Field Sobriety Test
Definition - What does Field Sobriety Test mean?
A field sobriety test is a set of three tests an individual suspected of driving under the influence of alcohol or drugs (DUI/DWI) is asked by law enforcement to perform during a traffic stop. It is used to determine whether the individual is intoxicated. The three tests that constitute the standard field sobriety test are the one-leg stand test, the walk-and-turn test, and the horizontal gaze nystagmus (HGN).
Justipedia explains Field Sobriety Test
In all 50 states, the crime of driving under the influence of alcohol or drugs (DUI/DWI) is defined as driving a vehicle while having blood alcohol concentration (BAC) level of 0.08% or higher. When a law enforcement officer suspects that an individual is driving under the influence, they are generally unable to conduct a blood or urine test on the spot to determine the individual's BAC. The field sobriety test was established by the National Highway Traffic and Safety Administration (NHTSA) to help law enforcement officers determine a driver’s intoxication level. While the walk-and-turn and one-leg stand tests are "divided attention" tests that require a suspect to perform simple physical tasks while following the officer's instructions, the HGN test measures involuntary jerking of the suspect’s eyeball while tracking an object using peripheral vision.
