Yes, you can refuse a field sobriety test in Missouri. No state statute requires you to walk a line, stand on one leg, or follow a pen with your eyes at the roadside, and refusing carries no automatic license penalty. That does not mean refusal ends the encounter or prevents an arrest, and it should not be confused with refusing the chemical test that comes later.
Why Refusal Is Legal
Field sobriety tests are investigative tools, not legal obligations. Missouri’s implied consent law, the statute that actually requires you to cooperate with testing, applies only to chemical tests of your blood, breath, or urine after an arrest or qualifying stop.1Missouri Revisor of Statutes. Missouri Code 577.041 – Refusal to Submit to Chemical Test There is no parallel statute for the roadside balance and coordination exercises officers use to build probable cause.
The three standardized tests an officer is trained to use come from the National Highway Traffic Safety Administration: the Horizontal Gaze Nystagmus test, the Walk-and-Turn, and the One-Leg Stand.2National Highway Traffic Safety Administration. DWI Detection and Standardized Field Sobriety Test Resources An officer can ask you to perform any of them. You can say no.
Because there is no implied consent statute for these tests, refusing brings no license revocation, no administrative hearing, and no separate charge. You decline, and the stop continues.
What Refusal Does Not Do
Refusing a field sobriety test does not prevent a DWI arrest. Officers can still develop probable cause from everything else at the scene: the smell of alcohol, bloodshot eyes, slurred speech, statements you make about drinking, open containers in the car, or the driving that prompted the stop. If those observations add up, the officer will arrest you whether or not you performed the exercises.
Your refusal can also come up at trial. A prosecutor may argue to a jury that you declined the tests because you knew you would fail, presenting the refusal as circumstantial evidence that you were aware of your own impairment. That argument does not prove intoxication on its own, but it gives the state another piece to work with. Whether the trade-off favors you depends on the facts. A sober driver with a knee injury, an inner ear condition, or another issue that affects balance may be better off refusing tests they would fail for reasons unrelated to alcohol. NHTSA’s own materials acknowledge that the tests are designed for “ideal conditions” that “do not always exist” at the roadside, and factors like uneven pavement, poor lighting, wind, age, weight, and nervousness can all produce clues that look like impairment.3National Highway Traffic Safety Administration. DWI Detection and Standardized Field Sobriety Testing Refresher Instructor Guide
Do Not Confuse This With the Chemical Test
The right to refuse ends when the roadside encounter turns into a post-arrest chemical test. Missouri’s implied consent law treats those tests very differently. By driving on Missouri roads, you are deemed to have already consented to a chemical test of your breath, blood, or urine when an officer has grounds to arrest you for DWI. Refusing that test triggers an immediate one-year license revocation, known as a Chemical Revocation.4Missouri Department of Revenue. FAQs – Refusal to Submit to an Alcohol and/or Drug Test
Before administering the chemical test, the officer must explain why the test is being requested and warn you that refusing can be used against you in court and will result in immediate license revocation. If you ask to speak with an attorney first, you get 20 minutes to make contact. If you still refuse after those 20 minutes, Missouri treats it as a refusal.1Missouri Revisor of Statutes. Missouri Code 577.041 – Refusal to Submit to Chemical Test
After a chemical test refusal, the officer issues a 15-day temporary driving permit and notifies the Department of Revenue. You can petition a circuit court for a hearing to challenge the revocation and request a stay that keeps your license active until the court rules. The court examines three things at that hearing: whether you were lawfully arrested or stopped, whether the officer had reasonable grounds to believe you were driving while intoxicated, and whether you actually refused the test.5Missouri Revisor of Statutes. Missouri Code 577.041 – Refusal to Submit to Chemical Test
So: refusing the roadside exercises is a decision with modest costs. Refusing the chemical test at the station is a decision that costs you your license for a year on its own.
The Preliminary Breath Test Sits in Between
There is one more roadside request drivers often confuse with both categories. Missouri law authorizes officers to administer a portable breath test before making an arrest. This preliminary breath test is not the post-arrest chemical test, and the statute explicitly says the implied consent rules do not apply to it. The numerical result can be used to establish probable cause for an arrest, but it cannot be used in court as evidence of your actual blood alcohol level.6Missouri Revisor of Statutes. Missouri Code 577.021 – Chemical Tests Prior to Arrest
Practically, the preliminary breath test is voluntary in the same sense a field sobriety test is: no automatic license revocation for refusing. If an officer hands you a handheld device at the roadside before arresting you, that is the preliminary breath test. The formal chemical test happens later, usually at the station or a hospital, and the consequences for refusing it are the ones described above.
How to Decline During a Stop
Pull over safely, turn off the engine, keep your hands visible, and stay calm. Provide your license, registration, and proof of insurance when asked. You are legally required to identify yourself. Everything after that becomes a choice.
You are not required to answer questions about where you were, where you are going, or whether you have been drinking. Telling an officer you had “just two beers” gives them evidence that you consumed alcohol, which strengthens probable cause. A polite “I’d prefer not to answer that” is within your rights.
If the officer asks you to perform field sobriety tests, “I respectfully decline” is enough. If the officer asks you to blow into a handheld device at the roadside before any arrest, that is the preliminary breath test, and the same short answer works.
If the officer arrests you and requests a chemical test at the station, the calculus changes. Refusing that test means a one-year license revocation, and the refusal itself becomes admissible evidence.1Missouri Revisor of Statutes. Missouri Code 577.041 – Refusal to Submit to Chemical Test Ask for your 20 minutes to reach a lawyer, and use them.