Illinois Standardized Field Sobriety Tests

Standardized Field Sobriety Tests in Illinois

The majority of Illinois DUI arrests are based in part on the Standardized Field Sobriety Tests. The goal of this page is to help you understand the basis for these tests, and give you a glimpse of how Carbondale, IL criminal lawyer Brian Roberts challenges each of them in court. Every IL DUI case is different, and the facts of your case may be outside the scope of what is discussed on this page.


The walk-and-turn (WAT) field sobriety test requires you to stand with the heel of your right foot touching the toe of your left foot, with your arms by your side while the officer gives you the instructions. After the officer has instructed you, you are required to walk nine steps down a real or imaginary line, touching heel-to-to, counting your steps out loud, keeping your arms by your side, looking at your feet, and without losing your balance. Once you take nine steps you are to turn slowly in a controlled manner and return back down the line the same way you just walked up the line. There are six possible clues of intoxication in this test. Learn more on our IL DUI Walk-And-Turn page… IL DUI Walk-and-Turn

One Leg Stand

The one leg stand (OLS) field sobriety test requires you to stand with your feet together, with your arms by your side while the officer instructs you on how to perform the test. After the officer instructs you to begin you are to raise the foot of your choice approximately six inches off the ground, look at your toe, and begin counting 1001, 1002, 1003, and so on until the officer tells you to stop. The officer is supposed to stop you after you have stood in that position for thirty seconds. Learn more on our IL DUI One Leg Stand Page… IL DUI One Leg Stand Test

Horizontal Gaze Nystagmus

The horizontal gaze nystagmus (HGN) test is considered the most reliable indicator of intoxication out of the three standardized field sobriety tests. The officer will have you stand with your feet together and your arms by your side while he waves his finger, an ink pen, or other object from side to side in front of your nose. The officer is looking for an involuntary jerking of the eyes that is said to be caused by alcohol intoxication. He may also turn the object you are following sideways and raise it above your head and back down a time or two. This vertical test is not part of the HGN examination, but is often performed by officers. Learn more on our IL DUI Eye Test page… Illinois DUI Eye Test

Carbondale, IL criminal defense attorney Brian Roberts is skilled an knowledgeable about all aspects of evaluating the officer’s administration of the Standardized Field Sobriety Tests. Do not believe that just because the officer told you that you failed the SFST’s or that the SFST’s indicated you were impaired that such conclusions are accurate. Call now for a free, confidential consultation!