Field Sobriety Tests: What Texas Drivers Should Expect – Guest Post

Driving in Texas comes with responsibilities, and one of the most stressful experiences a driver can face is being stopped for suspicion of driving while intoxicated (DWI). In these situations, law enforcement officers often rely on field sobriety tests (FSTs) to determine whether a driver may be impaired. Understanding how these tests work, their limitations, and what to expect can help Texas drivers feel more prepared if they ever encounter this situation.

What Are Field Sobriety Tests?

Field sobriety tests are a series of physical and cognitive exercises administered by police officers during a DWI stop. Their purpose is to assess a driver’s balance, coordination, and ability to follow instructions—factors that may indicate impairment.

In Texas, officers typically use a standardized set of tests developed by the National Highway Traffic Safety Administration (NHTSA). These tests are meant to give law enforcement probable cause to make an arrest or request a chemical test, such as a breath or blood test.

The Three Standardized Field Sobriety Tests

1. Horizontal Gaze Nystagmus (HGN)

This test checks for involuntary jerking of the eyes, known as nystagmus, which can become more pronounced under the influence of alcohol. The officer will ask the driver to follow a moving object—such as a pen or flashlight—with their eyes. They look for specific signs, including an inability to smoothly track the object or jerking at certain angles.

2. Walk-and-Turn (WAT)

In this test, the driver must walk heel-to-toe along a straight line, turn carefully, and walk back in the same manner. The officer looks for signs such as losing balance, stepping off the line, or failing to follow instructions. This test challenges both balance and memory, making it more difficult for someone who is impaired.

3. One-Leg Stand (OLS)

The driver is instructed to stand on one leg while counting out loud for about 30 seconds. Officers observe whether the driver sways, hops, or puts their foot down too early. Difficulty maintaining balance during this task can be used as evidence of impairment.

How Accurate Are These Tests?

While field sobriety tests are widely used, they are not foolproof. Factors unrelated to alcohol—such as fatigue, medical conditions, nervousness, or even uneven road surfaces—can affect performance. Studies show that when administered correctly, the three standardized tests combined can predict impairment with a high degree of accuracy, but they are still subject to human error.

Because of these limitations, test results can sometimes be challenged in court. That’s why drivers who face DWI charges should seek legal guidance to review whether the tests were administered properly.

Non-Standardized Tests

In addition to the three standardized tests, some officers may use other exercises such as reciting the alphabet, touching a finger to the nose, or counting backward. These non-standardized tests are not scientifically validated and may carry less weight in court, but they can still influence an officer’s decision during a stop.

What Texas Drivers Should Know About Their Rights

It’s important to understand that field sobriety tests are not mandatory in Texas. A driver can refuse to participate. However, refusal may increase suspicion and lead to an arrest based on other observations, such as driving behavior, speech, or smell of alcohol.

If an arrest is made, Texas’ implied consent law requires drivers to submit to a chemical test (breath or blood). Refusal of a chemical test can result in an automatic license suspension, even if the driver is never convicted of DWI.

What to Do If You Are Arrested

Being arrested after a field sobriety test can be overwhelming, but drivers should remember a few key points:

• Remain calm and respectful during the interaction.
  
• Avoid volunteering additional information beyond what is required.
  
• Contact an experienced defense lawyer as soon as possible.
  

The outcome of a DWI case often depends on the circumstances of the arrest, the reliability of the evidence, and the quality of legal representation.

Why Legal Representation Matters

Field sobriety tests are only one part of the prosecution’s case in a Texas DWI. A skilled attorney can challenge whether the tests were properly conducted, point out inconsistencies in the officer’s report, or highlight other factors that could explain poor performance.

If you or someone you know is facing charges, working with a knowledgeable DWI attorney in San Antonio can make a significant difference in protecting your rights and your future.

Final Thoughts

Field sobriety tests can feel intimidating, but knowing what to expect can help drivers stay informed and prepared. While these tests are used to detect impairment, they are not flawless and may be influenced by many outside factors. For Texas drivers accused of DWI, professional legal representation is the best way to navigate the challenges ahead.