Drunk driving charges oftentimes rely on field sobriety tests which is why it is important that they are reliable. There are three different types of field sobriety tests recognized by the National Highway Traffic and Safety Administration (NHTSA). They must be conducted properly to be considered reliable.

What are the three field sobriety tests?

Following are the three field sobriety tests that are conducted by law enforcement officers during a traffic stop:

  • Horizontal Gaze Nystagmus test: when a driver is impaired by alcohol, the involuntary jerking of the eye when the eyes gaze to the side is exaggerated. The police officer conducting the Horizontal Gaze Nystagmus field sobriety test is looking to see if the driver is unable to follow a moving object smoothly; looking for any eye jerking when eye is at maximum deviation; and looking for any eye-jerking within 45 degrees of center.
  • Walk and Turn test: when a driver is impaired by alcohol, they may have a more difficult time completing tasks when their attention is divided. The police officer has the accused driver take nine steps in a straight line, heel-to-toe, and then the accused driver is required to turn on one foot and repeat the same process in the opposite direction. An inability to complete the process may indicate impairment.
  • One-leg stand test: when a driver is impaired by alcohol they may have difficulty standing on one leg. The police officer will have the accused driver stand on one foot with the foot approximately 6 inches off the ground and count to 30. If the accused driver sways, uses their arms for balance or hops, it may indicate impairment.

Requirements for field sobriety tests

It is essential for field sobriety tests to be properly conducted. The police officer conducting the field sobriety tests must be adequately trained concerning how to conduct the field sobriety test and must administer the test according to the training they have received. If they fail to do so, or are not qualified to administer the test, it may call into question the accuracy and reliability of the test. According to one study by the NHTSA, field sobriety tests are approximately 91% accurate at indicating impairment. Challenging a field sobriety test might be an important part of challenge a DUI charge which is why accused drivers should be familiar with requirements field sobriety tests must meet.