Should You Decline To Perform Field Sobriety Tests?[1]

Many Colorado drivers will be faced with a decision whether to comply with a request (or a harshly worded demand) by a law enforcement officer to perform a series of roadside field sobriety tests during a traffic stop, and wonder at that moment whether they are legally required to do so. You will suffer no criminal or administrative penalties from exercising your right not to provide law officers with evidence of a crime you might or might not have committed by refusing the tests. (This situation is different from the requirement to submit to a chemical test after an arrest, where refusal to submit may have significant consequences such as revocation of your driver license). However, know that your refusal to submit to Field Sobriety Tests likely will not prevent the officer from arresting you if there is other evidence suggesting your drug or alcohol use (e.g. smell of drugs/alcohol, slurred speech, bloodshot watery eyes, staggering). As a practical matter, the law officer has probably already made some observation that leads him to suspect you are under the influence of drugs or alcohol if he asks you to submit to the tests. Law enforcement officers are attempting to gather enough “objective” evidence with Standardized Field Sobriety Tests to give them probable cause to arrest you and trigger the right to demand you take a chemical breath/blood test. There is no Colorado law requiring you as a driver to submit to any performance field sobriety tests.


The most widely used and frequently studied field sobriety tests are known as the One-Leg Stand, the Walk and Turn, and the Horizontal Gaze Nystagmus tests.

One-Leg Stand – Typically the driver is asked to observe the officer demonstrate the test first and is instructed to mimic performance of the test, otherwise displaying “clues” for failures to strictly comply. The subject must raise one leg approximately six inches off the ground and count starting at 1, or sometimes an alternate number, such as 1,000 (1,001, 1,002 . . .). The driver may be asked to count to as much as 30 on each leg, trying to avoid clues such as counting incorrectly, swaying, extending a hand or showing other signs of poor balance. The officer will tabulate clues for every perceived deviation from this strict performance.

Walk and Turn – Again, the subject is usually instructed to watch the officer demonstrate the test first. The test is performed by walking in a straight line, heel to toe for approximately nine steps, then turning and walking in the same manner back to the start point. The officer tabulates clues for deviations even as slight as the subject raising a hand for balance.

Horizontal Gaze Nystagmus – The officer typically holds a pen about a foot away from the subject, and instructs him to follow the tip of the pen with his eyes. As the officer slowly moves the pen he looks for the subject’s eyes to rapidly twitch or jerk back and forth, particularly before a 45° angle of onset.

These three tests, when administered together, purport to provide a statistically significant probability that the subject (you) is under the influence of alcohol (but not drugs) if you “fail” or exhibit enough “clues” during the tests. These conclusions are based on several studies sponsored by the National Highway Traffic Safety Administration which were conducted and published in the 1970s. There have been many studies and scholarly papers published since that time which tend to refute the conclusion that the standard battery of tests provide reliable statistical evidence of intoxication.

Many courts across the country have held that instructing the subject to perform the tests and the subject’s responses and test performance do not fall under the requirements of the Miranda case. This means that the officer is not required to read the Miranda warnings to the subject driver prior to requesting the field sobriety tests in order to ultimately have the results of that test introduced into evidence in the driver’s later DUI trial (or administrative proceeding).  This is a controversial subject in the criminal law since the driver as a practical matter is not, and does not believe, that he is free to leave, but rather is effectively in law enforcement custody and is being questioned by an agent of the state in a criminal investigation. An assertive defense lawyer will file motions and briefs with the court in a subsequent criminal case to prevent the results of any field sobriety tests, or the subject's refusal to take them, from being used against the driver in trial. However, regardless whether the officer is or is not required to advise a driver of the right against self-incrimination, Colorado citizens should know that they are not required to submit to field sobriety tests.

It is a stark reality that many times a law officer will attempt to coerce a subject into submitting to the tests by using harsh language, demands, or even adopting a soothing tone suggesting that everything will be alright if the driver will just take a few minutes to ensure they are sober, with an implied promise the driver will be released after the tests.  Most people will feel some compulsion to follow the officer’s requests (or demands) and perform the tests in this situation. Minors are particularly subject to this feeling as they have usually been conditioned to trust law officers and follow their instructions. No matter how strenuously a law enforcement officer might pressure a subject to perform the tests, the driver is within their rights to refuse.

In summary, a demand by a law enforcement officer for you to submit to a battery of roadside field sobriety tests is in reality a request that you provide evidence against yourself of a serious criminal offense.  Therefore, you should be aware that you are not required by law to perform roadside field sobriety tests as a Colorado driver, even if you are under 21.

[1] This article is not intended to give legal advice concerning the decision whether to submit to roadside Field Sobriety Tests in Colorado. This article is intended to provide general information only.