South Carolina drivers should be aware that they run the risk of being pulled over if they make the decision to drink and drive. In many cases, they may face certain tests that are conducted by officers to determine if they may be too impaired to drive. There are three main tests that authorities use to determine if someone may be under the influence of alcohol: the horizontal gaze nystagmus, or HGN, the walk-and-turn and the one-leg stand.
When an officer is looking for horizontal gaze nystagmus, they are looking for an involuntary jerking of a person’s eyeball. In an impaired person, the eye often cannot smoothly track a moving object, causing the eye to jerk. The object used is usually a flashlight or a pen. In the walk-and-turn test, the person is required to take nine steps, touching their toes to their heels. After the nine steps, they must turn on their heel and face the opposite direction. In the one-leg stand test, individuals are required to stand on one foot while counting aloud by thousands until they are told to stop.
All three of these tests are part of the Standardized Field Sobriety Test. These tests, which were developed at the Southern California Research Institute, can be administered by properly trained police officers in a standardized manner. These tests also provide indicators of potential impairment that have been validated by research. As such, the tests can be used as a probable cause for arrest.
While the field sobriety tests can indicate that someone was driving drunk, there are many reasons that a person may not pass a test but may not actually be impaired. Because these circumstances are unique, those who were taken into custody or may be facing charges are recommended to seek advice from an attorney.
Source: National Highway Traffic Safety Administration, “The Highway Safety Desk Book”, November 22, 2014