When California law enforcement officers pull you over for allegedly driving under the influence of alcohol or drugs, they have the right to ask that you undergo a field sobriety test. You, on the other hand, have the right to refuse to take this test. California law does not mandate your taking it, nor will you face any penalties for doing so. 

In fact, your best interests dictate that you decline to take a field sobriety test. Why? Because you can fail it for several reasons, including the following, even when sober: 

  • Your age and/or weight 
  • The type of clothing or shoes you wear 
  • Medical problem(s) 
  • Medication(s) 
  • Incorrect instructions the officer may give 
  • Improper observations the officer may make 

Also, the field sobriety test consists of three separate tests: the horizontal gaze nystagmus test, the walk-and-turn test and the one-leg stand test. 

Horizontal gaze nystagmus test 

Your eyes involuntarily jerk when you gaze to the side. This phenomenon goes by the name of horizontal gaze nystagmus and usually becomes more pronounced after you drink or take drugs. In the HGN test, the officer instructs you to visually track a moving object, such as a pen or flashlight, without moving your head while the officer slowly waves the object horizontally in front of your face. (S)he looks for at least three indications of your impairment: that your eyes cannot smoothly track the object, that they distinctly jerk at each end of the movement and/or that they begin jerking before the object moves 45 degrees one way or the other. 

Walk-and-turn test 

In the walk-and-turn test, the officer instructs you to take nine steps along a straight line, touching your feet heel-to-toe. After nine steps, (s)he instructs you to turn on one foot and return to your starting position, again taking nine steps and walking heel-to-toe. (S)he looks for at least eight indications of your impairment, including your inability to maintain your balance while walking and/or turning. 

One-leg stand test 

The final segment of the three-part field sobriety test requires you to stand on one foot while holding your other foot about six inches off the ground while you count for about 30 seconds. The officer looks for at least four indications of your impairment: failing to maintain your balance, using your arms to help you maintain it, putting your lifted foot down and/or hopping.