What Are Field Sobriety Tests?

Beginning in 1975, the National Highway Traffic Safety Administration (NHTSA) sponsored research that led to the development of standardized methods for police officers to use when evaluating motorists who are suspected of Driving/Operating While Impaired (DWI/OWI). In 1981, law enforcement officers from across the United States began using NHTSA’s Standardized Field Sobriety Test (SFST) battery to help make arrest decisions at and above the 0.10 percent blood alcohol concentration (BAC). Since the initial implementation, states lowered their BAC limits to .08, thus raising the question of how well the SFST can identity motorists suspected of driving with BACs less than 0.10 percent.

If a law enforcement officer stops a vehicle and suspects that the driver may be intoxicated, the officer may conduct a series of tests on the driver to assist the officer in determining whether the driver is impaired by alcohol. The police officers claim that the tests are standardized and serve as a good indicator of whether the driver’s alcohol level is above .10.

As a practical matter, field sobriety tests usually involve a police officer asking a driver to perform three distinct tests. The first test administered is referred to as the horizontal gaze nystagmus test. During this test, the officer introduces a stimulus (typically a pen or finger) and moves the stimulus in a certain pattern in front of the driver eyes. The officer is trained to look at the driver’s eyes and watch for nystagmus. Nystagmus is a medical condition that can cause the eyes to “jerk” when moving from left to right. Nystagmus can be caused by a number of factors, including alcohol so it is important to retain an attorney familiar with pseudo-science underlying this test.

The remaining two standardized tests are walk and turn and the one legged stand. In the walk and turn test, the driver is instructed to take nine steps, touching heel to toe on each step, along an imaginary straight line. After the completion of the nine steps, the driver is instructed to perform an awkward turning movement and return to the starting point. During the test the officer observes the driver and is trained to note whether the person can remaining in the starting position, takes the correct number of steps, and touches heel to toe when walking among other “clues of impairment.”

The one legged stand test is the most straightforward and requires a driver to stand on one leg and balance for approximately 30 seconds. The officer is trained to watch for swaying and loss of balance.

It should be noted that a motorist does not have a right to consult with an attorney before deciding whether to complete the field sobriety tests. In addition, although there is no legal penalty for refusing to complete the field sobriety tests as requested; however, in our experience a refusal to complete the field sobriety tests will typically result in the officer detaining the driver for chemical testing of the driver’s breath, blood or urine. Finally, police officers frequently record field sobriety tests with the cameras mounted on the squad cars so remember that your words or actions will be captured on video for use later in court. The same videos can also be used to demonstrate that the officer did not perform the tests correctly or otherwise present avenues to impeach the investigating officer’s use of this tool.

At LawtonCates, we believe these standardized tests are subjective in nature and do not necessarily serve as a reliable indicator of alcohol induced impairment. Our attorneys are experienced in challenging a police officer’s field sobriety observations in court, which helps ensure our clients receive the justice that they deserve. If you have any questions or concerns about field sobriety tests, please contact our attorneys so we can discuss your case in private.