The police may pull over drivers under the suspicion that they are drunk driving. To gather evidence against a driver and prove they are inebriated, the police may ask drivers to do a standardized field sobriety test (SFST). There are three kinds of SFSTs:
- Horizontal gaze nystagmus test: The driver must focus their eyes while keeping their head still for this test as an object is moved horizontally around them. The police look for exaggerated involuntary jerking eye movements that might suggest that a driver is drunk.
- One-legged stand test: The driver must lift a leg off the ground until the police tell them to stop. If a driver hops to stay balanced or puts their foot down, then they may be inebriated.
- Walk-and-turn test: Law enforcement may have a driver walk on a line. A driver may have been drinking if they take more steps than instructed or lose balance.
Law enforcement may also ask a driver to do a non-standardized field sobriety test. Here’s what you should know:
How NSFSTs compare to SFSTs
SFSTs are physical examinations sanctioned by the National Highway Traffic Safety Administration (NHTSA). The police typically use SFSTs to gather evidence, but this may not be enough. Drivers may be asked to take non-standardized field sobriety tests (NSFST).
NSFSTs are less commonly used. They may involve a driver, for example, touching their nose, patting their hands, listing the alphabet backward or a vertical horizontal gaze nystagmus test. NSFSTs may be less accurate than SFSTs, but they may still provide evidence against a driver.
Drivers who refuse sobriety tests during traffic stops could face penalties after an arrest. Drivers who believe their rights were violated during a traffic stop may need to learn about their legal defense options.