If an officer in Galveston, Texas, suspects a drunk driver, they may conduct field sobriety tests. These tests are preliminary measures to check a driver for impairment. There are three field tests the National Highway Traffic Safety Administration considers standard.
Standard field sobriety tests
During the walk-and-turn test, the driver takes nine steps in a straight line, heel-to-toe, counting the steps. The driver must keep arms at their sides, turn on one leg, and repeat the other direction. The officer watches for several cues, which include using arms to balance, getting off the line, and following directions.
The one-leg stand test requires the driver to lift one foot 6″ from the ground and balance for 30 seconds. The officer watches for using arms for support, putting a foot down, and swaying, which could indicate drunk driving.
The horizontal gaze nystagmus test checks the vision of the driver by having them follow an object. The test checks for involuntary eye-blinking at 45-degrees, and the jerking becomes more noticeable the more alcohol a person drinks. The officer also looks for smooth pursuit and maximum deviation, or outer eye jerking for four seconds.
Defenses to field sobriety tests
The accuracy of field tests is highly debated, and a driver can use several defenses to challenge results. Medical conditions, such as inner ear infections and musculoskeletal conditions, may make the test hard for some drivers. Age, weight, weather, noises from traffic, and high heels may cause sober drivers to fail the tests.
The NHTSA also has strict guidelines on how the officer is to conduct the tests, such as an even surface. The officer must demonstrate the test, not skip steps, and have the proper training, or the tests may not be admissible.
Refusing to take a field sobriety test is permitted if the driver has not been arrested. If the driver has been arrested, they could face license suspension. A good defense may be able to find a flaw in the tests.