Is the HGN Test Legal in Arizona? 2026

If you’ve been pulled over under suspicion of a DUI, you may have undergone a field sobriety test, including a Horizontal Gaze Nystagmus (HGN) test. This test, along with the walk-and-turn and one-leg stand tests, is one of the sobriety tests approved by the National Highway Traffic Safety Administration (NHTSA). It is routinely used at traffic stops in Arizona by law enforcement officers when they suspect driving under the influence. But is the HGN test legal in Arizona?

The answer is complicated. While the test is legal in that it’s one of the standardized methods officers may use to assess the level of intoxication, it is not a mandatory test. In fact, if you are ever pulled over for a suspected DUI, it is in your interests to politely refuse to comply with the HGN or any other physical field sobriety test and request the counsel of a DUI lawyer if you are arrested.

What Is the HGN Test?

The HGN test is an involuntary jerking of the eyes when looking to the side, a reflexive movement that the subject cannot control, especially when impaired by alcohol or other drugs. The HGN test detects this response when the administering officer instructs the subject to stand still and track a moving object, such as a pen or a finger, from side to side, 12-15 inches in front of the subject’s nose, to test for the involuntary jerking.

Inaccurate Results and Subjectivity With the HGN Test

While the NHTSA intended field sobriety tests to be a helpful tool, these tests are intrinsically flawed. Results for the test rely on the objectivity of the officer administering the test, whether they correctly follow the procedure for the test, and the subject’s ability to follow directions.

If the driver has any physical or neurological conditions, such as multiple sclerosis, vestibular issues affecting balance, or visual acuity issues, such as amblyopia, their ability to perform the HGN test and other field sobriety tests will be compromised, leading to the potential for wrongful DUI charges. These tests are often positive, due to their subjective nature, and these false positives can lead to arrest and conviction, potentially impacting your life for years to come. 

A qualified DUI defense lawyer, when challenging a field sobriety test case, will call into question the validity of the HGN test and surface any concerns around the administration of the test and their client’s ability to perform it. 

You Don’t Have to Perform the HGN

Many drivers do not realize that performing the HGN, or any other physical field sobriety test, is not mandatory in Arizona. While refusing a chemical breathalyzer test could lead to license suspension or other penalties, refusing a field sobriety test is well within your rights, even if you are arrested because you refuse to comply.

If you are ever pulled over and the officer instructs you to perform the HGN or other tests, apart from the chemical test, politely refuse and ask to speak to a lawyer. Our team at Davidson Criminal Defense & DUI Law Firm is available 24/7 to offer legal guidance if you are facing DUI charges. 

Hire a Field Test Sobriety Lawyer

If you’ve already submitted to a field sobriety test, it’s not too late to challenge the results of an HGN or any other test. Ultimately, prosecutors must prove that you were intoxicated beyond a reasonable doubt, and the HGN is only one element of the evidence they must present to the courts. A confident, knowledgeable DUI defense lawyer can develop a strategic defense, using details from your arrest to build a convincing case to reduce or dismiss your charges.

FAQs

Is Arizona Still a Zero-Tolerance State?

Yes, for drivers under the age of 21. Any DUI for an underage driver leads to serious consequences, including a mandatory two-year license suspension. While Arizona has some of the strictest DUI laws in the country, charges can be reduced in some circumstances, which is why it’s crucial to speak to a lawyer who is qualified to defend the rights of those facing a DUI accusation.

Is the HGN 88% Accurate?

Studies evaluating the accuracy of field sobriety tests, including the HGN, vary in their percentage of accuracy. These tests were initially developed in laboratory settings, under closed observation. In the field, the HGN is the most accurate of all three physical field sobriety tests, but even at its highest efficacy, the results vary according to the skill of the officer administering the test and the subjective interpretation of the results. 

Is the HGN Test Admissible in Court?

Yes, although it can always be challenged by the defense team. Prosecutors can use the results of any physical field sobriety test as evidence, but the soundness of the evidence can be called into question, especially if other forms of evidence, such as the chemical breathalyzer or blood test, do not support the results of the field sobriety test. 

How Much Does It Cost to Hire a DUI Lawyer to Defend My Case?

Attorney fees vary according to the experience level of the lawyer, their hourly rates, if they charge a retainer fee, and the complexity of the case. Location can also impact costs. The fee for representation is always discussed during the initial consultation, and potential clients are under no obligation to retain an attorney after the initial consultation.

We Advocate for Your Right to a Fair DUI Trial

Sometimes, a night out with friends can result in life-changing consequences, given Arizona’s strict DUI laws. DUI arrests are not uncommon in Maricopa County, with a reported 447 DUI arrests made in 2024 alone. Statewide, that number rose to over 208,000 DUI arrests. 

At Davidson Criminal Defense & DUI Law Firm, we know how stressful it can be to face the possibility of a DUI conviction. With over 20 years of experience in the Scottsdale area, we are qualified to represent your case at all Municipal, Superior, and Justice Courts.We’re here to listen with compassion and offer sound legal advice to Maricopa County residents facing a DUI. If you’ve wondered, “Is the HGN test legal in Arizona?” contact us today to schedule your free initial consultation and learn more.