What First-Time DWI Defendants Need to Know About Field Sobriety Testing in Texas 

 Posted on October 01, 2025 in DWI

If you are stopped on suspicion of driving while intoxicated anywhere in Tarrant County, the officer may ask you to take field sobriety tests. These roadside tests are designed to measure balance, coordination, concentration, and divided attention, but they are not always reliable.

For someone facing a first-time DWI charge, the results of these tests can have a major impact on how a case turns out. Understanding how field sobriety testing works, can help you make informed decisions about your defense. Our Arlington, TX DWI defense attorney is here to help with your case, from start to finish. 

What Are Field Sobriety Tests?

Field sobriety tests are standardized evaluations developed by the National Highway Traffic Safety Administration (NHTSA) to help officers determine whether a driver may be impaired. The three standardized tests are described in detail in the NHTSA Field Sobriety Testing Manual.

Horizontal Gaze Nystagmus (HGN) Test

The officer tells you to follow a small object, such as a pen or flashlight, with your eyes. If your eyes jerk involuntarily at certain angles, the officer may interpret that as a sign of intoxication.

Walk-and-Turn Test

You are asked to take nine heel-to-toe steps in a straight line, turn, and return in the same manner. The officer looks for balance problems, starting too soon, or failure to follow instructions.

One-Leg Stand Test

You must stand on one leg for about 30 seconds while counting aloud. The officer records swaying, hopping, or putting your foot down as signs of possible impairment.

Divided Attention Testing

Each of these exercises is also considered a divided attention test. The NHTSA developed them based on the idea that impaired drivers struggle to do tasks that take mental focus and physical coordination at the same time. Mistakes in divided attention tasks are used by officers to argue that alcohol or drugs impaired driving ability.

Why Field Sobriety Tests Are Unreliable

Even when properly administered, these tests are not perfect indicators of intoxication. NHTSA research suggests accuracy rates of only 65 to 77 percent under ideal conditions.

Problems that can affect results include:

• Medical conditions such as vertigo, inner ear problems, or injuries.

• Environmental factors such as poor lighting, uneven ground, or bad weather.

• Officer bias, since many drivers are already considered suspects before testing begins.

These factors mean a sober person can easily perform poorly on a field sobriety test. A defense lawyer may argue in court that these results are not credible evidence of intoxication.

Can You Refuse Field Sobriety Tests in Texas?

Texas law does not require drivers to take field sobriety tests. You can politely refuse to participate. Refusal is not subject to the same penalties as refusing a breath or blood test under the Texas implied consent law. That said, an officer may still arrest you. Refusing the tests may avoid giving the state additional evidence, but it will not prevent arrest.

Consequences for a First-Time DWI in Texas

Many drivers first encounter field sobriety testing during a first-time DWI stop. A first DWI in Texas carries serious penalties under the Texas Penal Code §49.04. It is a Class B misdemeanor that permanent remains on your record. Maximum penalties include from 72 hours to 180 days in jail and fines up to $2,000. 

If your blood alcohol concentration is 0.15 percent or higher, the charge may be upgraded to a Class A misdemeanor, with fines up to $4,000 and possible jail time up to one year.

The Texas Department of Public Safety may also suspend your driver’s license for 90 days to one year after a first-time DWI. Some drivers may qualify for an Occupational Driver’s License that allows limited driving for work or family responsibilities.

A DWI conviction cannot be expunged from your record. This can affect employment, professional licenses, and auto insurance premiums for years.

How Field Sobriety Test Results Affect First-Time DWI Cases

Prosecutors often use field sobriety test results to strengthen their cases, especially when chemical test results are borderline. However, these tests can be challenged.

Common defense strategies include showing that the officer did not follow NHTSA procedures or that poor road or weather conditions influenced the results. A defense attorney may also be able to give medical evidence explaining balance or coordination issues.

When the credibility of the tests is undermined, prosecutors may be more willing to reduce charges or dismiss the case.

Legal Defenses in First-Time DWI Cases

Defense strategies in DWI cases totally depend on the specifics of a case, but they often include:

• Challenging the legality of the traffic stop.

• Showing field sobriety tests were administered incorrectly.

• Questioning the accuracy of breath or blood alcohol tests.

• Providing alternative explanations for observed behavior.

A Fort Worth DWI defense lawyer at The Dameron Law Firm can review the circumstances of your arrest and determine the strongest defense strategy.

Frequently Asked Questions About First-Time DWI Cases in Texas

Do I have to take a breath test after failing field sobriety tests? 

You can refuse to provide a sample. Under Texas implied consent law, refusal to take a chemical test or providing a sample over .08 can result in a license suspension. A license hearing can be requested within fifteen days to contest the suspension.

Can a first DWI be dismissed in Texas? 

Yes. Cases may be dismissed if evidence is weak, procedures were mishandled, or rights were violated.

How long does a first DWI stay on my record? 

Unless it qualifies for expunction or nondisclosure, a DWI conviction is permanent.

Is jail time mandatory for a first DWI? 

Not always. Many first-time offenders are placed on probation instead of serving jail time.

Contact an Arlington, TX DWI Defense Lawyer

Field sobriety tests, including the divided attention exercises used by officers, are a common part of DWI arrests in Texas. They are not always accurate and you have rights. 

If you or a loved one is facing a DWI charge, contact The Dameron Law Firm for a free consultation. The right defense strategy from our Tarrant County DWI defense attorney can make a significant difference in your case. Call 817-222-0624 for a free consultation.