Why are field sobriety tests inaccurate?

Field sobriety tests are physical evaluations that can help the police determine if a driver is drunk. There are four kinds of field sobriety tests:

• Horizontal gaze nystagmus test: This test evaluates a driver’s focus. The driver will be asked to keep their eyes on a finger, pen or light and watch it as it moves.
• One-legged stand test: The officer may ask the driver to stand on one leg for a few seconds. The officer is determining the driver’s ability to keep balances, which they may struggle with if they were drinking.
• Walk-and-turn test: The driver may be asked to walk in a straight line. If they fall or go off the line, it could be a sign of intoxication.
• Non-standard field sobriety test: The first three tests are considered standard and are sanctioned by the National Highway Traffic Safety Administration. Any other tests, such as saying the alphabet backward, would be considered non-standard.

Why would a police officer ask you to do a field sobriety test?

The police can use the results of a field sobriety test as additional evidence to prove a driver is intoxicated. However, these tests aren’t always accurate. Here’s why:

Determining intoxication from disabled

Field sobriety tests may help the police determine if someone is drunk. But, someone who has a disability could fail these tests even if they’re sober. For example, someone with a leg impairment may struggle to walk in a straight line or stand on one leg for any duration of time.

An officer may have struggled to determine if a person is intoxicated or has a disability. As a result, a driver could suffer from a drunk driving charge and need to seek legal help to clear their name.