Difficulty: Moderately Challenging
Step1
Know the most commonly used tests used by officers who suspect a driver is drunk. These are the horizontal gaze nystagmus (HGN), the walk and turn and the one-leg stand. You could also be asked to perform a number of other tests, including the touching your finger to your nose and reciting the alphabet backwards.
Step2
Follow the object, usually a pen or small light, the officer moves back and forth horizontally in front of you moving only your eyes. This tests your HGN, or the involuntary jerking motion your eye makes when looking to the side. For a person who's been drinking this motion is more pronounced. There isn't anything you can consciously do to control this other than not drink past the legal limit.
Step3
Walk and turn as directed by the officer. This test usually consists of walking nine steps in a straight line and stepping heel to toe, after which you'll be asked to turn on one foot and perform the same task going in the other direction. This tests your balance and your ability to listen to and follow instructions. An officer will conclude you're impaired if you have to use your arms to balance, if you hesitate to regain balance, if you don't touch your heel to your toe, if you take the wrong number of steps or if you begin before all the instructions are given. Keep all of these points in mind while performing this test.
Step4
Stand on one leg and count as instructed by the officer. Your leg will be required to be about six inches off the ground and you'll need to count out loud saying "one-thousand one, one-thousand two," and so on. This will often last about half a minute before the officer will tell you to put your leg down. Indicators that a person has been drinking are any type of balance loss.