Are Radar Detectors Legal in Texas? Cars, Trucks, Windshields and Jammers

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

Texas is a big state with long, fast highways, and a radar detector is a popular gadget for drivers on I-10, I-35 and the open stretches of West Texas. Texas law treats detectors and jammers very differently, though, and its windshield rule is stricter in wording than many states'. This page covers Texas; for other states, see our guide to where radar detectors are legal.

Short answer: yes, radar detectors are legal in Texas in private passenger vehicles. Texas has no statute banning them. They are not allowed in commercial motor vehicles, because Texas adopts the federal rule that bans them. Radar and laser jammers are illegal under Texas Transportation Code § 547.616. Keep the detector off the part of the windshield you look through.

Private cars: legal in Texas

Texas has no law that bans a radar detector in a private vehicle. That covers cars, SUVs, minivans and pickups you drive for personal use, and it applies to Texans and visitors alike.

A radar detector is a receiver. It listens for the radio signals that police radar guns send out (and, on many models, the light pulses from laser speed guns) and warns you. It doesn't transmit anything at police equipment, which is why Texas's interference statute doesn't reach it.

Two things a detector does not do:

• It doesn't change the speed limit. Texas officers can still pace you or use other methods, and a speeding ticket is the same whether or not you got a warning.
• It doesn't help in school or work zones. We found no Texas law banning detectors in those zones, but the lower limits and closer enforcement still apply.

Radar and laser jammers: banned under § 547.616

This is where Texas is stricter than many states. Since September 1, 2011, Transportation Code § 547.616 has banned "radar interference devices".

• What counts. The statute defines a radar interference device as a device, mechanism, instrument or equipment that is "designed, manufactured, used, or intended to be used to interfere with, scramble, disrupt, or otherwise cause to malfunction a radar or laser device used to measure the speed of a motor vehicle" by Texas law enforcement, including a "radar jamming device," "jammer," "scrambler," or "diffuser." Laser jammers are covered by name.
• What doesn't count. The definition excludes "a ham radio, band radio, or similar electronic device." A passive radar detector isn't designed to interfere with anything, so it falls outside the ban.
• What's prohibited. Using, attempting to use, installing or operating a jammer in a vehicle you drive (subsection b), and buying, selling or offering one for sale for that use (subsection c).
• The penalty. A violation is a Class C misdemeanor. Under Texas Penal Code § 12.23, that means a fine of up to $500.

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).

Many detectors are sold as "combo" units with laser shifters or jammers built in. If you shop online, read the spec sheet: a unit that only receives is fine in a Texas car; one that transmits back at police lidar is not.

Commercial trucks and buses: not allowed

The federal rule in 49 CFR 392.71 bans radar detectors in commercial motor vehicles (CMVs) in interstate commerce. Texas law lets the Department of Public Safety adopt the federal safety rules by reference (Transportation Code § 644.051), and DPS has done so in 37 Texas Administrative Code § 4.11, which incorporates 49 CFR Parts 390 to 393 and others.

That Texas rule also reaches many trucks that never leave the state. Under § 4.11(c)(1), the federal rules apply to:

• vehicles with an actual gross weight or weight rating over 26,000 pounds operating intrastate,
• farm vehicles of 48,000 pounds or more operating intrastate,
• vehicles designed or used to carry more than 15 passengers, including the driver,
• vehicles carrying hazardous materials that require a placard.

For interstate trips, the federal definition in 49 CFR 390.5 is broader: a CMV generally includes a vehicle rated at 10,001 pounds or more, among others. Three points make the federal rule stricter than many drivers expect:

• Possession is enough. An unplugged detector in the door pocket of a CMV still breaks the rule.
• The employer is responsible too. Under § 392.71(b), a motor carrier may not "require or permit" a driver to violate it.
• Laser counts. The federal definition of "radar detector" covers devices that detect police radio microwaves, laser beams or "any other future speed measurement technology."

If you drive a big rig, a bus or a placarded load, keep the detector in your personal car.

Windshield mounting under § 547.613

Texas's windshield statute is short and strict. It makes it an offense to drive with an object or material on the windshield or side or rear windows that "obstructs or reduces the operator's clear view." Unlike Florida's rule, which targets material that "materially" obstructs the view, there's no such qualifier here, and the statute doesn't carve out an exception for radar detectors, GPS units or dash cams.

Some details worth knowing:

• Out-of-state vehicles are exempt. Section 547.613(b)(12) says subsection (a) doesn't apply to "a motor vehicle that is not registered in this state." A visitor's windshield mount isn't covered by this section, though general safety rules still apply.
• Commercial motor vehicles are exempt from subsection (a) under (b)(16), but detectors are banned in CMVs anyway.
• The penalty. Section 547.613 doesn't set its own fine for drivers, so the general Transportation Code penalty applies: a fine of $1 to $200 (§ 542.401).

Practical ways to stay on the right side of it:

• Use a dash mount with a non-slip pad, or a rearview-mirror mount (rearview mirrors are exempt under (b)(4)).
• Keep the unit low and out of your sight line, not in the middle of the glass.
• Run the power cord along the trim, not across the windshield.

Thinking about tint too? See our guide to window tint laws in Texas, which covers the same section.

The FCC rule behind modern detectors

The Federal Communications Commission 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. Its 2002 order also noted that manufacturers had raised oscillator frequencies partly to make detectors harder for police to detect.

For you as a buyer: stick with an FCC-certified detector sold through normal US channels. It keeps you clear of the federal equipment rules, but it doesn't make a jammer legal in Texas.

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. Texas has several large installations, so check the base's traffic code before driving on with a detector.
• Washington, D.C. The District bans selling detectors and using or possessing one in a car (18 DCMR § 736).

Texas compared with other states

Road-tripping? See our guides for Florida, Illinois and Virginia.

Practical do's and don'ts in Texas

• Do keep detectors to personal vehicles.
• Do check whether a "combo" unit transmits. If it does, it's a jammer under Texas law.
• Do check your employer's policy for any work vehicle; many fleets ban detectors even in light vehicles.
• Don't leave a detector in a commercial vehicle "just in case". Possession alone breaks the federal rule.
• Don't stick the detector where it blocks your view through the windshield.
• Don't treat the detector as permission to speed.

Sources

• Texas Transportation Code § 547.613 (restrictions on windows) and § 547.616 (radar interference devices): Texas Legislature
• Texas Transportation Code § 542.401 (general penalty): Texas Legislature
• Texas Transportation Code § 644.051 (authority to adopt commercial vehicle rules): Texas Legislature
• Texas Penal Code § 12.23 (Class C misdemeanor): Texas Legislature
• 37 Texas Administrative Code § 4.11 (adoption of federal motor carrier safety 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