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Driving While Intoxicated Offenses in Texas

What are DWI “Field Sobriety Tests”?


Field sobriety tests are a battery of standardized tests that are designed to help an officer judge whether or not a person is too impaired to drive. able to complete tests which, had the person not been drinking, would be simple to perform. There are three main field sobriety tests used by law enforcement. They are the Horizontal Gaze Nystagmus, Walk-and-Turn, and One Leg Stand. These tests were developed to test the sobriety of the driver in question and peace officers are trained on how to administer and interpret the results of these tests.


What is the Horizontal Gaze Nystagmus (HGN) test?

HGN is the involuntary jerking of the eyes when a person moves their gaze from side to side. When someone is under the influence of alcohol, this jerking can become exaggerated. To test HGN, a law enforcement officer may use a pen or flashlight and ask the driver to follow it as the officer moves it from side to side. If they notice the tell-tale signs during this test, the driver could be placed under arrest. There are, however, other reasons why an individual may fail this test, such as the use of certain medications or certain illnesses.

What is the Walk and Turn Test?

The Walk and Turn test is a field sobriety test is a divided attention test, meaning it seeks to determine whether or not the person is able to do two things at the same time - like driving. The test divides the person’s attention between receiving verbal instructions while simultaneously performing seemingly simple physical tasks. In theory, this test can easily be completed by people who are not intoxicated. However, impaired drivers find it very difficult to successfully pass. To administer the test, the officer will ask the driver stand in a ready position while receiving verbal instructions, and then to walk in a straight line heel-to-toe for nine steps, make a series of small steps in a particular direction to turn around, and then take nine heel-to-toe steps back. The officer will watch to see how well they are able to follow instructions as well as whether they are able to keep count. If they fail to maintain the ready position during the test’s instructions, or lose their balance or step off of the line, it could be an indicator that they are intoxicated. During trial, officers usually attempt to discuss this test’s accuracy, i.e. how reliably it predicts impairment, demonstrated by observing a certain number of “clues” observed during the test. Proponents of this test assert it produces accurate test results in 79% of the cases. Even though this is a good percentage, it still leaves plenty of room for error. 

What is the One Leg Stand test?

The One Leg Stand test is another divided attention test. To administer the test, the officer asks the person to stand with one foot about six inches from the ground, focus their gaze on their foot, and keep their balance while counting out loud until they reach thirty seconds. Some indicators that the individual may be inebriated include the failure to stay balanced, having to put their foot down, or the necessity to use their arms to stay balanced. Proponents of this test claim it’s an accurate predictor of impairment in 83% of the cases. Again, this is a good percentage, but there’s still a lot of room for error.

Should I agree to perform the field sobriety tests?

You are not required by Texas law to do so. These tests are meant to challenge your abilities to perform mental and physical tasks at the same time. The standard field sobriety tests consist of an eye test, a heel-to-toe walk and turn test, and standing on one leg. These are not simple exercises and can be difficult to do perfectly on the first try, even under the best conditions. For an individual who struggles with balance or physical tasks due to a medical or physical condition, these tests may be nearly impossible. It is ultimately your decision, but consider whether you’re confident in your performance on these tests because “failing” a test can serve as probable cause for your arrest. Further, absent an unusual situation, all of the tests will be recorded on the officer’s in-car video system. This video will then be carefully scrutinized, and every misstep, stumble, sway and slur will be used in some way against you in court.

Should I take a “preliminary breath test” (PBT) on the side of the road?

Why would you? Regardless of the result, the officer has almost certainly already decided to arrest you, and s/he is merely looking for more evidence to support your arrest. In other words, the officer is not looking for a reason to let you go.

PBTs are unreliable and inaccurate. Even the Scientific Director of the Texas Department of Public Safety thinks this is true because none of these devices have been approved or certified for use in Texas. You should not take one of these tests even if the officer promises you that the results cannot be used against you. A good prosecutor will consider it during plea negotiations, and find a way to present it during your trial.

What does Texas’ “implied consent” law require?

Texas’ “implied consent” law requires drivers suspected of DWI to submit to a blood or breath sample for testing. The law, however, also gives every driver the physical ability to refuse to comply, but the consequences of a refusal is a longer period of license suspension.

Should I take a breath test at the police station?

The breath test at the station or in the truck trailer are totally different devices and are much better than those used at the scene. In a typical DWI trial, a suspect’s breath test results will be admissible, and the State isn’t required to demonstrate that the operator has a working knowledge of the scientific theory behind the intoxilyzer. You should only take the "official test" after knowing a little information about those machines.

What should I know before I decide whether or not to take a breath test?


  • They require that you blow into them two times for each test.

  • They may be used thousands of times between each cleaning.

  • They are not used by hospitals.

  • They assume you are a 150 pound male.

  • They assume you fit their definition of the average human subject.

  • They are computers and sometimes make mistakes.

  • They were designed by scientists to determine identity of substances, not their amount. (I.e. qualitative v quantitative devices)

  • They have have been known to report false high results on normal people.

You should also know that these four things can cause abnormally high results:

  • Atkins Diet - If a person has been a disciplined follower for 90 days or more.

  • Dental Work - If you have dentures, capped teeth, missing teeth, braces, retainers or other types of extensive dental work and have been drinking at all.

  • Chemical Exposure - If you work around volatile chemicals, or have been on the day of your stop, you should know that many substances can cause false high results. All petrochemical products, some household cleaning products, floor strippers and refinishers and oil based paints may affect the reported number. People who work in oil fields, car body shops and as manicurists should be particularly careful with their decision to take a breath test. The substances in these work environments enter the body through the skin and the lungs. They are very harmful if overexposure occurs and will be mislabeled as "alcohol" by the breath test machine.

  • Airbag deployment - Some scientists believe, and some studies have shown, that the substance used in air bags to preserve the bags can be inhaled into the lungs and affect a breath test if still present. These cases are rare, but be advised that if you have been in an accident where an airbag has deployed, the airbag may cause a breath test to report more alcohol than is actually present.

Although it’s is your decision whether or not to take a breath test, you probably should not because you don’t have to prove your innocence to anyone. A license suspension is not automatic provided you request Administrative License Revocation hearing within 15 days of your notice. Your odds of losing your license are fairly equal whether you take a breath test or refuse one.

If you take the test and it reports a number of 0.080 or higher prosecution of your criminal DWI case has become much easier for the government to obtain your conviction.


(1) If you don't take a breath test, the State can and certainly will tell the judge or jury about your refusal during a trial. Some people think a person who refuses is guilty. Most people, though, believe that a person with an alcohol concentration over 0.08 is guilty.

(2) Please be advised that a "refusal" as used for these purposes is defined as the failure to print a breath test result whether you try to give one or not. Also, if you request an attorney to help you decide whether to take a breath test is also considered a "refusal".

What if they never "read me my rights"?

Thanks to television and Hollywood, many people have the mistaken belief that, in every instance, their case must be dismissed if the officer failed to “read them their rights.” The "rights" most people are referring to are commonly known as your "Miranda" rights, and come from a U.S. Supreme Court Decision that said that a suspect must be advised of these rights before being subject to custodial interrogation by the police (Miranda v Arizona). 

Your "Miranda" rights are: your right to remain silent and not answer questions without the advice of an attorney; the fact that anything you say can and will be used against you in Court and at your trial, and your right to a court appointed attorney to advise you if you can’t afford to hire one to advise you during questioning. Texas law also adds the right to "terminate the interview at any time".

Generally, if you are in custody and interrogated, without first being so warned, your statements are not be used against you.

The "DWI" Exception

The Supreme Court, though, has held that you are not in "custody" when stopped for a traffic offense and do not, therefore, have to be told you have these rights. They still apply, but the police are under no duty to tell you and there’s no penalty against them if they don’t inform you. It is, therefore, legally acceptable for the police to ask you if you have been drinking and how many drinks you have had before telling you that you are suspected of DWI. It is also acceptable for you to know that you have these rights and politely refuse to respond to an officer's questions if you feel you are not free to go.

If you were arrested for DWI, you were probably advised of these rights after being handcuffed and transported to jail. However, if you responded to the officer’s questions, then you’ve already made statements and the "law" says that those statements are voluntary and it’s okay to use them to prosecute you for DWI.

Will my license be suspended if I did not take a breath test?

Texas law grants you 15 days to contest the automatic suspension. If you request a hearing within this time limit your license will not be suspended until a judge orders that it be suspended.

If you missed the fifteen day deadline your license will automatically be suspended for 180 days beginning on the fortieth (40th) day after your arrest.

Will my license be suspended if I failed the breath test?

Texas law grants you fifteen (15) days to contest the automatic suspension. If you request a hearing within this time limit your license will not be suspended until a judge orders that it be suspended.

If you missed the fifteen (15) day deadline your license will automatically be suspended on the fortieth (40th) day after your arrest for 90 days.

Will my license be suspended if I took a blood test?

Blood tests results are more time consuming to obtain. Blood tests are done in a controlled environment, such as a special room either at a hospital or at a crime lab. If you took a blood test, you should watch your mail. Within about 60 days, you should receive a letter from the Texas Department of Public Safety informing you of whether you failed the blood test. If you passed, they will not send you a letter.

If you receive a letter informing you that you failed a blood test, you have 15 days to contest the suspension. If you request a hearing within this time, your license will not be suspended until a judge orders it suspended.

Texas DPS will send this letter to the address listed on your drivers license. If you move, change your address as quickly as possible. If this letter is mailed to your last address, Texas laws states that you have "received it," and should know that your license is suspended.

What am I supposed to do if my license is suspended?

If your license has never been suspended before, you can request and obtain an "Occupational Drivers License" (ODL). This is a license granted by a judge that can allow you to drive twelve (12) hours every day for your work, your school and your household duties. These hours do not have to be continuous nor do they have to be the same every day. They cannot exceed 12 hours in any 24 hour period and your Order must specify the counties you need to drive in. 

What is an Occupational Drivers License?

When a person's drivers license has been suspended for reasons other than physical or mental disability, a Texas citizen may request and be granted an "Occupational License." This is typically what people do when their license is suspended for refusing or failing a breath test.

An ODL is restricted by purpose, hours and region. An ODL may be granted for not less than four (4) hours nor more than twelve (12) hours per day. These hours don’t have to be continuous, and they may be different for every day of the week.

In most DWI cases, Occupational Licenses are granted for twelve hours each day for the purpose of work related, school related or household-need related driving. These hours only apply to hours physically driving a car. They are also limited by the counties in which these driving activities are anticipated.

Occupational licenses for persons with multiple DWI offenses may contain more stringent restrictions. In some cases, the Petitioner is required to install and maintain a deep lung ignition interlock device (IID) on any vehicle operated during the period the Occupational License is in effect. In some cases hours may be restricted to less than twelve (12) hours. Some driving times may also not be available depending on the particular facts of each individual case.

What are the "usual" probation conditions for a DWI?

Most of the usual conditions of probation are things you’ve done your entire life. These include: don't commit another crime; avoid bad people; avoid bad places; don't use drugs; keep your job; pay your fines and court costs; support your family; and, don't move or change jobs without letting the Court know.

Most probation pleas also require that you complete a DWI education program, attend a Victim Impact Panel, take a substance abuse evaluation and report in person once a month to a "probation officer". In some cases this condition can be eliminated after completion of a portion of the probated sentence.

What "special conditions" go with DWI?

In Texas, other DWI conditions are:

  1. Complete a state approved "DWI Education Program". This is an advanced "Defensive Driving" course that also provides more education about drinking and driving. It is a four-hour, three-day course and can be taken on the weekend.

  2. Attend a Mothers Against Drunk Driving "Victim Impact Panel".

  3. Submit to a written psychological test to evaluate whether or not you may have a tendency toward drugs or alcohol problems. If indicated, participate in counseling, AA, or other program.

What is an "SR-22"?

The SR-22 is a Texas Department Public Safety form that establishes the existence of insurance coverage for a driver. This form is used in most types of license suspensions and more so in DWI cases.

If a license is suspended for failure or refusal of testing, the SR-22 is required to be filed with a Petition (or request) for an Occupational License. Without this form, a Court may not grant an ODL.




The Slaughter Law Firm, PLLC
505 West 12th Street, Suite 200-B
Austin TX 78701


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512-870-9000 fax


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