Field Sobriety Tests

While there are a multitude of non-standardized field sobriety tests (FST), there are only three that have been validated by the National Highway Traffic Safety Administration.  Non-standardized tests are meant to see how a person suspected of driving under the influence performs.  Examples include balance tests, reciting a portion of the alphabet, counting backwards and other tests which challenge the agility, dexterity, and concentration of a person who is intoxicated.

The three standardized tests are the horizontal gaze nystagmus ("eye test"), the one-leg stand, and the walk and turn.  A law enforcement officer can use these tests to give them the right to detain a driver as having reasonable suspicion of being under the influence.  If you have been charged or arrested for DUI, you should seek the representation of an Orange County DUI lawyer as soon as possible. 

How the Standardized Tests Are Performed

The horizontal gaze nystagmus, or HGN, is a fairly simple test that involves the officer having the driver follow a pen from side to side.  The driver is to follow the pen with his eyes only while keeping his or her head facing forward.  The officer is looking for involuntary eye twitches (nystagmus) and difficulty tracking the pen.

In the one-leg stand, the suspected drunk driver is asked to stand in place while holding one foot about six inches from the ground.  The driver is also told to count out loud while keeping this position.  This tests the person's balance and concentration.

The walk and turn test involves walking nine steps heel-to-toe in a straight line, doing an about face and returning in the same manner.  The officer is looking for any balance difficulties or inability to follow instructions.

Charged with DUI in Orange County?

Even the standardized tests have weak points and there are many factors that could cause a person to fail a FST.  An attorney may be able to show how nervousness, prescription medication, a pre-existing physical condition, or any number of circumstances could have been the cause.  Every case is different so do not hesitate to call today!