A field sobriety test identifies signs of impairment, but failing a drunk test doesn’t automatically mean you’ll be convicted of a DUI.
Getting pulled over by a police officer can be nerve-wracking, especially if you’re asked to perform a field sobriety test. These tests, sometimes referred to as a drunk test, are designed to help officers determine whether a driver is impaired. But many people don’t fully understand what a sobriety test entails or how reliable they are in leading to a DUI arrest. By learning about DUI field sobriety tests and your legal rights, you can navigate this potential situation with confidence and clarity.
This blog is for informational purposes and is not legal advice, consult an experienced DUI attorney if you need additional support.
What Are Field Sobriety Tests?
Field sobriety tests are physical and cognitive exercises administered by law enforcement during traffic stops to assess whether you’re driving under the influence of alcohol or drugs. These tests are part of the Standardized Field Sobriety Testing (SFST) system developed by the National Highway Traffic Safety Administration (NHTSA). While field sobriety tests are widely used, they are not foolproof and rely heavily on the officer’s observations.
These tests identify subjective signs of impairment, such as poor balance, lack of coordination, or difficulty following instructions. However, factors like medical conditions, anxiety, or even uneven road surfaces can influence your performance, even if you’re sober.
The Three Standardized Field Sobriety Tests
Law enforcement officers typically administer three standardized field sobriety tests during DUI stops. These tests are recognized by the NHTSA and are designed to evaluate physical and cognitive abilities that may be impaired by alcohol or drugs.
Horizontal Gaze Nystagmus (HGN) Test
In this test, the officer asks you to follow an object, such as a pen or flashlight, with your eyes while keeping your head still. The officer looks for involuntary jerking movements in your eyes (nystagmus), which can indicate impairment. While this test is considered one of the most reliable field sobriety tests, certain medical conditions or medications can cause nystagmus even in sober individuals.
Walk-and-Turn Test
This test evaluates balance, coordination, and following instructions. You’re asked to take nine heel-to-toe steps in a straight line, turn around, and take nine steps back while counting aloud. The officer watches for signs of impairment, such as losing balance or stepping off the line. Factors like uneven surfaces or nervousness can affect performance.
One-Leg Stand Test
In this test, you’re instructed to stand on one leg while raising the other foot about six inches off the ground. You must hold this position while counting aloud for 30 seconds. The officer looks for swaying, hopping, or putting your foot down. These movements are considered potential indicators of impairment. However, physical limitations or fatigue can impact results.
Are Field Sobriety Tests Accurate?
Field sobriety tests are widely used by law enforcement, but their accuracy is debated. According to studies conducted by the NHTSA, these standardized tests have an accuracy rate of approximately 77% for detecting drivers with a blood alcohol concentration (BAC) of 0.08% or higher when all three tests are administered together. However, individual test accuracy varies:
- Horizontal Gaze Nystagmus: ~88% accurate
- Walk-and-Turn: ~79% accurate
- One-Leg Stand: ~83% accurate
While these numbers may seem reliable, external factors, such as medical conditions, poor lighting, or uneven terrain, can skew results. Field sobriety tests are frequently challenged in court due to their subjective nature and the potential for human error.
What Happens If You Fail a Field Sobriety Test?
Failing a field sobriety test doesn’t automatically mean you’ll be convicted of DUI. It gives officers probable cause to conduct further testing or make an arrest. If you fail one or more field sobriety tests:
- Officers may administer a breathalyzer test to confirm impairment.
- You could be arrested if additional evidence supports DUI suspicion.
Your performance on these tests may be used as evidence against you in court
Can You Refuse a Field Sobriety Test?
Yes, you can refuse to take a field sobriety test in most states, but refusal comes with consequences. Field sobriety tests are voluntary in many jurisdictions; however, declining them may raise suspicion. Refusing a field sobriety test is not the same as refusing a chemical test (like a breathalyzer or blood test). Chemical test refusal often leads to automatic penalties under implied consent laws, including license suspension and fines.
Refusing a drunk test does not prevent an officer from arresting you if they believe there is sufficient probable cause based on other observations, such as your driving behavior, speech, or physical appearance. In court, prosecutors might use your refusal as evidence to argue you were aware of your intoxication, which could complicate your defense.
If you choose to refuse a field sobriety test, remain calm and politely state your decision while complying with other lawful requests from the officer. Understanding the laws in your state and consulting with a DUI attorney after any refusal can help you navigate the legal implications effectively.
Field Sobriety Tests vs. Breathalyzer: What’s the Difference?
Field sobriety tests assess physical coordination and cognitive abilities through observation-based exercises. In contrast, breathalyzer tests provide objective measurements of BAC levels using scientific equipment.
Breathalyzer results are generally more reliable than field sobriety tests because they eliminate subjective interpretation by officers. However, breathalyzers aren’t immune to errors; improper calibration or user error can affect results.
This distinction underscores why breathalyzer tests play such an important role in DUI investigations; they provide objective evidence that complements (or challenges) observations from field sobriety tests.
How to Challenge a Failed Field Sobriety Test in Court
If you believe you were wrongly arrested based on failed field sobriety tests, you can challenge their validity in court by presenting evidence such as:
- Medical records showing conditions that affected performance.
- Witness testimony about environmental factors during testing.
- Expert analysis questioning the reliability of field sobriety test administration.
Hiring an experienced DUI attorney increases your chances of successfully contesting flawed evidence.
FAQs About Field Sobriety Tests
What are the three standardized field sobriety tests?
The Horizontal Gaze Nystagmus (HGN), Walk-and-Turn Test, and One-Leg Stand Test.
How accurate are field sobriety tests?
Combined accuracy rates reach about 77%, but individual test reliability varies due to external factors.
Can you refuse to take a field sobriety test?
Yes; however, refusal may raise suspicion.
What happens if you fail a field sobriety test?
Failure provides probable cause for further testing or arrest but doesn’t guarantee DUI conviction.
Is a breathalyzer more accurate than a field sobriety test?
Yes; breathalyzers provide objective BAC measurements compared to subjective observations from officers.
What should I do if I was wrongly arrested after failing a test?
Consult an experienced DUI attorney who can challenge flawed evidence based on medical conditions or procedural errors.
Navigate Field Sobriety Tests with DUI.org
If you are facing a DUI charge based on a field sobriety test result, visit DUI.org for expert resources on understanding your rights and effectively navigating the DUI process. DUI.org does not provide legal advice, so be sure to consult an experienced DUI attorney regarding your situation. DUI.org provides comprehensive information on the DUI experience as well as assistance finding ignition interlock devices and SR-22 insurance.
Get support.
What is next? We can help you through the process. Give us a little information and we can support you through the next steps.
All fields are required.