You’re pulled over on a Nashville road at 11 p.m. The officer smells alcohol, or says he does. He asks you to step out of the vehicle and perform some tests — walk a straight line, stand on one leg, follow a pen with your eyes. You’re nervous, the pavement is uneven, and you’re wondering: do I have to do this?
N. Cate Law defends Nashville DUI charges across Davidson County and Middle Tennessee. Free consultation: (615) 664-8083.
The short answer is no. Field sobriety tests are voluntary in Tennessee. You cannot be arrested for refusing them, you cannot lose your license for refusing them, and there is no statute that compels you to perform them. But the full picture is more complicated than a one-word answer, and understanding the distinction between field sobriety tests and chemical tests could be the most important thing you learn before your next encounter with law enforcement.
I’m Nathan Cate, a Nashville criminal defense attorney who handles DUI cases across Davidson County and Middle Tennessee. Here’s what you need to know.
What Are Field Sobriety Tests?
Field sobriety tests — sometimes called FSTs or SFSTs (Standardized Field Sobriety Tests) — are a battery of physical and cognitive exercises that officers use to assess whether a driver is impaired. They are administered roadside, before any arrest, and the results are used to build probable cause for a DUI arrest.
The National Highway Traffic Safety Administration (NHTSA) has standardized three tests that are used nationwide, including in Tennessee:
Horizontal Gaze Nystagmus (HGN)
The officer holds a pen or small flashlight about 12 inches from your face and asks you to follow it with your eyes. The officer is looking for involuntary jerking of the eye (nystagmus) that becomes more pronounced with alcohol consumption. There are specific clues the officer is trained to observe — onset of nystagmus before 45 degrees, lack of smooth pursuit, and distinct nystagmus at maximum deviation.
The HGN test is considered the most reliable of the three standardized tests, but it has significant limitations. Nystagmus can be caused by medical conditions, medications, fatigue, caffeine, and even contact lenses. The officer’s administration of the test is critical — if the stimulus is held too close, moved too fast, or conducted in an environment with distracting lights (like flashing patrol car lights on the side of a highway), the results are compromised.
Walk-and-Turn
The officer instructs you to walk nine steps heel-to-toe along a straight line, turn in a prescribed manner, and walk nine steps back. The officer looks for eight clues: can’t balance during instructions, starts too soon, stops walking, doesn’t touch heel-to-toe, steps off the line, uses arms for balance, makes an improper turn, and takes the wrong number of steps.
This is a divided-attention test — it requires you to listen to instructions while performing a physical task. The theory is that impaired individuals struggle to do both simultaneously. The problem is that plenty of sober people also struggle with this test. Uneven pavement, poor lighting, uncomfortable shoes, nervousness, age, weight, inner ear conditions, and orthopedic injuries all affect performance. I’ve watched dashcam footage of officers administering this test on sloped gravel shoulders and then testifying that the defendant “couldn’t maintain balance.”
One-Leg Stand
The officer asks you to stand on one foot with the other foot raised approximately six inches off the ground while counting aloud for 30 seconds. The officer watches for four clues: swaying, using arms for balance, hopping, and putting the foot down.
Thirty seconds is a long time to stand on one foot, especially on the side of a road at night while a police officer stares at you and a patrol car’s blue lights are flashing in your peripheral vision. This test is heavily influenced by age, physical condition, and the surface you’re standing on. NHTSA’s own research acknowledges that people over 65, people more than 50 pounds overweight, and people with back, leg, or inner ear problems should not be asked to perform this test.
Field Sobriety Tests Are Voluntary — Here’s Why
Tennessee does not have a statute requiring drivers to submit to field sobriety tests. The distinction is critical and comes down to this: field sobriety tests are pre-arrest investigative tools. They are requests, not demands.
This is where most people get confused, because there is a Tennessee statute — Tenn. Code Ann. § 55-10-406 — that creates consequences for refusing a test. But that statute is the implied consent law, and it applies to chemical tests (breath, blood, or urine) administered after an arrest, not to field sobriety tests administered on the roadside before any arrest.
Let me make the distinction as clear as I can:
| | Field Sobriety Tests | Chemical Tests (Breath/Blood) | |—|—|—| | When administered | Before arrest, roadside | After arrest, at station or hospital | | Statutory basis | None — officer request only | Tenn. Code Ann. § 55-10-406 (implied consent) | | Can you refuse? | Yes, with no legal penalty | Yes, but with license revocation consequences | | Consequence of refusal | None specified by law | 1-year license revocation | | Purpose | Build probable cause for arrest | Obtain BAC evidence for prosecution |
The implied consent statute is clear: by driving on Tennessee roads, you consent to a chemical test when an officer has probable cause to believe you are driving under the influence. But this consent applies to the post-arrest chemical test — not to the pre-arrest roadside exercises.
Why Refusing Is Often the Right Strategic Call
I’m not going to tell you what to do the next time an officer asks you to step out and perform field sobriety tests. That decision is yours in the moment. But I will tell you what I’ve learned from handling hundreds of DUI cases in Nashville: the results of field sobriety tests rarely help you, and they frequently hurt you.
The tests are designed to produce failure indicators
Even NHTSA’s own validation studies show significant error rates. The HGN test is rated at 77% accuracy for identifying BACs above .10. The walk-and-turn is rated at 68%. The one-leg stand is rated at 65%. Those numbers mean that sober people fail these tests at meaningful rates — and those validation numbers come from controlled laboratory settings, not from the side of Interstate 24 at midnight.
The officer has often already decided
In many cases I’ve reviewed, the officer’s decision to arrest was effectively made before the field sobriety tests began. The tests serve to generate documented evidence supporting a decision that was already forming. The officer smelled alcohol, observed bloodshot eyes, heard slurred speech, and asked for the tests to build a stronger probable cause narrative in the arrest report. Your performance on the tests adds to the State’s case — it rarely subtracts from it.
Poor conditions are common
I’ve reviewed dashcam footage where field sobriety tests were administered on gravel shoulders, sloped pavement, wet grass, and poorly lit parking lots. The NHTSA manual specifies that tests should be conducted on a hard, dry, level, non-slippery surface with adequate lighting. That standard is routinely not met, but it takes a defense attorney reviewing the footage to raise the issue.
Nervousness mimics impairment
The physical symptoms of nervousness — trembling, sweating, difficulty concentrating, fumbling — overlap significantly with what officers are trained to interpret as signs of impairment. A sober person who is frightened by a police encounter at night may exhibit clues that score as “failed” on the officer’s field sobriety test sheet.
What the Officer Might Say
Officers are trained to frame the request in a way that implies compliance is required. You may hear:
- “I need you to step out and perform some tests.”
- “I’m going to have you do a few quick exercises.”
- “This will only take a minute and then we can get you on your way.”
None of these is an order backed by legal authority to compel your compliance with field sobriety tests. The officer is making a request. You can politely decline: “I respectfully decline to perform field sobriety tests.”
The officer may tell you that refusing will make things worse. The officer may say that cooperation will help you. In my experience, the arrest decision is made based on the totality of what the officer has already observed — and your field sobriety test performance just adds evidence to a case that’s already being built.
What Happens After You Refuse
If you decline field sobriety tests, the officer still has everything else observed during the stop: the smell of alcohol, your speech pattern, your eyes, your demeanor, how you handled your documents. If those observations are sufficient for probable cause, the officer can and will arrest you for DUI without field sobriety test results.
The arrest triggers the implied consent framework. At that point, you will be asked to submit to a chemical test — breath or blood. This is where Tenn. Code Ann. § 55-10-406 applies, and the consequences of refusal are concrete: a one-year driver’s license revocation, independent of the outcome of the DUI case itself. The chemical test refusal is a separate administrative proceeding.
So here is the practical landscape: you can refuse field sobriety tests with no statutory penalty, and your refusal gives the State less evidence to work with at trial. If the officer arrests you anyway, the implied consent chemical test is a separate decision with separate consequences.
Can the Prosecutor Use Your Refusal Against You?
This is a common concern. If you refuse field sobriety tests, can the prosecutor tell the jury you refused and argue that you refused because you knew you’d fail?
Tennessee courts have addressed this in the context of chemical test refusal. In State v. Sensing, 843 S.W.2d 412 (Tenn. 1992), the Tennessee Supreme Court held that evidence of refusal to submit to a blood alcohol test is admissible. The logic extends to field sobriety test refusal — the prosecutor may attempt to introduce the fact that you declined.
However, the refusal is not an admission of guilt. It is evidence that the jury can weigh, but the defense can explain it: you refused because you knew the tests were unreliable, because you were nervous, because you were exercising your legal right. Jurors understand that people exercise rights for many reasons, and “I didn’t want to perform a balancing test on the side of a highway at midnight” is a reasonable explanation that resonates with jurors who can imagine themselves in the same situation.
In my experience, the evidence the State loses by not having field sobriety test footage (no video of you stumbling, swaying, or losing count) outweighs the marginal impact of the refusal itself being mentioned at trial.
The Bottom Line
Field sobriety tests are voluntary in Tennessee. No statute requires you to perform them. No penalty attaches to declining. The implied consent law — Tenn. Code Ann. § 55-10-406 — applies to chemical tests after arrest, not to roadside exercises before arrest.
Whether you choose to perform or decline is a judgment call that depends on your circumstances in the moment. But the law gives you the right to say no, and in many cases, exercising that right means the State goes to trial with less evidence against you.
If you’ve been arrested for DUI in Nashville or anywhere in Middle Tennessee — whether you performed the field sobriety tests or refused them — the case is defensible. The question is how to defend it, and that depends on the specific facts. You can read more about how I approach DUI defense on my DUI practice page.
Frequently Asked Questions
Is refusing a field sobriety test the same as refusing a breathalyzer?
No. These are two entirely different refusals with different legal consequences. Field sobriety tests (walk-and-turn, one-leg stand, HGN) are voluntary pre-arrest exercises with no statutory penalty for refusal. A breathalyzer or blood test after arrest falls under Tennessee’s implied consent law, Tenn. Code Ann. § 55-10-406, and refusal triggers a one-year license revocation. The two should never be confused.
Will the officer arrest me if I refuse field sobriety tests?
The officer may arrest you if the other evidence — smell of alcohol, driving pattern, your speech and demeanor — provides probable cause for a DUI arrest. Refusing field sobriety tests does not prevent an arrest, but it does prevent the State from having video evidence of you failing roadside tests. The arrest decision is based on the totality of the circumstances, not solely on field sobriety test results.
Can I refuse the HGN (eye) test but agree to the walk-and-turn?
Legally, you can consent to some tests and decline others. Each test is a separate request. However, in practice, partially cooperating can create a mixed record that is harder to work with at trial. Most defense attorneys advise that if you’re going to decline, decline all three standardized tests rather than selectively participating.
Are field sobriety tests accurate?
According to NHTSA’s own validation studies, the three standardized tests have accuracy rates well below 100%. The HGN is rated at approximately 77% accurate, the walk-and-turn at 68%, and the one-leg stand at 65%. These numbers come from controlled research conditions — accuracy on the side of a dark road with flashing lights, uneven pavement, and a nervous subject is likely lower. Medical conditions, medications, age, weight, and environmental factors all affect performance.
What if the officer says I have to do the field sobriety tests?
Officers may frame the request in a way that implies it’s mandatory. Phrases like “I need you to step out and perform some tests” sound like commands, but they are requests. There is no Tennessee statute requiring you to perform roadside field sobriety exercises. You can politely but clearly decline: “I respectfully decline to perform field sobriety tests.” If the officer insists, your refusal is documented and becomes part of the record — but the law does not punish you for it.
Should I tell the officer I’ve been drinking?
No. You have the right to remain silent. You must provide your license and registration, but you are not required to answer questions about whether you’ve been drinking, where you’re coming from, or how much you’ve consumed. Anything you say during a traffic stop can and will be used against you. “I’d prefer not to answer questions” is a complete and legal response.
Charged with DUI in Tennessee? Call (615) 664-8083 for a free consultation.