The police can ask drivers whether they have been drinking during traffic stops. If the police do not gather enough evidence by asking drivers questions, they may ask drivers to perform field sobriety tests. Field sobriety tests make drivers move around in ways that would be difficult if they were inebriated.
There are four kinds of field sobriety tests (FSTs). Three kinds of field sobriety tests are considered standardized, which means they are recognized by the National Highway Traffic Safety Administration. Here is what you should know about all four tests:
1. Horizontal gaze nystagmus test (HGN)
A common kind of field sobriety test is the horizontal gaze nystagmus test. The HGN test evaluates a driver’s eye focus. The police will move an object in front of the driver’s face. The driver will try to hold their focus without moving their head. If the driver struggles to stay focused, they could be inebriated.
2. One-legged stand test (OLS)
A driver asked to do a one-legged stand test must lift up on leg off the ground. The driver will keep that leg up for the duration of the OLS test, which often only lasts a few seconds. If the driver puts their foot down or falls over, the police may suspect them of being drunk.
3. Walk-and-turn test (WAT)
A walk-and-turn test has a driver walk on a line several paces from where they started. Then, the driver will return to where they started. If the driver steps off the line, falls over or fails to do as instructed, they could be arrested for drunk driving.
4. Non-standardized field sobriety tests (NSFST)
Any other kind of field sobriety test may be considered non-standardized. For example, if a driver is asked to touch their toes or place a finger on their nose.
A field sobriety test does not always mean a driver is drunk. Medical conditions, medicine and disabilities may make it harder for the police to judge a driver’s condition.
