Ohio Field Sobriety Tests: HGN, Walk-and-Turn & Your Rights

It is important to realize that you do not have to take the standardized field sobriety tests. Why would you? If an officer makes the determination that you are drunk by getting you out of the car, why would you think you could change his/her mind. You can’t!

In this section, we will discuss Ohio’s infamous “Standardized Field Sobriety Tests,” which we also know as roadside tests, or stupid human tricks. These tests are used by an investigating police officer to determine whether or not probable cause exists to believe that a driver is impaired by drugs and/or alcohol. Police officers learn the standardized field sobriety tests as they are set forth by the National Highway Traffic Safety Administration in their various manuals.

The Three Standardized Field Sobriety Tests

Police officers learn the Standardized Field Sobriety protocol at the academy or by completing a “Participant” class after they are sworn in. They learn three of the most common standardized field sobriety tests, which are: (1) horizontal gaze nystagmus (HGN), (2) walk-and-turn (WAT), and (3) one-leg-stand (OLS). Officers can receive additional training at the Advanced Roadside Impaired Driving Enforcement (ARIDE) class. ARIDE officers learn the Lack of Convergence (LOC) and Modified Romberg Balance (MRB) standardized field sobriety tests. Officers use their ARIDE training in cases where impairment by drugs (cannabis, narcotics, stimulants, etc.) is suspected. Law enforcement training in OVI cases includes administering and interpreting these standardized field sobriety tests. For each test, the officer looks for and records “clues” in the subject’s performance which they are told equates to an increased likelihood of impairment.

Charles M. Rowland II has been certified in the NHTSA Standardized Field Sobriety protocol. He went on to complete the NHTSA Standardized Field Sobriety Test Instructor School, and has gone through the same training as a police officer earning his certification in the A.R.I.D.E. (Advanced Roadside Impaired Driver Enforcement) class. He has further completed training in the Drug Recognition Expert Protocol. When you hire Charlie you are hiring someone who is dedicated to OVI defense.

The Horizontal Gaze Nystagmus (HGN) Test

The horizontal gaze nystagmus test is an eye test approved by the National Highway Traffic Safety Administration (hereinafter NHTSA) as a tool to detect clues of impairment in drivers. The HGN test is one of three psychomotor tests approved as part of the standardized field sobriety testing protocol employed by law enforcement officers throughout the United States and used here in Ohio.

Nystagmus is defined as the oscillation of the eyeball that occurs when there is a disturbance of the vestibular system or the oculomotor control of the eye. During the test, a law enforcement officer is looking for is an involuntary motion. A person is usually unaware of the presence of a nystagmus and cannot control it.

Alcohol is a central nervous system depressant affecting many of the higher as well as lower motor control systems of the body. This results in poor motor coordination, sluggish reflexes, and emotional instability. The part of the nervous system that fine-tunes and controls hand movements and body posture also controls eye movements.

When intoxicated, a person’s nervous system will display a breakdown in the smooth and accurate control of eye movements. This breakdown in the smooth control of eye movement may result in the inability to hold the eyes steady, resulting in a number of observable changes of impaired oculomotor functioning. An eye normally moves smoothly like a marble rolling over a glass plane, whereas an eye with jerk nystagmus moves like a marble rolling across sandpaper.

How Reliable Is the HGN Test?

According to their own manual, the HGN, Horizontal Gaze Nystagmus test is the most reliable of the three standardized field sobriety tests. In addition, the police are trained that the HGN achieves 77% accurate at detecting subjects at or above a .10% blood alcohol concentration. But that is not the whole story.

Officers are not told that everyone (EVERYONE) has nystagmus. The presence of alcohol merely enhances or magnifies this natural effect. In addition, they are instructed that there are 40 different kinds of nystagmus. Yes, everyone – but that is somehow not important to their training. The fact that everyone has it and there are numerous non-impairing causes of nystagmus is deemed irrelevant in the decision to arrest someone. Worse yet, the police officers are given no (NO!) guidance in how to distinguish between the different kinds of nystagmus. And they get no training about what questions to ask that would help them distinguish between an impairment or a natural event. They simply don’t care! If they see it, they will use it against you. Furthermore, courts accept this in probable cause determinations.

The Walk and Turn Test

The Walk & Turn test is a divided attention test that is used as part of the three-test battery of field sobriety tests. The officer will observe your performance on this test, looking for eight (8) clues of impairment. You will be deemed to have failed the test if you present just two (2) of the eight (8) clues. According to NHTSA, the Walk & Turn test is 68% accurate in determining alcohol intoxication above 0.10% BAC (when two or more clues are present).

The law enforcement officer will begin the test by asking you to stand with your right foot in front of your left, touching heel to toe. He or she will then begin to give you a series of instructions and demonstrate how the test is to be conducted. This part of the test is commonly referred to as the Instruction Stage.

The obvious tip here is to listen as best you can to the officer’s instructions. Ask him or her to repeat any instruction that you did not understand as many times as is necessary to be fully informed of what is expected of you. DO NOT BEGIN UNTIL TOLD TO DO SO. This is fundamental and should be one of the easiest parts of the test to comply with.

Non-Standardized Field Sobriety Tests

Ohio has adopted the three-test field sobriety protocol as set forth in the National Highway Traffic Safety Administration (NHTSA) manual for training law enforcement officers. The three tests adopted by NHTSA all survived scientific scrutiny as being indicative of impairment. The tests are: (1) horizontal gaze nystagmus, a test of the subject’s eyes; (2) walk & turn; (3) one-leg-stand. The officer is trained to administer the tests in a standardized fashion and record “clues” of impairment as evidenced by the subject’s performance on the tests.

Often, you will encounter a circumstance where the officer employs a non-standardized field sobriety test. These tests may include nonscientific “techniques”, some of which are described in the NHTSA manual, and can include a finger dexterity test, an alphabet test, a counting test or some other form of confusing coordination test. Some jurisdictions still employ a thoroughly discredited test which requires the subject to tilt their head back and touch the tip of his finger to the tip of his nose.

The Finger Dexterity Test

While not part of the three-test Standardized Field Sobriety Test battery, the Finger Dexterity test is prescribed by officer training as a tool to be used to determine if the officer is justified in continuing the detention of the driver.

The test is not scientifically validated to demonstrate impairment, but Ohio police officers use it anyway. The non-standardized tests are allowed into evidence despite their lack of correlation to impairment. Finger Dexterity test is not a Standard Field Sobriety Test. It has not been recognized by the National Highway Traffic Safety Administration. It is arbitrary and of little value. However, this test is a favorite amongst Ohio law enforcement officers. Try the test yourself. I have administered this test on countless individuals that have consumed zero intoxicants and most fail.

This is how the Finger Dexterity test is conducted:

• The suspect must select which hand they will use for the test;
• Then, the suspect is instructed to touch the thumb of the selected hand and touch each finger tip starting with the index finger and moving toward the pinky finger;
• Next, the suspect must count out loud each time their thumb touches a finger (i.e. “1, 2, 3, 4”);
• As soon as the suspect touches the pinky and counts out loud the number 4 the suspect must immediately execute the test in reverse;
• The suspect’s thumb must touch the pinky finger tip a second time and work backward to the index finger;
• Then, the suspect must count backward, “4, 3, 2, 1”;
• The suspect must perform this routine 3 times.

The contact area of the thumb tip and the finger tip is subjective. Furthermore, the officer is not on camera when conducting this test. No one can question his or her observations. When you couple that with the problem of confirmation bias (the officer is looking for evidence of intoxication), your chance of “passing” this test in the eyes of a police officer investigating you for OVI are slim.

SFST Clues: What Makes You Fail the Field Tests?

Often, at an initial interview, I will have a client tell me that they “aced” the field tests. One of the most common comments is, “I followed his pen perfectly.” Spoiler Alert: if you took the tests it is very likely that the officer observed “SFST clues” of intoxication.

Politely explain to the officer that you are scared and do not know what to do. Ask for an attorney. If the officer says that they just want to see if you are “OK to drive,” repeat: “I am scared and don’t know what to do. I’d like to speak to a lawyer before taking any field tests.” If they threaten to take you to jail unless you take the tests, you are then secure in the knowledge that the officer has already made up his/her mind to arrest and doing the field tests would only give them more evidence to use against you.

Here is a handy guide to what SFST clues an officer is looking for.

Horizontal Gaze Nystagmus Test (6 SFST Clues / 3 each eye)

• Lack of Smooth Pursuit
• Distinct and Sustained Nystagmus
• Onset of Nystagmus prior to 45 Degrees

Walk and Turn (8 SFST Clues)

• Cannot keep balance while listening to the instructions
• Starts too soon
• Stops while walking
• Does not touch heel-to-toe
• Steps off the line
• Uses arms to balance
• Improper turn
• Incorrect number of steps

One Leg Stand (4 SFST Clues)

• The subject sways while balancing
• Uses arms to balance
• Hopping
• Puts foot down

Now you know. The interpretation of these SFST clues is of vital importance. In preparing to defend an OVI case I spent time taking the same course in Standardized Field Sobriety training as the law enforcement officers. In addition, I took the next step and took the SFST Instructor class; meaning that I am qualified to teach law enforcement officers how to administer and evaluate the SFST clues. What’s more, twice every year for fifteen years, I put on a mock trial for the Greene County Peace Officer Training Academy wherein we conduct a mock motion to suppress. This experience is augmented by attending OVI seminars that delve deeply into defending an accused driver. I am honored to have been asked to speak to other lawyers on this topic and do so frequently.

Why Trust Dayton OVI Attorney Charles M. Rowland II

Charles M. Rowland II has established himself as a top OVI attorney in Ohio and the Dayton area and beyond. He lives by the motto, “Work hard, play by the rules, and never quit!” Preparation, dedication and perseverance are his touchstones. He will vigorously fight for you and will genuinely care about the outcome of your case. He wants to make an impact on the system and on every client he represents. He wants to get the most favorable outcome including acquittals, dismissed charges, or advantageous reduced charges.

He has been recognized by his clients and his peers as a top OVI attorney. He has been a “Super Lawyer” since 2013, a Fellow to the Ohio State Bar Foundation, the Nations Top 1%, the National Trial Lawyers Top 100 for Criminal Defense, a Dayton Bar Association Foundation Fellow, and has appeared in Time and Car & Driver Magazine for OVI defense. He is a lecturer on OVI defense to police agencies, attorneys, judges, and students. He frequently appears as an expert in local media. He taught OVI trial practice at the Greene County Peace Officer Training Academy for over fifteen years and has been an adjunct professor at Wright State University in the Honors Department. In 2026, he will teach criminal law in Eastern Europe for the Center for International Legal Studies at the prestigious University of National and World Economy.

Charlie is a member of the Dayton Bar Association, the Dayton Bar Foundation (2022 Foundation Fellow), the Greene County Bar Association (past President), the Clark County Bar Association, the Ohio State Bar Association, the Ohio State Bar Foundation (2005 Foundation Fellow), the American Bar Association, the American Bar Foundation, and a member of Dayton Lodge No. 147 and Beavercreek Lodge No. 788, under the Grand Lodge of Ohio.

“All I ever wanted to do was to be a good attorney. I have been blessed that my hard work has allowed me to achieve everything I have, and I will continue to work hard for my clients and for my profession” – Charles M. Rowland II

Learn More About Ohio OVI Charges & Penalties

Standardized Field Sobriety Tests · Types and Causes of Nystagmus · The Walk and Turn Test · The One-Leg-Stand Test · Non-Standardized Field Sobriety Tests · Chemical Test Refusal · Defenses to an OVI

Frequently Asked Questions