Standardized Field Sobriety Tests for DUI in Tennessee
What are standardized field sobriety tests?
When performing a traffic stop for suspected DUI, police in Tennessee often ask the driver to step out of the vehicle and perform field sobriety tests. The standardized field sobriety tests (SFSTs) are a battery of mixed physical-mental tasks that are administered to a subject to gauge the subject’s level of alcohol impairment. These include the following:
- Horizontal gaze nystagmus (HGN). The first test that is typically administered is the Horizontal Gaze Nystagmus (HGN) test, in which the police officer observes the test subject’s eyes. During this test, the officer looks for involuntary jerking of the suspect’s eyes as they gaze toward the side. The officer checks for: lack of smooth pursuit of the eyes, distinct and sustained nystagmus at the eyes’ maximum deviation, and nystagmus starting before the eyes reach 45 degrees.
- Walk and turn. The second test that is usually administered is the Walk and Turn Test (WAT) test. This test measures the suspect’s ability to maintain their balance, walk in a straight line, and follow directions.
- One leg stand. The One Leg Stand (OLS) test requires the suspect to stand on one leg for 30 seconds and also measures balance, coordination, and similarly to the WAT test, divides the suspect’s attention.