giving the test isn't a doctor. They can't tell the difference between a medical symptom and actual impairment, and that confusion often leads to a wrongful arrest.
Environmental And Psychological Pressures
The side of the road is nothing like the quiet, controlled lab where these tests were first studied. It's a chaotic and intimidating place, and that environment seriously messes with your ability to perform.
Let’s talk about the numbers. According to the National Highway Traffic Safety Administration's (NHTSA) own data from the 1970s, the One-Leg Stand test is only 65% accurate. That means a staggering 35% of sober people fail even under ideal lab conditions. Other studies have shown failure rates as high as 41%. Now, add in real-world factors like wind, poor lighting, or just being tired—things the lab stats don't account for—and your chances of "passing" drop even more.
Just think about the scene of your traffic stop. Was it dark? Were you standing on a sloped gravel shoulder? Were police lights and oncoming headlights blinding you?
On top of all that, there’s the psychological pressure. Most people get extremely nervous and anxious when pulled over. That fear can cause shaking, confusion, and make it tough to follow the officer’s complicated instructions. This isn't a sign of guilt—it's a normal human reaction to a stressful situation. When you add it all up, it's pretty clear that failing a field sobriety test in Michigan might say more about the test itself than it does about you.
From Roadside Arrest to Station House Chemical Tests
Once an officer decides you’ve failed a field sobriety test, everything changes in an instant. The handcuffs click, and you’re no longer just pulled over on the side of the road—you’re under arrest and heading to the police station. This is where things get serious, and a powerful state law takes over.
That law is called Implied Consent. You can think of it as an agreement you made the day you got your Michigan driver's license. By accepting the privilege to drive on Michigan roads, you automatically agreed to take a chemical test—breath, blood, or urine—if an officer ever lawfully arrests you for drunk driving.
Refusing the voluntary field sobriety tests on the roadside is one thing; there's no penalty for that. But refusing the mandatory chemical test at the station? That's a completely different ballgame with its own severe and immediate consequences.
The Two Breath Tests: A Critical Difference
At the station, the officer will read you your chemical test rights. Then they’ll ask you to provide a breath sample, usually on a big, stationary machine like the Intoxilyzer 9000. This is the official test, the one the prosecutor wants to use as evidence against you in court.
It’s incredibly important to know the difference between the two breath tests you might face:
- Preliminary Breath Test (PBT): This is the small, handheld device the officer might offer you on the roadside. In Michigan, refusing this is just a civil infraction, like a ticket. The results can't be used in court to prove you're guilty, only to give the officer probable cause for an arrest.
- Evidentiary Breath Test (DataMaster/Intoxilyzer): This is the official, more accurate test at the police station. The results from this machine are absolutely admissible in court as proof of your Blood Alcohol Content (BAC). This is the test that falls under Michigan’s Implied Consent law.
Think of the PBT as a pop quiz, while the test at the station is the final exam that goes on your permanent record. One has minor consequences for saying no, the other has major ones.
The Steep Price of Refusing the Chemical Test
If you refuse the official chemical test at the station, you’re immediately hit with the penalties from the Implied Consent law. These consequences are automatic, and they happen completely separately from your criminal OWI case.
When you refuse, the officer files a "Report of Refusal" with the Michigan Secretary of State, which kicks off an administrative process against your driver's license. For a first-time refusal, the penalties are:
- An automatic one-year suspension of your driver's license.
- Six points added to your driving record.
This license suspension has nothing to do with any suspension you might get later if you're convicted of OWI. Even if your criminal case gets thrown out, you still lose your license for a year just for the refusal. You only have 14 days from your arrest to challenge this suspension. You can learn more about this critical process and what happens if you refuse by exploring the details of Michigan’s Implied Consent law.
Your Right to a Second Opinion
There's one more vital piece of the puzzle you need to know. If you agree to take the police department's chemical test, Michigan law grants you a crucial right in return: the right to get your own, independent test.
After you provide your sample for the police, you can request to have your own blood test done at a hospital or other medical facility, at your own expense. The police are required to give you a reasonable opportunity to make that happen. This is a huge deal. It gives you the chance to get a second BAC reading, and if it differs significantly from what the police test showed, it could become a powerful piece of evidence for your defense.
Building Your Defense by Challenging the FST
Just because an officer claims you “failed” a field sobriety test and put you in handcuffs for an OWI doesn’t mean your case is a lost cause. Honestly, for a defense attorney who knows what they’re doing, this is where the real work begins. A failed FST isn't some undeniable proof you were drunk—it's a subjective opinion from an officer, and it’s often full of holes. A solid defense strategy starts by taking apart the very FST results that led to your arrest.
Think of it this way: the prosecutor's case is like a house, and the FSTs are the foundation. They're what the officer used as probable cause to justify your arrest. If your attorney can show that foundation is cracked and unstable, the whole case against you can come crashing down. This isn't about magic tricks; it's about digging into every single detail of the traffic stop and how those tests were actually given.
A good attorney doesn't see a "failed" FST as a fact. They see it as a claim that has to be proven, and that perspective opens up a ton of opportunities to fight the charges and protect your freedom.
Scrutinizing the Officer’s Every Move
The first place we almost always look is at the officer's conduct. The National Highway Traffic Safety Administration (NHTSA) has incredibly strict, standardized rules for how these tests are supposed to be explained and demonstrated. Any slip-up, no matter how minor it seems, can make the results totally unreliable.
An experienced OWI defense lawyer will immediately go after all the evidence—dash-cam video, body-cam footage, and the police report. They’ll review this stuff frame-by-frame, asking some really pointed questions:
- Were the instructions read word-for-word? Officers are required to give instructions exactly as written by NHTSA. If they add, skip, or change words, it can easily confuse someone and mess up the test.
- Was the test done on a proper surface? The Walk-and-Turn and One-Leg Stand tests need to be done on a surface that is reasonably dry, hard, level, and not slippery. Doing them on a sloped gravel shoulder or in the pouring rain is a major violation of the rules.
- Did the officer demonstrate the test correctly? If the officer’s demonstration was sloppy, it's not fair to expect you to perform it perfectly. You might have done it wrong through no fault of your own.
- Were environmental factors ignored? Think about it. Blinding police lights, cars whizzing by, wind, and freezing cold can all throw off your balance and concentration. A good officer notes these things; a bad one ignores them.
By pointing out these mistakes, an attorney isn't just making excuses. They are showing that your "failure" had more to do with the officer's bad procedure than any supposed impairment.
Introducing Your Side of the Story
Another huge part of the defense is showing that something other than alcohol caused you to "fail" the FSTs. Like we've covered, a long list of medical, physical, and even mental health issues can make it nearly impossible for a completely sober person to pass these coordination tests.
Your attorney can build a case to explain why you performed the way you did. This might involve bringing in:
- Medical Records: We can use documents to show you have conditions like an inner ear disorder, vertigo, neurological problems, or old injuries to your legs, back, or neck.
- Expert Testimony: A medical expert can testify and explain to the judge or jury how your specific health issue creates the exact same "clues" of impairment the officer was looking for.
- Personal Testimony: We can also just explain the obvious. NHTSA itself admits that being significantly overweight or over 65 years old can throw off the test results.
When you provide a legitimate, non-alcohol-related reason for your performance, you completely change the story. It’s no longer about being "impaired"—it's about being physically unable to perform a roadside gymnastics routine.
The Ultimate Goal: Suppressing the Evidence
The strategic endgame of attacking the FST is often to file a motion to suppress. This is a legal move where we argue that since the FSTs were unreliable, the officer never really had the probable cause needed to legally arrest you. If the judge agrees, the arrest gets thrown out. And here's the best part: that means all the evidence collected after the illegal arrest—including the much more damaging chemical test from the breathalyzer or blood draw at the station—gets kicked out of court, too.
Your Action Plan After a Michigan OWI Arrest
The flashing lights are gone, the handcuffs are on, and your mind is probably racing a mile a minute. It's a confusing and scary place to be. But what you do in the hours and days right after a Michigan OWI arrest is absolutely critical. Staying calm and taking the right steps can make a massive difference in how your case unfolds.
First things first: you have the right to remain silent, and you need to use it. After you've given your name and identification, that's it. You don't have to answer questions about where you were, what you drank, or anything else. Just politely and firmly say, "I am going to remain silent, and I want to speak with my lawyer." Don't try to explain or argue—just stop talking.
Preserve Key Details Before They Fade
As soon as you possibly can, grab a pen and paper and write down everything you can remember. Your memory is evidence, but the stress of an arrest makes details fade fast. Getting it all on paper right away is one of the smartest things you can do for your defense.
Try to jot down notes on things like:
- The Stop: What reason did the officer give for pulling you over in the first place? What were their first questions?
- The FSTs: Which roadside tests did they have you do? What were their exact instructions? Did you feel you performed them correctly?
- The Environment: Think about the conditions. Was it dark, windy, or raining? Was the road surface uneven, sloped, or covered in gravel? Small details matter.
- Your Condition: Were you exhausted, sick, or just plain nervous? Do you have any old injuries or medical issues that might affect your balance or coordination?
What might seem like a tiny, insignificant detail can sometimes become the key to challenging the officer’s reason for arresting you.
The chaos of an arrest can make you want to talk your way out of it. Don't. Your only job is to protect yourself. That means no admissions, no arguments, and no consenting to searches. Your focus needs to shift immediately to two things: documenting the facts and getting a lawyer.
Take Immediate Legal Action
After an OWI arrest, the clock starts ticking—fast. You have some very tight deadlines, especially when it comes to your driver's license. Your first phone call should be to a defense lawyer who lives and breathes Michigan OWI cases. A good lawyer can get to work right away protecting your rights and your driving privileges.
Part of your immediate plan is figuring out how to get released from jail. For those dealing with this outside of Michigan, other resources can explain the general process. For example, you can find a helpful guide on how to get a bond for DUI that breaks down the costs and steps involved.
An experienced OWI attorney will walk you through what's coming next, starting with your arraignment (your first day in court). They'll dig into every piece of evidence—from the police report to the dash-cam video—and start building a defense based on the unique facts of your case. Don't wait. Taking immediate action is the only way to get some control back and start fighting the charges.
Frequently Asked Questions About Michigan FSTs and OWI
Even after walking through the whole process, you're bound to have more questions. The moments during and after a traffic stop are confusing, and it's normal to feel like you're missing key pieces of information.
Let's clear up some of the most common things people ask after being pulled over for a suspected OWI in Michigan. Getting straight answers can make all the difference when you have to make a quick decision.
Can I Legally Refuse to Take a Field Sobriety Test in Michigan?
Yes, absolutely. In Michigan, you have every right to politely say "no" to field sobriety tests. Think of the walk-and-turn, the one-leg stand, or the eye test—they are all completely voluntary.
This is a critical distinction. Refusing a chemical test after you’ve been arrested has serious consequences, but there are no direct legal penalties, like an automatic license suspension, for declining to perform an FST on the side of the road. An officer might still arrest you based on other things they observed, but you don't have to give them more subjective evidence to use against you.
If FST Results Are Not Used at Trial Why Do They Matter?
This is a point that trips a lot of people up. While your "performance" on an FST usually can't be used in a Michigan courtroom to prove you were drunk, it’s still incredibly important. The FST is the main tool an officer uses to build "probable cause" to arrest you in the first place.
A lawful arrest is the gateway to everything that follows. If the arrest wasn't legal, then any evidence gathered after it—including that all-important chemical test result—can be thrown out.
That's why a huge part of a strong OWI defense is attacking the validity of the FST. If we can show the test was administered improperly or that your performance was affected by something other than alcohol, we can argue the officer never had the grounds to arrest you. This can get the entire case dismissed.
What Is the Difference Between a PBT and the DataMaster Breath Test?
It's easy to get these two confused in the heat of the moment. The Preliminary Breath Test (PBT) is the small, handheld device the officer asks you to blow into on the roadside. PBT results are not admissible in court to prove your guilt, but they can be used to help establish probable cause for an arrest.
The DataMaster (or sometimes an Intoxilyzer) is the big, official machine back at the police station. This is the evidentiary breath test, and its results are what the prosecutor will rely on in court as proof that your BAC was over the legal limit.
What Happens to My License Immediately After an OWI Arrest?
If you agree to the chemical test at the station and your BAC is over the legal limit, the officer will typically take your physical driver's license right then and there. They'll hand you a temporary paper permit that allows you to keep driving for a short time.
But if you refuse that chemical test, the consequences are immediate and severe. You're looking at an automatic one-year license suspension under Michigan's Implied Consent law. You only have 14 days from the date of your arrest to file an appeal and fight that suspension. Acting quickly with an experienced attorney is crucial to protect your ability to drive.
An OWI arrest puts your freedom, finances, and future on the line. At David G. Moore, Attorney at Law, we know how to navigate the complexities of Michigan's drunk driving laws. We have the experience to challenge every piece of evidence, from a poorly-given field sobriety test to an improperly calibrated breathalyzer. You don’t have to face this alone. Schedule a consultation today at https://dgmoorelaw.com to start protecting your rights.
