Law enforcement may have strong suspicions that a driver is drunk during a traffic stop. This could come from slurred speech, alcohol smell or other signs of inebriation. To gather evidence for a drunk driving charge, the police may ask drivers to perform field sobriety tests.
Several field sobriety tests are recognized by the National Highway Traffic Safety Administration (NHTSA). These tests allow the police to judge whether a driver shows signs of inebriation through a series of physical activities. If asked to do a field sobriety test, it is often important to follow police instructions. There are three popular forms of field sobriety tests, including:
Horizontal gaze nystagmus test (HGN)
To do a horizontal gaze nystagmus test, the police may ask the driver to keep their eyes focused on the tip of a finger, pen or light. The police will then move the object from side to side. The driver is meant to follow the object without turning their head. With a HGN test, the police are looking to see if the eyes jerk. If the eyes jerk a lot, the driver may be inebriated.
Walk-and-turn test (WAT)
A walk-and-turn test often begins with having a driver stand on a straight line. The driver may then be asked to walk up the line several paces. The police should then ask the driver to walk back. If the driver falls over or steps off the line, the police may believe the driver is drunk.
One-legged stand test (OLS)
The police may ask a driver to do a one-legged stand test. To do an OLS test, the driver may need to lift one leg off the ground and keep their position for several seconds. If the drivers put their foot down or fall over during the test, the police might assume they are inebriated.
Field sobriety tests are not always accurate. Drivers can challenge the results of field sobriety tests. Legal guidance can help a driver develop a strong defense.