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Is a field sobriety test always accurate?

Many factors may inhibit a person’s ability to successfully pass a field sobriety test even if they have not consumed alcohol.

Georgia residents likely know that there is strong public sentiment against people tagged as drunk drivers. However, at the same time it is completely socially acceptable for people to attend social functions at which alcohol is served and then drive themselves home.

These competing realities make it all too easy for any driver to be suspected of impaired driving by a law enforcement officer. If during an otherwise routine traffic stop, alcohol or drug use is suspected by an officer, a driver may be asked to participate in field sobriety tests. It is important for people to know what these tests measure and that they are not always accurate.

What field sobriety tests measure

As explained by, there are three different tests approved for use in a standardized manner by the National Highway Traffic Safety Administration. Despite what some people might believe, these tests do not and cannot prove that a driver is drunk or impaired by drugs.

Instead, these tests are used to indicate that there is a possibility of impairment. This possibility provides ample evidence to legally support a criminal arrest. When hearing reports that drivers have failed field sobriety tests people might wonder what that means.

Examples include the story from Northwest Georgia News about a woman who “failed a field sobriety test during a traffic stop.” No other details about these tests are known. Another example is the case of a man who was found asleep in a drive thru and later said also only that he failed the field test.

Three types of tests used

One of the tests used measures an involuntary jerk of the eye. This motion might be more noticeable if a person has been drinking. However, it might also be more pronounced in people with certain neurological conditions.

Two other tests evaluate balance and the ability to perform multiple tasks simultaneously in different ones.

In the one-leg stand test, a person must balance perfectly on one leg while holding the other in the air. Arms must remain firmly at the driver’s sides while they count out loud until instructed to stop. The walk-and-turn test requires a person to take steps in a heel-to-toe fashion, turn around and return to the original location.

People who are overweight or who have problems with their legs, back, hips or feet might not be able to execute these tasks even if they have not been drinking. The accuracy rates of the field sobriety tests range from 65 to 77 percent.

Legal help is important

Knowing that the tests used during a drunk or drugged driving stop may not be accurate is just one of the reasons that a Georgia resident arrested for driving under the influence should always contact an attorney for defense assistance.