Being asked to step out of your car on the side of the road can make even the calmest person nervous. Within minutes, an officer may ask you to follow a pen with your eyes, walk a straight line, or balance on one foot. If the officer decides you did not pass, you may soon find yourself under arrest for driving while intoxicated.

A poor showing on these roadside tests does not mean a DWI conviction is certain. Talking with a Fort Worth field sobriety test lawyer can help you learn whether the tests were given correctly and how the results may be challenged. Below, we explain how field sobriety tests work, why sober people sometimes fail them, and what happens after an arrest in Texas.

The Three Standardized Field Sobriety Tests

The National Highway Traffic Safety Administration (NHTSA) has approved three standardized field sobriety tests that police across the country are trained to use. Each test has specific instructions the officer is supposed to give and specific clues the officer is supposed to look for.

Horizontal gaze nystagmus (HGN). The officer moves a pen or small light from side to side and watches your eyes for involuntary jerking. Alcohol can make this jerking happen sooner or more clearly, but so can certain medical conditions.

Walk-and-turn. You are asked to take nine heel-to-toe steps along a line, turn in a set way, and take nine steps back. The officer watches for things like stepping off the line, using your arms for balance, or starting too soon.

One-leg stand. You raise one foot about six inches off the ground and count out loud for roughly 30 seconds. Swaying, hopping, or putting your foot down can all be counted against you.

Are Field Sobriety Tests Required in Texas?

Many drivers do not realize that roadside sobriety tests are voluntary in Texas. The state’s implied consent law applies to breath and blood tests after an arrest, and refusing those can lead to an automatic license suspension. Field sobriety tests are different, and declining them does not trigger that same penalty.

That said, refusing is not free of risk. An officer may still arrest you based on other observations, such as the smell of alcohol, slurred speech, or the way you were driving. Texas courts have also allowed prosecutors to mention a refusal at trial, so the decision is not as simple as it may sound.

Why Sober Drivers Sometimes Fail

Field sobriety tests measure balance, coordination, and the ability to follow directions, and many things besides alcohol can affect those skills. Inner ear problems, back or knee injuries, being overweight, and older age can all make the walk-and-turn and one-leg stand harder. Some eye conditions and medications can also cause the eye movement that officers look for during the HGN test.

The setting matters too. A sloped shoulder, loose gravel, strong wind, flashing police lights, and passing traffic can throw anyone off balance. Shoes like heels or boots, cold weather, and simple nerves from being pulled over at night can make a sober person look impaired on camera.

Officer Mistakes and the Role of Video

NHTSA’s own training materials stress that these tests are only reliable when they are given exactly the way officers are trained. If an officer gives unclear instructions, holds the pen at the wrong distance during the HGN test, or runs the tests on an uneven surface, the results may carry far less weight. A defense lawyer will often compare what the officer wrote in the report with what actually happened.

That is where body camera and dash camera footage becomes so important. Video can show the road conditions, the lighting, how the instructions were given, and how you really performed. Sometimes the footage tells a very different story than the arrest report, which can lead to evidence being challenged or a case being reduced or dismissed.

What Happens After a DWI Arrest

A DWI arrest in Texas usually starts two separate cases. The first is the criminal case in court. The second is a civil license case run by the Texas Department of Public Safety, which can suspend your license if you fail or refuse a breath or blood test.

The license case moves fast. Under the Texas DPS Administrative License Revocation program, you have only 15 days from the date you receive notice to request a hearing, or the suspension typically takes effect on the 40th day. On the criminal side, a first DWI is usually a Class B misdemeanor with 72 hours to 180 days in jail and a fine of up to $3,000. A blood or breath alcohol level of 0.15 or higher raises it to a Class A misdemeanor, with up to a year in jail and a fine of up to $4,000.

DWI Stops in Fort Worth

Fort Worth has a lively restaurant and bar scene, and DWI enforcement tends to be heaviest near popular spots like Magnolia Avenue on the Near Southside, the West 7th district, Sundance Square, and the Stockyards. Many stops also happen on major roads such as Interstate 35W, Interstate 30, Loop 820, and the Chisholm Trail Parkway, especially late at night and on weekends. Fort Worth police, the Tarrant County Sheriff’s Office, and state troopers all patrol for impaired drivers, and holiday weekends often bring extra patrols.

Most first-time DWI cases in Fort Worth are heard in the Tarrant County Criminal Courts at Law, while felony DWI cases move to the district courts. Because roadside stops in the area are often recorded, getting a copy of the video early can be one of the most useful steps in building a defense.

A Failed Test Is Not the End of the Story

Field sobriety tests are designed to help officers make quick decisions at the roadside, but they are far from perfect. Medical issues, poor test conditions, and officer mistakes can all make a sober driver look impaired. If you were arrested after a failed test, keep track of the 15-day deadline for your license hearing, write down what you remember about the stop, and get legal advice early so you understand every option available to you.