About Field Sobriety Tests

Sobriety Tests: Methods for Determining Intoxication

Field sobriety tests are essentially roadside sobriety tests that consist of performing certain agility exercises in order to determine if a driver is intoxicated. There are currently three field sobriety tests that are recognized by the National Highway and Traffic Safety Administration as "valid", and officers in Seattle commonly rely on these tests to gather evidence for a DUI arrest.

In order for these tests to be "valid" and used as evidence in a DUI case, they must be administered by a police officer in the manner prescribed and standardized by NHTSA. In some cases, police officers will also conduct additional tests that are not validated by the NHTSA, but these tests cannot be used in court.

Types of Field Sobriety Tests

1. The Horizontal Gaze Nystagmus: This test examines the movements of the eyes. During this test, a police officer will ask you to step out of the car and follow a stimulus with your eyes. The officer will be looking for jerking of the eyeball while following the stimulus or while at rest, or the jerking of the eyeball when it reaches the farthest point that it can move to the side. This test is not foolproof because nystagmus can be caused by many other things besides intoxication, such as head injuries, foreign fluid in the body or tired eyes.

2. The Walk and Turn: Officers will also use the Walk and Turn field sobriety test in order to determine intoxication. The police officer will typically ask you to picture an imaginary line and then take heel-to-toe steps while counting out loud and making turns when the officer asks you to. You will fail the test if you do more than one of the following:

  • Start the test too early
  • Step off the imaginary (or real) line
  • Stop walking during the test
  • Raise your arms from your sides more than six inches, or other actions

3. The One Leg Stand: Similar to the Walk and Turn, the One Leg Stand field sobriety test also requires drivers to follow specific directions. You will be asked to raise on leg six inches from the ground while keeping both legs straight and counting until you are told to stop. There are numerous ways that you can fail this test as well, especially if you have bad balance.

Problems with Field Sobriety Tests

Field sobriety tests were created to indicate whether you have been driving under the influence of drugs or alcohol, but there are other physical conditions that may negatively affect your performance on these tests regardless of whether or not you have consumed alcohol. Certain illnesses and other medical conditions can affect balance and coordination, and test anxiety can affect performance as well. Studies have revealed that size, age and gender of drivers can also affect mental and coordination abilities.

One of the key defense strategies for DUI charges in Seattle involves challenging the manner in which the police officer administered a field sobriety test. As a driver, you should keep in mind that you are not required by Washington State law to take these tests, and you should respectfully decline these tests so that evidence cannot be used against you. The only tests that you are actually required to take are the evidential chemical tests that are administered at the jail, hospital or police station.