Most drivers know that field sobriety tests are routine for most traffic stops, especially if you’re frequently driving on Friday or Saturday nights.

However, few drivers understand the validity of these tests and the possibilities to challenge any questionable results.

A Field Sobriety Test Breakdown

Before you can challenge any results, you need to know what the tests are and where their faults lay. In California, officers may use any or all of the three types of tests that have been studied and approved for use by the National Highway Traffic and Safety Administration:

  • One-leg stand – a driver will stand on one foot with the foot hovering six inches off the ground for 30 seconds. The officer looks for signs of imbalance, lack of coordination and hopping as signs of impairment.
  • Walk and turn – The officer will ask the adult to take nine steps, heel-to-toe, along a straight line. Then, the person will turn on one foot and return in the same manner.
  • Horizontal gaze  – Officers will ask a driver to look into their eyes or follow an object with just their eyes to see signs of involuntary jerking or inability to follow the object smoothly.

All three tests are standardized and used by law enforcement agencies across California. However, each test has holes that could be poked at during a DUI case. For example, if you perform the one-leg stand on an uneven surface, it will make balance difficult, creating ambiguous results. Also, the type of shoes a driver wears or the weather conditions may influence the outcome of a specific test.

The variability doesn’t stop there. Officers may try to conduct tests differently or even use non-standardized methods to determine impairment. In these cases, you may be able to argue why the results are questionable, potentially giving you and your attorney an opportunity to build a strong defense against the charges.

Motorists do have the option of declining field sobriety tests which may limit the evidence available to support allegations of drunk or drugged driving. You may wish to refuse these tests to prevent the officer’s likely negative interpretation of those tests being used in your case against you. Know that if you decline the tests, the traffic stop and subsequent investigation by responding officers may continue, and in many cases, will lead to an arrest, but this could help you as you look for opportunities to defend against the charges you are facing.