DUI Tests in Utah: What You Must Take and What You Can Refuse

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When you are pulled over and an officer suspects you have been drinking, you will be asked to do several things. Some of them you can decline with no direct penalty. One of them you cannot refuse without separate consequences for your license. Most people do not know the difference in the moment, which is exactly why officers ask. Here is how the tests actually work in Utah.

There Are Two Different Kinds of Tests

The single most important thing to understand is that DUI testing comes in two stages, and the rules are completely different for each. The first stage happens at the roadside, before any arrest. These are investigative tools the officer uses to build probable cause, and they are generally voluntary. The second stage happens after arrest. This is the official chemical test, and it is governed by Utah's implied consent law. Confusing the two is what gets people into trouble.

Field Sobriety Tests Are Voluntary

The roadside coordination exercises, such as the walk-and-turn, the one-leg stand, and the eye-tracking test known as horizontal gaze nystagmus, are standardized field sobriety tests. In Utah, these are voluntary. You are not legally required to perform them, and politely declining is not itself a crime and does not carry an automatic license penalty.

It is worth understanding why these tests favor the officer. They are graded entirely on the officer's observation, they are difficult for many sober people to perform on the shoulder of a road at night, and the results become evidence the prosecution uses against you. Declining them deprives the officer of that evidence. It will not necessarily prevent an arrest, because the officer can still rely on other observations, but you are under no obligation to help build the case.

The Roadside Breath Test Is Also Voluntary

At the roadside, an officer may offer a small handheld device called a portable or preliminary breath test. This is not the official test. Its result is used to help establish probable cause to arrest, and it is generally not admissible in court as proof of your blood alcohol level. Like the field sobriety tests, the roadside portable breath test is voluntary, and you can decline it.

The Chemical Test After Arrest Is Different

Once you are lawfully arrested for DUI, Utah's implied consent law applies. Under Utah Code Section 41-6a-520, anyone who operates a vehicle in Utah is deemed to have already consented to a chemical test of breath, blood, urine, or oral fluids to determine alcohol or drug content. The officer chooses the test. Before the test, the officer must warn you that refusing can result in revocation of your driver license and other driving restrictions.

This is the test you cannot refuse without separate consequences. A refusal triggers an administrative action against your driver license through the Driver License Division that is separate from the criminal DUI case, and the refusal itself can be used against you as evidence in the criminal case. In other words, refusing the post-arrest chemical test does not make the DUI go away. It adds a second problem on top of it.

Blood Tests and the Warrant Requirement

Blood tests have an added layer of constitutional protection. In Birchfield v. North Dakota, 579 U.S. 438 (2016), the United States Supreme Court held that police generally need a warrant to take a blood sample, and that a State cannot make it a crime to refuse a warrantless blood draw. A breath test, by contrast, can be required as a search incident to a lawful DUI arrest without a warrant.

What this means in practice is nuanced. If an officer wants your blood, they typically need a warrant, and in Utah officers can often obtain an electronic warrant quickly. Once a valid warrant exists, you cannot lawfully refuse the draw. And even where Birchfield limits criminal penalties for refusing a warrantless blood test, refusing the chemical test can still carry administrative license consequences under implied consent. This is precisely the kind of situation where the specific facts matter and where you want a lawyer, not a guess.

So Should You Refuse?

There is no honest one-size-fits-all answer, and anyone who gives you a blanket rule is overselling. Declining the voluntary roadside tests, the field sobriety exercises and the handheld breath device, generally avoids handing the officer extra evidence and carries no automatic license penalty. The post-arrest chemical test is a harder call, because refusing it has its own license and evidentiary consequences that can be worse than the test result would have been. The right choice depends on the facts, your driving history, and what is actually happening at the stop.

What is always true: stay calm, stay polite, do not argue or resist, and do not try to talk your way out of it. Then call a lawyer as soon as you can, because the clock on your license starts at the arrest.

This article is attorney advertising and is for general informational purposes only. It does not constitute legal advice and does not create an attorney-client relationship. DUI law is fact-specific and changes, and the right course of action depends on your circumstances. Contact an attorney to discuss your situation.