DWI Field Sobriety Tests in Texas

About the Standardized Roadside Sobriety Tests

In the past, the decision of whether or not to arrest a suspect for driving while intoxicated (DWI) was largely up to the discretion of the law enforcement officer. As a result, many people were wrongfully arrested, since the officer's own subjective opinion was the yardstick used to determine whether or not the suspect was alcohol impaired.

At the same time, many drivers who were guilty of driving under the influence of alcohol escaped detection and were permitted to continue down the road. In an effort to improve the accuracy of law enforcement efforts in drunk driving investigations, the National Highway Traffic Safety Administration (NHTSA) commissioned research beginning in 1975 for the development of a standardized battery of field sobriety tests.

Field Sobriety Tests Are Not Perfect

Beginning in 1981, law enforcement agencies throughout the nation began using the NHTSA's three field sobriety tests, which include the One-Leg Stand, the Walk-and-Turn and the Horizontal Gaze Nystagmus. These tests, however, are not perfect. According to the NHTSA's own statistics, each one of the tests is less than fully accurate. The Horizontal Gaze Nystagmus is successful in determining whether a driver is legally intoxicated in only 88 percent of cases.

The One-Leg Stand is only 83 percent accurate, and the Walk-and-Turn is only 79 percent accurate. The accuracy of the combined battery of tests is reported to be 91 percent, meaning that there is a one-in-ten chance that a person who fails the tests has not actually broken the law.

Did the Officer Make Mistakes Conducting the Field Sobriety Tests?

Beyond the fact that even the NHTSA admits that its field sobriety tests are less than perfect, there is also the issue of the competence of the law enforcement officer. Administration of the field sobriety tests requires extensive training, and not all officers are fully qualified.

By aggressively cross-examining the officer in the courtroom, your Dallas DWI attorney may be able to reveal that he or she does not fully understand the procedures and is not capable of delivering tests which can be considered to be reliable as evidence in a court of law.

Further, it may be possible to subpoena the footage from the squad car's dashboard video camera with the goal of securing evidence that you did not actually fail the test, or that other circumstances such as poor roadside conditions made it difficult or impossible for you to pass.

Find out more about the strategies that can used to invalidate the field sobriety tests and get started on a plan of action for defending your rights by contacting us at the Mathur Law Offices, P.C., for an initial case evaluation.