Are Radar Detectors Legal in Utah? Detectors, Jammers, Mounts and Trucks

Last reviewed: October 18, 2026. This article is general information, not legal advice. Utah statutes change, so check the current Utah Code or ask a Utah attorney if you get a citation.

Utah has long, fast interstates, from I-15 along the Wasatch Front to I-80 across the salt flats, and plenty of drivers there use a radar detector. Utah leaves detectors alone in ordinary cars, but it has its own statute banning radar and laser jammers, and a windshield law with specific measurements. This page covers Utah; for other states, see our guide to where radar detectors are legal.

Short answer: yes, radar detectors are legal in Utah in private passenger vehicles. Utah has no statute banning them. Radar and laser jammers are illegal under Utah Code 41-6a-609, and detectors are banned in commercial motor vehicles because Utah adopts the federal rule. Mount a detector so it doesn't materially obstruct your view.

Private cars: legal in Utah

Utah has no law that bans a radar detector in a private vehicle. That covers cars, SUVs, minivans and pickups you drive for personal use, for residents and visitors alike.

A radar detector is a receiver. It listens for police radar signals (and, on many models, laser pulses) and warns you. Utah's jammer statute is aimed at devices "designed or intended to interfere with" police radar or laser, and a passive detector doesn't interfere with anything.

A detector doesn't change the speed limit. Officers can still pace you or use other methods, and a ticket is the same with or without a warning.

Radar and laser jammers: banned under 41-6a-609

Utah is one of the states that bans laser jammers by name. Here's how the statute works:

• The definition (subsection 1). A "radar jamming device" is any instrument or mechanism designed or intended to interfere with police radar or any laser used to measure speed.
• Having one in the vehicle (2)(a). You may not drive on a highway with a jamming device in the vehicle. That's broader than "using" one.
• Using one (2)(b). You may not knowingly use a jamming device to interfere with police radar signals or lasers.
• The defense (subsection 3). "It is an affirmative defense to a charge under Subsection (2)(a) that the radar jamming device was in an inoperative condition or could not be readily used at the time of the arrest or citation." That helps a driver with a unit boxed in the trunk, but it's a defense you raise after the citation, not a safe harbor that prevents one.
• Police exception (subsection 4). The section doesn't apply to law enforcement acting officially.
• The penalty (subsection 5). A violation is an infraction. Under Utah Code 76-3-301, the fine for an infraction can be up to $750.

Radar jammers are also illegal under federal law, which says no person shall "willfully or maliciously interfere with or cause interference to any radio communications of any station licensed or authorized by or under this chapter or operated by the United States Government" (47 U.S.C. § 333).

Watch out for "combo" units sold online that pair a detector with a laser shifter. If it transmits back at police lidar, it's a jamming device under Utah law.

Windshield mounting under 41-6a-1635

Utah's windshield statute is mostly known for its tint limits, but it also controls what you can put on the glass. Three parts matter for a detector:

• Mounted objects (2)(a). You may not drive with an object or device "hanging or mounted in a manner that materially obstructs the operator's view." This is the main rule for a detector, whether it sits on the glass, the dash or the mirror.
• Nontransparent material (1)(d). You may not drive with "any sign, poster, or other nontransparent material on the windshield or side windows", except a certificate required by law or the vehicle identification number.
• Where nontransparent material is allowed (3). Along the top edge of the windshield if it doesn't extend more than four inches down or below the AS-1 line, whichever is lowest; and in the lower left-hand corner, if it doesn't extend more than three inches to the right of the left edge or more than four inches above the bottom edge.

Notice that Utah's lower-corner allowance is on the left, the driver's side, and it's small. Most detectors won't fit in a 3-by-4-inch area. Practical options:

• Use a dash mount or a rearview-mirror mount, kept low and out of your sight line.
• If you use the glass, keep the unit near the top edge, within four inches and above the AS-1 line.
• Run the cord along the trim, not across the windshield.

A violation of 41-6a-1635 is an infraction (subsection 9).

Commercial trucks and buses: not allowed

The federal rule in 49 CFR 392.71 bans radar detectors in commercial motor vehicles: "No driver shall use a radar detector in a commercial motor vehicle, or operate a commercial motor vehicle that is equipped with or contains any radar detector."

Utah adopts that rule. Utah Administrative Code R909-1-3 incorporates the federal motor carrier safety regulations, including 49 CFR Parts 387 through 399 (which contains Part 392), as amended through June 22, 2023. The rule applies to motor carriers as defined in 49 CFR 390.5 and to intrastate commercial motor carriers under Utah Code 72-9-102, except for passenger vehicles designed to carry 12 or fewer passengers (including the driver) with a weight rating under 13,000 pounds.

Three points make the federal rule stricter than many drivers expect:

• Possession is enough. A CMV that "contains" a detector breaks the rule, even if it's unplugged.
• The employer is responsible too. Under § 392.71(b), a motor carrier may not "require or permit" a violation.
• The definitions are broad. Under 49 CFR 390.5, a CMV generally includes a vehicle rated at 10,001 pounds or more used in interstate commerce, certain passenger vehicles and placarded hazmat vehicles. A "radar detector" includes devices that detect police laser and "any other future speed measurement technology."

The FCC rule behind modern detectors

The FCC regulates radar detectors as "unintentional radiators" under Part 15. Since 2002, 47 CFR § 15.109(h) has required that "Radar detectors shall comply with the emission limits in paragraph (a) of this section over the frequency range of 11.7-12.2 GHz." The FCC adopted the rule after finding that some detectors leaked strong signals into the band used by small satellite (VSAT) terminals. Buy an FCC-certified detector; it keeps you within federal rules, but it doesn't make a jammer legal in Utah.

Military bases and Washington, D.C.

• Military bases. Installations set their own traffic rules. Federal rules for Army installations (32 CFR § 634.25) note that Defense Department policy delegates authority to installation commanders to set additional traffic rules, and radar detectors are widely reported to be banned on bases. We could not open a single federal rule that bans them on every base. If you work at or visit a Utah installation, check its traffic code first.
• Washington, D.C. The District bans selling detectors and using or possessing one in a car (18 DCMR § 736).

Utah compared with other states

For comparison, see our guides for Illinois, which also bans laser jammers but has a storage exception, and Virginia, which bans detectors outright. Riding in Utah? Our guide to lane filtering in Utah covers another Utah-specific traffic rule.

Practical do's and don'ts in Utah

• Do keep detectors to personal vehicles.
• Do check whether a "combo" unit transmits. If it does, leave it at home.
• Do mount the detector on the dash, mirror or top edge of the windshield.
• Don't drive with a jammer in the vehicle, even switched off.
• Don't leave a detector in a commercial vehicle "just in case".
• Don't treat the detector as permission to speed.

Sources

• Utah Code § 41-6a-609 (radar jamming devices): Utah Legislature
• Utah Code § 41-6a-1635 (windshields and windows; obstructions): Utah Legislature
• Utah Code § 76-3-301 (fines of individuals): Utah Legislature
• Utah Admin. Code R909-1-3 (adoption of federal regulations): Cornell LII
• 49 CFR § 392.71 (radar detectors in commercial motor vehicles): Cornell LII
• 49 CFR § 390.5 (definitions of commercial motor vehicle and radar detector): Cornell LII
• 47 U.S.C. § 333 (willful or malicious interference): Cornell LII
• 47 CFR § 15.109 (radiated emission limits, including radar detectors): eCFR
• FCC, Radar Detectors final rule, 67 FR 48993 (July 29, 2002): GovInfo
• 32 CFR § 634.25 (installation traffic codes): Cornell LII
• Virginia Code § 46.2-1079: Virginia Law
• District of Columbia Municipal Regulations, 18 DCMR § 736 (Radar Detectors and Jammers): DC Regulations