What Are Field Sobriety Tests In A DUI Investigation?

Field sobriety tests are a series of tests that law enforcement may conduct during a traffic stop to assess a driver’s impairment by drugs or alcohol. These tests allow officers to evaluate if a driver may be under the influence before making an arrest.

Understanding the routine field sobriety tests can help you not only know what to expect but also handle the encounter more easily.

Standardized field sobriety tests

There are a few standardized field sobriety tests that officers regularly conduct during a DUI traffic stop.

During the horizontal gaze nystagmus test, the officer observes the subject’s eyes as they follow a moving object, such as a pen or flashlight, horizontally to look for involuntary jerking movements. This test measures the effect of intoxication on the subject’s ability to smoothly track movement.

The walk-and-turn test requires you to take a series of heel-to-toe steps along a straight line before turning and repeating the process. During this test, the officer looks for balance issues, missed steps or failure to follow instructions.

The one-leg stand test involves standing on one leg with your arms at your sides while counting out loud for 30 seconds. The officer watches for swaying, using your arms for balance or putting your foot down.

Additional field sobriety tests

In addition to these common methods, officers often ask you to recite the alphabet, touch a finger to your nose or count backward.

Evidence status

Drivers should know that, while field sobriety tests serve as an evaluation tool, the results of these tests do not provide definitive evidence of impairment.

The CDC reports around one million arrests each year for driving under the influence. When you understand the field sobriety tests that factor into these stops, you can assess your experience and consider your defense.