First, never drink and drive. If you choose to drink, stay home or make sure that you have a designated driver. We want for our community to be as safe as possible.

Both sober and intoxicated drivers are pulled over by law enforcement every day.  While most traffic stops are routine, sometimes drivers are accused of driving under the influence. (DUI). While advice varies from case to case, one thing is constant when a person is the subject of a DUI investigation; do not ever take any Field Sobriety Tests.  (FSTs).

FSTs were developed by police agencies to assist law enforcement officers in making roadside determinations as to whether a driver is under the influence of alcohol or drugs. Through the performance of these tests or evaluations, the officer subjectively determines how the motorist reacts to and performs the tests.

FSTs are also 100 percent voluntary. No one can make a person submit to roadside tests.  Regardless of the circumstances, when asked to perform any FST, always politely let the officer know that you decline. 

Sometimes, a driver will feel like FSTs are mandatory.  This is because officers are trained to “urge” drivers to engage in FSTs without actually commanding them to do so.  The officer has no legal duty to apprise the driver that the tests are voluntary.

The three most common tests are (1) the walk and turn test, (2) the one leg stand test, and (3) the horizontal gaze nystagmus (HGN) test.

The HGN test is administered when an officer holds a pen in front of the driver’s face and asks him to follow it from side-to-side without moving his head. The officer is looking for any shaking motion (nystagmus) in the eyes.  Nystagmus can be an indication that the driver may have consumed alcohol. A non-intoxicated person may track the pen’s motion with a more fluid movement.

People with eye problems have trouble passing this test. Nystagmus naturally occurs in some people’s eyes.  Even a driver with a cup of coffee can fail this test because many other chemicals, like coffee, can create nystagmus. 


Another common test is the walk and turn.  The motorist will be asked to stand still, and upon the officer’s command, start to step forward while placing heel-to-toe and walk a straight line for a certain number of paces.

Then, the officer will instruct the driver to turn around and walk back to the starting point. Any indication of being wobbly, not beginning when instructed, or stumbling can lead to an arrest.

The one leg stand is the other dexterity test.

Keep in mind that you are not allowed to practice any of these tests. The camera will be recording your first attempt at these dexterity tests.  If you think they are easy to perform, try the walk and turn and the one leg stand at home. You may be surprised at the results. 

Another FST, that should not be confused with the Intoxilizer 9000 (the breath testing machine at the police station), is the portable breath testing device, or “alcosensor.” This alcohol screening device can detect the presence of alcohol if it has been properly calibrated. However, like other FSTs, these devices used at the roadway should be politely declined.

Since over 90 percent of DUI cases involve the driver performing FSTs, the lawyer for the defense must challenge the subjective nature of the evaluations, the accuracy of the principles behind the tests, the accuracy of the administration of the tests, and challenge all circumstances connected with the evaluations. As I said in the beginning, don’t drink and drive in the first place. However, not every person accused of drinking and driving is guilty of the offense. If you ever find yourself in a situation where you are being investigated for DUI, remember that you should never agree to perform any field sobriety test.