What are field sobriety tests?

What are field sobriety tests?

Most Wisconsin residents have heard references to field sobriety tests before and know that they are somehow related to the drunk driving arrest process. But, many people do not really know what these tests entail nor how possible the chance for them to be inaccurate it. Understanding this is important for all drivers as a means of being prepared ahead of time should they ever be faced with participating in such testing.

The National Highway Traffic Safety Administration outlines details of the three individual tests that together create what is known as the Standardized Field Sobriety Test for persons suspected of operating under the influence of alcohol. These are as follows:

  • In the Walk-and-Turn test, drivers are required to take nine steps in a straight line. Feet must be placed with the heels of the front feet touching the toes of the back feet as they move. After nine steps, they are to turn around and return in the same fashion.
  • The One-Legged Stand is similar to the Walk-and-Turn in that it also requires balance. Drivers must successfully count out loud while standing on only one foot for 30 seconds.
  • People naturally experience some muscular jerking when their eyes are moved far to the sides and this is said to be more pronounced when not sober. The Horizontal Gaze Nystagmus test has officers move an object from side to side which drivers must follow with their eyes only to measure the level of this jerking.

In the first two tests, things like stopping, use of arms for balance, putting a foot down momentarily or failure to maintain a straight line can be considered signs of impairment. In the eye test, inability to track the item could lead officers to request breath test data or other determinations of BAC levels.

Many things can affect the reliability of these tests and their outcomes do not always indicate true impairment. This information is not intended to provide legal advice but general information regarding field sobriety tests.