What Are Field Sobriety Tests?

During a traffic stop a Wisconsin driver may be subjected to field sobriety tests. Field sobriety tests are administered when law enforcement officials suspect that drivers are operating their vehicles while under the influence of intoxicants like alcohol. If a driver fails a field sobriety test that information may be used against the person in a drunk driving trial.

Law enforcement officials can administer a number of tests to investigate for evidence of intoxication in a driver. There are several standard tests, however, and this blog post will discuss a few of those tests. The first test to be discussed is the horizontal gaze nystagmus.

During the horizontal gaze nystagmus test a law enforcement official may look to see if a driver's eye movements are smooth or irregular. Irregular or jerky eye movements may demonstrate intoxication in a driver; it is important to remember, however, that other factors can influence how a driver performs under this field sobriety test.

Next, some drivers are subjected to the one-leg stand field sobriety test. The one-leg stand test is pretty much what it sounds like -- a driver is asked to stand on one leg while lifting the other off of the ground. This test can demonstrate a driver's coordination or lack thereof. Factors other than alcohol can affect how a driver's balance and coordination are evaluated by a law enforcement official.

The final most common test that a driver may face is the walk and turn test. A driver is asked to walk heel to toe in one direction and then turn around to do the walk in the other direction. Uneven ground, illness and other factors can cause an otherwise sober driver to struggle with this test.

There are other field sobriety tests that drivers may be asked to perform. Each test serves as a way for law enforcement officials to seek out evidence of intoxication from suspected drunk drivers. However, no field sobriety test is perfect and in some cases sober drivers are charged with drunk driving when these tests provide inaccurate evidence against them.