What are Field Sobriety Tests?

If a police officer suspects that you have been drinking or under the influence of a drug based upon the way you are operating your vehicle, the officer may pull your vehicle over and administer one or more field sobriety tests to you. These tests, which are sometimes simply referred to as roadside sobriety tests, are administered in order to enforce the Texas DWI laws. In most instances, officers administer a field sobriety test prior to ever administering a breathalyzer test.

The majority of field sobriety tests that officers administer following a traffic stop consist of three parts. An officer can administer these sobriety tests if he or she has a reasonable suspicion that you are under the influence of alcohol and/or that your driving abilities are impaired. The primary purpose of a field sobriety test is to pay attention to your physical abilities, balance, and ability to pay attention, in order to decide if you are under the influence of alcohol or an illegal substance. These tests are often referred to as divided attention tasks.

It is important to keep in mind that field sobriety tests are not perfect, and there are certain instances where external factors – such as a person’s health condition – may negatively impact the result of a field sobriety test. If you have been charged with driving under the influence, the knowledgeable Frisco DUI/DWI defense lawyers at Brent D. Bowen, Attorney At Law are ready to help. We can examine your circumstances and determine if there is a way to challenge the results of your field sobriety test.

Types of Field Sobriety Tests that a Police Officer May Administer

There are three standard types of field sobriety tests that a police officer may administer during a traffic stop. The main purpose of these tests is for the officer to determine if he or she has probable cause to make an arrest. The National Highway Traffic and Safety Administration (NHTSA) endorses the walk-and-turn (WAT) test, one-leg stand (OLS) test, and horizontal gaze nystagmus (HGN) test.

WAT Test

Police officers use the WAT test to measure a driver’s ability to divide his or her attention between different activities. As part of the test, the driver must take a total of nine heel-toe steps in a straight line. He or she must then turn using a sires of small steps, turning around the front foot and repeat the nine same steps in the other direction.

OLS Test

As part of the OLS test, the driver must stand while one foot is approximately six inches from the pavement. He or she must then count from one to 30, the test is supposed to last 30 seconds. If the driver has to use his or her arms for balance, hops, or has to put the foot down or sways excessively, this may indicate that he or she is impaired by alcohol or drugs.

HGN Test

For the HGN test, the police officer looks to the driver’s eyes in order to establish impairment. Specifically, the officer will look for an involuntary jerking of the eye at various degrees and will test whether the driver is able to smoothly and continuously follow a moving object with his or her eye.

The officer will then consider the results of all three of these tests – as a whole – to gauge whether or not the driver is likely impaired due to alcohol or drugs.

Call a Frisco DWI Defense Lawyer about Your Charges Today

The legal team at Brent D. Bowen, Attorney At Law can assist you with defending against a pending DWI charge. For a free legal consultation and case evaluation with a Frisco DWI defense attorney, please contact us online today.