Failing a field sobriety test on the side of a Wisconsin road does not automatically mean you were impaired. Field sobriety tests are deeply subjective tools, and the circumstances surrounding them can produce misleading results for reasons that have nothing to do with alcohol or drugs.
If you or someone you care about is facing OWI charges, let the experienced drunk driving defense lawyers at the Madison law firm of Casper Mehlos Law Grous help you. Wisconsin law treats OWI charges seriously, and so do we. If proper protocols were not followed, the results should be challenged.
What Do Roadside Tests Measure?
Three standardized tests make up what law enforcement uses during most OWI stops in Wisconsin. The National Highway Traffic Safety Administration has endorsed the Horizontal Gaze Nystagmus test, the Walk-and-Turn test, and the One-Leg Stand test as the primary roadside evaluation tools. Officers may also ask drivers to perform non-standardized tasks like reciting portions of the alphabet or counting backward, though those carry far less evidentiary weight.
Wisconsin courts recognize that field sobriety tests are observational tools, not scientific measurements. The perception of performance is necessarily subjective, and the law enforcement officer’s interpretation of what they saw goes to the weight of the evidence rather than some objective standard. That subjectivity opens real doors for a defense.
Wisconsin Weather and Road Conditions
Anyone who has spent a blustery night on the Beltline or pulled off onto the shoulder of I-90 near the Wisconsin Dells knows what Wisconsin weather looks like up close. Standardized field sobriety tests are designed to be performed in good weather and on level, dry, hard, non-slippery surfaces. That is not always what drivers encounter during a roadside stop in Wisconsin.
Uneven pavement, puddles, ice-covered ground (in winter), gravel shoulders, and the blinding glare of passing headlights can all affect a person’s performance regardless of sobriety. A driver pulled over on a poorly lit stretch of Highway 51 during a rainstorm is already working against conditions the tests were never designed for. These environmental factors can absolutely contribute to a failed result, and they are legitimate grounds to challenge what the officer recorded.
Physical Health and Medical Conditions
NHTSA research has recognized that individuals over 65 years of age and those with back, leg, or inner ear problems may have genuine difficulty performing the Walk-and-Turn and One-Leg Stand tests. The research is built into the training. That means an officer who ignores those factors during scoring may have administered the test improperly.
Medical conditions can also affect the Horizontal Gaze Nystagmus test, which looks for involuntary jerking of the eye as it tracks a moving object. Nystagmus can be caused by a range of conditions that have nothing to do with alcohol, including inner ear disorders, certain medications, neurological conditions, and even the presence of rotating lights or rapidly moving objects in a person’s field of vision during the test. A person dealing with an undiagnosed inner ear issue could show signs of nystagmus without having consumed a single drink.
More precisely, some neurological conditions and certain prescription medications can cause a person to appear impaired without any alcohol involvement at all. People with physical or mental disabilities are often wrongfully arrested for OWI. We fight against that on behalf of our clients.
Footwear, Clothing, and Physical Abilities
Officers are actually trained to offer suspects the opportunity to remove shoes or boots with heels higher than two inches before performing balance tests, because footwear will affect a person’s ability to stand and walk properly. If that opportunity was not offered, that is a procedural issue worth arguing about.
Beyond shoes, what the tests often measure is physical agility rather than impairment. Many people who are completely sober struggle to stand on one leg for an extended period or walk heel-to-toe in a perfectly straight line under normal circumstances, let alone on the side of a road with an officer watching and traffic passing at highway speed. Baggy clothing, prior injuries, and general physical fitness all play a role in how someone performs.
Nerves and Anxiety
Being pulled over is stressful. Full stop. For many drivers, the presence of flashing lights, a uniformed officer, and the awareness that every move is being evaluated creates genuine anxiety that affects physical performance. Trembling hands, difficulty following multi-step instructions, and balance issues can all be products of stress rather than impairment.
The tests require a person to divide their attention between physical tasks and verbal instructions simultaneously. Under normal conditions, that is manageable. Under the psychological pressure of a roadside OWI investigation, even a composed, sober person can stumble. Officers are not always in a position to distinguish between nervousness and intoxication, and that gap matters in court.
Officer Error and Improper Administration
Wisconsin law requires that field sobriety tests be administered according to specific protocols. Officials who are trained and certified to administer these tests sometimes make errors in how they conduct and score them. An officer who fails to observe the full test, misinterprets a driver’s movements, or administers instructions incorrectly may produce a flawed result that does not accurately reflect the driver’s true condition.
There is also the question of officer demeanor. If a law enforcement officer takes an aggressive or intimidating tone during the test, that can cause a driver to fail tasks they would otherwise handle without difficulty.
We Help People Fight Wrong Results from OWI Arrests
A failed field sobriety test can feel like the end of the road, but from a legal standpoint, it is often the beginning of a conversation about how the test was conducted, under what conditions, and whether the officer’s interpretation was accurate.
We work with clients throughout Madison, Dane County, and surrounding areas who are facing OWI charges where field sobriety test results are part of the evidence. Every case is different, and the specific facts of what happened on that roadside matters.
If you were charged with OWI in Wisconsin and a field sobriety test was part of how that charge came together, we encourage you to contact Casper Mehlos Law Group for a consultation. Understanding what may have gone wrong during your test is a good place to start.
