Most people probably know what a “routine” DUI traffic stop looks like – a law enforcement officer allegedly observes a traffic violation, pulls a driver over, gets suspicious that the driver is under the influence and then conducts field sobriety tests. While, for the suspect, there is nothing “routine” about a DUI stop, there are three common field sobriety tests that drivers can expect. So, what should Colorado residents know about these field sobriety tests?

Many people are already familiar with the “walk-and-turn” test, the “one-leg stand” test and the “horizontal gaze nystagmus” test, the last of which is probably more commonly understood as the “follow the tip of my pen with your eyes” test. Law enforcement officials throughout the country conduct these field sobriety tests in thousands of DUI stops each year. Our readers should understand what, exactly, these tests are meant to help an officer determine.

For starters, the “walk-and-turn” test is conducted by having the suspect walk a straight line, heel to toe, for a certain amount of steps and then return in the same manner. This step tests a suspect’s balance and ability to follow instructions. Next, the “one-leg stand” test is conducted by having the suspect stand on one leg for a certain amount of time without tipping over or setting both feet on the ground. This test, again, tests a suspect’s balance, as lack of balance is one of the key indicators of possible intoxication.

Lastly, the “horizontal gaze nystagmus” test or “follow the tip of my pen with your eyes” test is conducted by having the suspect follow the tip of a pen right in front of the suspect’s face while the pen is moved side to side. The law enforcement officer conducting the test is looking for involuntary jerking in the suspect’s eyes, which can be an indicator of potential intoxication.