Field Sobriety Tests In Illinois

Picture this: You’re driving home after dinner with friends when red and blue lights suddenly flash in your rearview mirror. Your heart pounds as you pull over. The Lake County Sheriff approaches and asks if you’ve had anything to drink. You say no—but then comes the dreaded question:

“I need you to step out of the vehicle and perform a few tests.”

Field Sobriety Tests (FSTs) are designed to help police officers determine whether a driver is under the influence of alcohol. But here’s what most people don’t realize—these tests aren’t foolproof. Even sober individuals can fail due to medical conditions, nervousness, or uneven pavement. Knowing your rights and understanding how these tests work can make all the difference if you ever find yourself in this situation.

What Are Field Sobriety Tests and Why Are They Used?

Field Sobriety Tests are physical and cognitive exercises conducted on the roadside to help officers determine if a driver is intoxicated. The goal? To quickly assess impairment without immediately resorting to a breathalyzer or blood test.

In Lake County, Illinois, police officers use a mix of standardized and non-standardized tests—some of which are backed by scientific research, while others are less reliable.

Before conducting any test, officers should ask if you have a medical condition that might affect your ability to perform them. If they don’t, their results could be challenged later in court.

Standardized Field Sobriety Tests (SFSTs)

These tests are approved by the National Highway Traffic Safety Administration (NHTSA) and are considered the most reliable indicators of impairment. However, even these are not 100% accurate and can be influenced by external factors.

Walk-and-Turn Test

• The driver must walk heel-to-toe in a straight line, turn, and walk back.

• Failing to stay balanced, stepping off the line, or struggling to turn smoothly may be seen as signs of intoxication.

Problem: Many factors can cause failure—uneven pavement, uncomfortable footwear, or even anxiety.

Horizontal Gaze Nystagmus (HGN) Test

• The officer moves a pen or flashlight in front of your eyes, watching for involuntary jerking movements.

• If your eyes twitch excessively while following the object, officers may suspect impairment.

Problem: Some people naturally have eye conditions that cause nystagmus, even when completely sober.

One-Leg Stand Test

• You must stand on one foot for about 30 seconds while keeping your balance.

• Swaying, using arms for balance, or putting your foot down can be seen as clues of intoxication.

Problem: Many medical conditions, injuries, or even fatigue can cause balance issues, leading to a false failure.

Non-Standardized Field Sobriety Tests

These tests are not scientifically validated, meaning they are even less reliable in proving intoxication. However, some officers still use them as additional evidence.

Finger-to-Nose Test

• With your eyes closed, you must touch your nose with your index finger.

• Missing your nose could be taken as a sign of impairment.

Problem: Poor coordination, nervousness, or even cold weather can affect performance.

Romberg Balance Test

• Stand with feet together, close your eyes, and estimate when 30 seconds have passed.

• Overestimating or underestimating time may be interpreted as intoxication.

Problem: Many sober people struggle with time estimation and balance, especially if standing on an uneven surface.

Finger Count Test

• Touch each finger to your thumb while counting in order.

• Hesitation, miscounting, or errors might be seen as signs of impairment.

Problem: Stress and fatigue can affect performance, even in a completely sober individual.

Can Field Sobriety Tests Be Used Against You in Court?

Yes. If you fail an FST, prosecutors will use it as evidence to argue that you were impaired. However, a skilled DUI attorney can challenge these results by pointing out:

• The officer’s improper administration of the test

• The unreliability of non-standardized tests

• Medical conditions or external factors that could have affected performance

Do You Have to Take a Field Sobriety Test in Illinois?

No! If you are pulled over, you can politely refuse to take a field sobriety test. However, always remain respectful and comply with any lawful orders from the officer.

Unlike chemical tests (which have automatic penalties for refusal), declining a field sobriety test does not result in immediate license suspension.

Why might refusing be a good idea?

• These tests are subjective – Officers use their own judgment to decide if you “pass” or “fail.”

• Failing gives them more evidence against you – Even if you’re sober, struggling with balance or coordination can make you look impaired.

• Refusing limits their case – Without field sobriety test results, prosecutors have less evidence to use against you.

What Happens If You Refuse a Field Sobriety Test?

• The officer may still arrest you based on other observations (like slurred speech or the smell of alcohol).

• You may be taken to the station and asked to take a breathalyzer or blood test.

• But most importantly: You are not automatically guilty just because you refused.

Field Sobriety Tests can be unreliable, subjective, and even unfair. Even sober people can fail due to nervousness, medical conditions, or uneven terrain. You have the right to refuse these tests, and doing so may actually work in your favor. Stay informed, stay prepared, and always make smart decisions on the road.

If you ever find yourself facing DUI charges after a field sobriety test, don’t panic—get legal help immediately. Contact Alan Lenczycki, an experienced Lake County DUI attorney, who can review the evidence and potentially challenge the validity of these tests to protect your rights.