If you are pulled over due to suspicions that you are driving under the influence, the responding officer may request a breathalyzer test to determine your blood alcohol content. You may also be asked to complete a field sobriety test, which involves three types of tests.
It is important for law enforcement to perform and assess tests correctly so that your rights are preserved. The following guide explains how each test works and what officers look for when conducting them.
The walk-and-turn test
This test entails taking nine heel-to-toe steps in a straight line, stopping, and turning to take nine more heel-to-toe steps in the opposite direction. While performing the walk-and-turn test, the officer will look for certain signs of inebriation. Signs include problems maintaining balance before the test, beginning before instructions are complete, stopping to regain balance when walking, not walking heel-to-toe, stretching arms for balance, stepping out of line, taking the wrong number of steps, and turning incorrectly.
The one-leg stand test
The officer performing the one-leg stand test will request that you raise one foot off the ground approximately six inches while holding for a certain amount of time. While holding the position, you will be asked to count by one thousand for 30 seconds. The officer will look for outstretched arms, hopping on one foot, swaying, and putting the elevated foot down.
The horizontal gaze nystagmus (HGN) test
The HGN test looks for involuntary eye movements that typically indicate inebriation. This test is conducted using a penlight or other object, which will be passed in front of your eyes. You will be asked to track the object with your eyes, during which the officer will look for certain cues of inebriation. These include trouble following the object and jerking eye movements before the object reaches 45 degrees of center.