DUI Attorney Chicago Explains Field Sobriety Tests

If you are pulled over for a suspected DUI in Chicago, Cook County, or elsewhere in Illinois, you may be asked to perform a field sobriety test. Your performance on any field sobriety test you take matters. A “failure” could be the justification for an arrest and it could be used against you as evidence of guilt in a criminal DUI trial. With that being said, you are entirely within your rights to decline to participate in a field sobriety test. They are not required by Illinois law. In this article, a top Chicago DUI lawyer explains everything you need to know about field sobriety tests in Illinois. 

What is a Field Sobriety Test?

As a starting point, it is important that drivers in Chicago understand what a field sobriety test is and how they work. Broadly speaking, field sobriety tests are roadside assessments conducted by police officers that are used as part of an evaluation as to whether or not a driver shows signs of impairment. Officers administer these exercises during a traffic stop based on training protocols developed by the National Highway Traffic Safety Administration (NHTSA). To be clear, these are non-chemical assessments. The tests measure physical coordination, balance, and the ability to follow instructions, all of which officers claim correlate with intoxication. Of course, the results of a field sobriety test are inherently subjective. There are three common field sobriety tests in Illinois: 

• Horizontal Gaze Nystagmus (HGN) Test: The HGN test is designed to measure involuntary eye movement. The test is performed by an officer moving a stimulus horizontally across the driver’s field of vision. Officers look for specific clues, including lack of smooth pursuit, distinct nystagmus at maximum deviation, and onset of nystagmus prior to a defined angle. 

• Walk-and-Turn Test: The Walk-and-Turn test evaluates divided attention by requiring the driver to take a series of heel-to-toe steps along a straight line, turn, and return in the same manner. In Chicago, police officers document clues such as stepping off the line, using arms for balance, starting too soon, or failing to maintain the instructed sequence. 
• One-Leg Stand Test: The One-Leg Stand test requires the driver to stand on one leg while counting aloud for a specified period of time. Officers record clues such as swaying, hopping, using arms for balance, or putting the foot down prematurely. Of course, a wide range of non-intoxication-related factors (age, health, etc) can contribute to a driver’s “performance” on the one-leg stand test. 

Field Sobriety Tests are Fully Voluntary Under Illinois Law

Illinois law does not require a driver to perform field sobriety tests during a traffic stop. Indeed, one of the things an experienced Cook County DUI lawyer will tell you is that standardized field sobriety tests are not part of the statutory implied consent scheme set forth under Illinois law (625 ILCS 5/11-501.1). In other words, a Chicago police officer may request participation, but the driver retains the right to refuse without leading to an automatic summary suspension of his or her license. 

Note: A refusal may still influence the officer’s decision to arrest, as officers rely on the totality of circumstances to establish probable cause. 

Understanding the Distinction Between Field Sobriety Tests and Chemical Tests in Illinois

It is important to emphasize that under Illinois law, field sobriety tests differ from chemical tests such as breath, blood, or urine analysis. Chemical testing falls within Illinois’s implied consent statute (625 ILCS 5/11-501.1). That could have big implications for your case. It means that a refusal after arrest can lead to an automatic statutory summary suspension of driving privileges. In contrast, field sobriety tests do not carry the same statutory consequences because they are considered pre-arrest investigative tools. A driver’s decision regarding field sobriety testing should be evaluated separately from the decision to submit to chemical testing. There is no implied consent for field sobriety tests. 

What to Know About Probable Cause for Arrest and the Role of Field Sobriety Tests

You cannot lawfully be arrested for a DUI simply because a police officer wants to do so. An officer must have probable cause to arrest a driver for DUI under Illinois law (625 ILCS 5/11-501). Field sobriety tests serve as one component of that determination, alongside observations such as odor of alcohol, slurred speech, bloodshot eyes, and erratic driving. 

In Illinois, courts evaluate probable cause under a totality-of-the-circumstances standard. In other words, no single factor controls the analysis. A poor performance on field sobriety tests may support probable cause. Still, it does not conclusively establish impairment. Your lawyer may challenge probable cause by identifying alternative explanations for your behavior, such as fatigue, medical conditions, or environmental factors. If you are arrested for drunk driving in Chicago, a DUI attorney for Cook County courthouse can help you determine the best options for raising a defense. 

You Have the Right to Challenge the Reliability of a “Failed” Field Sobriety Test

A failed field sobriety test could be used as evidence in a criminal case. However, there are very big questions about the reliability of these types of tests. For that reason, one of the best DUI lawyer strategies is challenging the test results. Remember, field sobriety tests are inherently subjective and vulnerable to error. Cross-examination often focuses on whether the officer properly instructed the driver, demonstrated the test, and accounted for external conditions such as uneven pavement, poor lighting, or inclement weather. Medical conditions, including inner ear disorders or neurological issues, may produce “clues” that mimic impairment. Illinois courts permit defense attorneys to attack the foundation of the officer’s testimony by highlighting deviations from training standards and inconsistencies in the reported observations. A Chicago DUI defense lawyer can review your specific case and help you determine your options for challenging a field sobriety test. 

The Chicago DUI Attorneys is a boutique law firm committed to protecting the rights of drivers. A DUI charge is a serious matter in Illinois. Being arrested and charged with a drunk driving offense is stressful, but it is not the end of the road. Do not go it alone: Contact a Chicago DUI lawyer today for a completely confidential, no obligation initial consultation.