You may be driving home from a party, a night out on the town or a wedding when suddenly you see red and blue lights flashing in your rear-view mirror. Before you know it, a police officer has pulled you over and asked you to perform a field sobriety test to determine if you are driving under the influence.

Field sobriety tests are not all created equal. Because there is always an element of subjectivity, in general police in Michigan rely on three standard tests endorsed by the National Highway Traffic and Safety Administration: the horizontal gaze nystagmus test, the walk-and-turn test and the one-leg stand test.

In the horizontal gaze nystagmus test, officers will have the motorist follow a moving object, such as their finger or a light. Officers will note whether the motorist can follow the object smoothly and whether the motorist’s eyes jerk in a way that is exaggerated due to alcohol use.

In the walk-and-turn test, the motorist will be asked to take nines steps in a row along a straight line, heel-to-toe. Then the motorist will have to turn around and do the same thing in the other direction. This task is generally easy for a sober person, but a person who is under the influence may sway or stumble.

In the one-leg stand test, the motorist will be asked to put one foot about six inches in the air for 30 seconds. Officers will note whether the motorist is able to stay balanced when doing so, to determine whether the motorist is under the influence of alcohol.

It is important to note that even though these tests are standardized, there is still an element of subjectivity involved. Also, some officers will fail to utilize these standardized tests and instead will rely on more unreliable tests such as counting fingers, reciting the alphabet or touching one’s nose with one’s eyes closed. Whenever a motorist is charged with drunk driving following a field sobriety test alone, the motorist may wish to challenge such charges. Attorneys in the Grand Rapids area understand how these tests can sometimes be faulty and may be a useful resource.