When Are Field Sobriety Tests Used in DWI Traffic Stops?

 Posted on January 28, 2022 in DWI

There are many different situations where drivers may be pulled over by police officers because they are suspected of driving while intoxicated (DWI). An officer may believe that a person was driving erratically or exhibiting other signs of intoxication, or they may pull a person over for committing a traffic violation, and their observations of the driver may lead them to suspect that the person is under the influence of alcohol or drugs. However, before an officer can arrest someone for DWI, they must have probable cause or reasonable suspicion that the person is intoxicated. To establish probable cause, an officer may ask a driver to submit to different types of field sobriety tests, and based on their observations during these tests, they may determine that the driver is intoxicated and perform an arrest.

What Officers Look for in Different Types of Field Sobriety Tests

Field sobriety tests are meant to determine whether a person is unable to operate a motor vehicle safely because they are under the influence of intoxicating substances. There are three types of tests that are considered to be “standardized” field sobriety tests that have been validated by the National Highway Traffic Safety Administration (NHTSA).

Two of the three standardized field sobriety tests are known as “divided attention” tests, and they may be used to determine whether a person is able to pay attention to multiple tasks at once, which is a necessary skill for driving. The “walk and turn” test will require a person to take a certain number of heel-to-toe steps in a straight line, turn around, and take the same number of steps to return to their original position. The “one-leg stand” test will require a person to stand with one foot raised off the ground for 30 seconds.

While divided attention tests may indicate intoxication, there are many reasons why a person may fail these tests even if they are not under the influence of alcohol or drugs. A person may suffer from injuries, illnesses, or disabilities that affect their balance. Irregularities in the road or other environmental factors may make it difficult for a person to follow an officer’s instructions. A driver may also fail a test due to the nervousness, anxiety, and stress they experience in this frightening situation.

The third type of standardized field sobriety test, the horizontal gaze nystagmus test, may be used to observe involuntary physical reactions that a person may experience when they are intoxicated. An officer will ask a person to follow the motion of an object with their eyes, and if the person’s eyes jerk involuntarily, this may indicate intoxication. However, there are other reasons why a person may react in this way, such as certain types of medical conditions.

Contact Our Plano DWI Lawyers for Field Sobriety Tests

It is important for drivers to understand that they can decline to take field sobriety tests after being pulled over. The results of field sobriety tests may be challenged in some cases by showing that factors other than intoxication contributed to the failure of one or more tests. At Law Offices of Biederman & Burleson P.L.L.C., we can help you determine the best defense strategy against DWI charges, and we will fight to protect your rights and help you resolve your case successfully. Contact our McKinney DWI defense attorneys by calling 469-333-3333 to arrange a free consultation.

Sources:

https://www.nhtsa.gov/sites/nhtsa.gov/files/documents/sfst_full_instructor_manual_2018.pdf

https://www.tdcaa.com/resources/dwi/field-sobriety-test-review/

https://statutes.capitol.texas.gov/Docs/PE/htm/PE.49.htm