If you were recently pulled over and asked to perform roadside tests, you are probably wondering whether what happened out there on the side of the road can actually be used against you. The answer is more complicated than most people realize, and understanding how field sobriety tests work, where they fall short, and how they are used in court could have a real impact on the outcome of your case. You do not have to figure this out alone.
At Nero DUI Defense, our team has spent years helping people across Wisconsin fight OWI charges, including cases built heavily on field sobriety test results. Whether you are facing a first offense or a more serious repeat charge, we are here to help you understand your rights and build the strongest possible defense.
Call us today at (715) 318-7000 for a free consultation.
What Are Field Sobriety Tests in a Wisconsin OWI Stop?
When a law enforcement officer suspects a driver may be impaired, they typically ask that driver to step out of the vehicle and perform a series of physical and cognitive tasks. These are known as field sobriety tests, and they are used to help officers evaluate whether there is probable cause to make an arrest for operating while intoxicated.
Wisconsin follows the same general framework used by law enforcement agencies across the country. Officers are trained to observe how a driver moves, follows instructions, and maintains balance, and then they use those observations to justify an arrest.
The Three Standardized Field Sobriety Tests
The National Highway Traffic Safety Administration developed a standardized battery of three tests that are the most widely used in OWI investigations:
- The Horizontal Gaze Nystagmus (HGN) test: The officer moves a pen or small light horizontally in front of your eyes and watches for involuntary jerking movements that can indicate impairment
- The Walk and Turn test: You are asked to walk heel-to-toe along a straight line, turn in a specific way, and walk back
- The One Leg Stand test: You are asked to lift one foot off the ground and hold it for about 30 seconds while counting aloud
These three tests are considered "standardized" because officers are supposed to administer them in a specific, consistent way. When they do not follow the proper protocol, the results can be challenged.
Why Officers Use Field Sobriety Tests During an OWI Investigation
Field sobriety tests give officers a way to gather observable evidence before deciding whether to make an arrest. Because a breath or blood test requires more formal procedures, officers use roadside tests as an early tool to build their case and document what they witnessed.
In Wisconsin, the results of these tests do not convict you on their own, but they can contribute to an officer's decision to arrest you and can later be presented as evidence by prosecutors. That is why what happens during the roadside stop matters so much, and why having an experienced Wisconsin OWI lawyer review those details is so important.
How Reliable Are Field Sobriety Tests Really?
This is where many people are surprised to learn the truth. Even under ideal conditions, field sobriety tests are far from foolproof. Studies used by NHTSA to validate these tests showed accuracy rates that many legal and scientific experts have criticized as overstated. The HGN test was found to be accurate roughly 77% of the time, the Walk and Turn test around 68%, and the One Leg Stand test approximately 65%.
That means a significant number of sober people could fail these tests. When you factor in real-world conditions, those numbers become even less reliable. Field sobriety tests are not scientific certainties. They are subjective observations made by one officer, often at night, on the side of a busy road, under stressful circumstances.
If you believe you did not perform as well as you should have, or if you have questions about what the officer observed, call Nero DUI Defense at (715) 318-7000. We can help you understand what that evidence actually means.
What Can Affect Field Sobriety Test Results?
Medical, Physical, and Environmental Factors
One of the most important things to understand is that failing a field sobriety test does not automatically mean you were impaired. A wide range of factors can cause someone to perform poorly even when they are completely sober:
- Medical conditions such as inner ear disorders, neurological conditions, or back and leg injuries can make balance tests nearly impossible to pass
- Age and weight can significantly affect a person's ability to complete physical tasks like standing on one leg
- Fatigue, nervousness, or anxiety, especially the natural stress of being pulled over by police, can affect coordination and focus
- Prescription medications can cause eye movements similar to those observed in the HGN test
- Poor road conditions, uneven pavement, gravel, or wet surfaces can make the Walk and Turn test unreliable
- Inadequate lighting or bad weather can affect both your performance and the officer's ability to observe accurately
- Ill-fitting shoes or footwear that is not suitable for balance tests can skew results
Any one of these factors could lead to a poor performance that has nothing to do with alcohol or drug impairment. A skilled OWI defense attorney will look closely at all of these variables.
Can You Refuse Field Sobriety Tests in Wisconsin?
Yes. In Wisconsin, field sobriety tests are not legally required, and you have the right to decline them without facing an automatic license suspension. This is different from chemical tests like breath or blood draws, which fall under Wisconsin's implied consent law.
That said, refusing field sobriety tests does not mean the stop ends there. The officer may still arrest you based on other observations, such as the smell of alcohol, slurred speech, or erratic driving. And refusal can sometimes be noted in a police report and brought up later.
There is no single right answer about whether to refuse. The best thing you can do if you are ever in that situation is to be calm, be polite, and contact a Wisconsin OWI lawyer as soon as possible. If you have already been through a stop and are now facing charges, call us at (715) 318-7000 so we can evaluate what happened.
How Prosecutors Use Field Sobriety Tests in OWI Cases
Prosecutors often present field sobriety test results as concrete proof of impairment, even though the tests are highly subjective. They may rely on the officer's written report and in-court testimony describing every perceived misstep, hesitation, or stumble during the roadside evaluation.
In many cases, there is also dashcam or bodycam footage that captures the tests. This can actually work in your favor, since video sometimes tells a very different story than the officer's written account. An experienced defense attorney will review all available footage carefully. Whether you are dealing with a first offense OWI or a second or third offense, the stakes are real and the details matter.
How Defense Attorneys Challenge Field Sobriety Test Evidence
Officer Error and Subjective Judgments
Field sobriety tests leave a great deal of room for human error, and a strong defense often starts by examining exactly how the tests were administered. Some of the most common grounds for challenging this evidence include:
- The officer did not follow NHTSA standardized procedures when giving instructions or demonstrating the tests
- The officer failed to ask about medical conditions, injuries, or disabilities before administering physical tests
- The testing surface was uneven, wet, or otherwise unsuitable
- The lighting was poor or the conditions were unsafe for roadside testing
- The officer's observations were vague or inconsistent with available video footage
- The scoring was subjective and based on minor issues that a sober person might also exhibit
Beyond procedural errors, defense attorneys can also bring in expert witnesses to challenge the scientific reliability of field sobriety tests themselves. Courts in Wisconsin have recognized that these tests have meaningful limitations, and juries are not required to treat an officer's observations as definitive proof of impairment.
For a deeper look at how Wisconsin OWI law works and what defenses may be available to you, visit our Wisconsin OWI defense overview.
Why Calling a Wisconsin OWI Lawyer Early Can Make a Difference
The decisions you make in the days immediately following an OWI stop can shape everything that comes after. Evidence can be preserved or lost. Witnesses can be contacted or forgotten. Deadlines for challenging a license suspension can pass quickly.
At Nero DUI Defense, we have worked with clients across western Wisconsin who felt like the evidence was stacked against them, only to find that a careful review of the field sobriety test procedures, the officer's training record, and the available footage revealed serious problems with the prosecution's case. We take the time to understand exactly what happened during your stop and build a defense based on the real facts, not assumptions.
Whether you are facing a fourth offense OWI, a fifth or sixth offense, or even a seventh OWI charge, our firm is prepared to fight for you at every stage of the process.
Do not wait to get help. The sooner you speak with an attorney, the more options you are likely to have. Contact Nero DUI Defense today at (715) 318-7000 to schedule your free consultation. We are ready to listen, answer your questions, and help you understand what comes next.
