DUI Field Sobriety Tests
Field sobriety tests are roadside exercises police officers ask those suspected of drunk driving to perform in order to judge their ability to safely drive a vehicle.
A police officer’s interpretation of how you performed on a field sobriety test can be used to establish probable cause either to arrest you for driving under the influence, to ask you to perform a breathalyzer test, or to ask you to submit to other chemical blood alcohol tests such as urine or blood draws.
While slurred speech is often the first indicator that a driver has been drinking, police officers have a series of tests that they can turn to in order to determine whether a driver may be impaired.
A word to the wise: beginning the test before the officer completes the instructions or not being able to keep your balance during the instructions can both be interpreted as signs of impairment.
The most commonly administered field sobriety tests include the following:
- Alphabet: The driver is asked to say the alphabet, forwards or backwards. Any skipping of letters or even hesitation can be interpreted as signs of impairment.
- Counting: The driver is asked to count in patterns, forwards or backwards, such as “Count backwards from 20 in threes.” Any skipping of numbers or overt difficulty in performing the task can be interpreted as signs of impairment.
- Finger to Nose: The driver is asked to stand with his arms outstretched, head back, and eyes closed. Then he is supposed to touch his finger to his nose, first with one hand, then the other. Swaying, stumbling, losing one’s balance, or otherwise being unable to complete the test satisfactorily can be interpreted as signs of impairment.
- Horizontal Gaze Nystagmus: The driver is asked to track a slowly moving object with his eyes; the officer looks for exaggerated “horizontal gaze nystagmus,” the involuntary jerking of the eye that happens when the eyes look from one side to the other.
- Line Walk: The driver is asked to walk in a straight line; swaying, staggering, losing one’s balance, or otherwise being unable to complete the test satisfactorily can be interpreted as signs of impairment.
- One Leg Stand: The driver is asked to stand on one leg with the other foot about six inches from the ground; he is to count out loud (one thousand one, one thousand two) until the officer tells him to put his foot down at around thirty seconds. Swaying, stumbling, losing one’s balance, making mistakes in counting, or otherwise being unable to complete the test satisfactorily can be interpreted as signs of impairment.
- Standardized Field Sobriety Test (SFST): The driver is asked to perform a series of three tests (horizontal gaze nystagmus test, walk and turn test, and one-leg stand test).
- Walk and Turn: Similar to the line walk, a driver is asked to first asked to walk heel-to-toe for nine paces along a straight line, then must turn on one foot and walk in the same manner in the opposite direction. Swaying, stumbling, losing one’s balance, taking the wrong number of steps, stopping to regain composure, not touching heel-to-toe, or otherwise being unable to complete the test satisfactorily can be interpreted as signs of impairment.