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Radar detector laws by state

Are radar detectors legal in California?

Legal in passenger cars

Detectors are legal in California, but the windshield rule, the jammer ban and the speed-trap law decide the details.

By I Go Cars ·

California's answer

Yes. Radar detectors are legal in private passenger vehicles in California; no provision of the Vehicle Code prohibits owning or using one. The practical limit is where the unit goes, because Vehicle Code § 26708 restricts objects on the windshield and does not list radar detectors among its exceptions.

Jammers are a different matter. Section 28150 bans equipping a vehicle with any device built to jam or scramble police radar or laser, and it reaches possession and sale as well as use. A passive detector is not named in it.

What makes California distinctive is its rules for the officer holding the radar gun. The speed-trap statute can make an officer's radar evidence inadmissible when the posted limit is not backed by a current engineering and traffic survey, and California has opened a narrow door to speed cameras through a pilot program that runs to 2032. Both are covered below as of October 2026.

Windshield mounting under Vehicle Code § 26708

Section 26708(a)(1) bars driving with any object or material placed, displayed, installed, affixed or applied on the windshield or the side or rear windows. Subsection (a)(2) separately bars any object inside the vehicle that obstructs or reduces the driver's clear view through those windows. The exceptions in subsection (b) are unusually detailed:

  • signs, stickers or other materials in a 7-inch square in the lower corner of the windshield farthest from the driver, or a 5-inch square in the lower corner nearest the driver ((b)(3));
  • a toll or California Highway Patrol communication device in a 5-inch square at the center top of the windshield ((b)(11));
  • a portable GPS unit in those same lower-corner squares ((b)(12));
  • a video event recorder ((b)(13)).

No exception names a radar detector. Whether a detector could qualify as “other materials” under (b)(3) is not settled by the text, and no source resolving it was found. The location the statute leaves open is the dashboard, provided the unit sits below the driver's line of sight so that (a)(2) is not triggered.

Section 26708 states no penalty of its own, so § 40000.1 makes a violation an infraction. The base fine is set outside the Vehicle Code and was not researched for this page.

Jammers: Section 28150 reaches possession and sale

California's jammer statute is broader than most. Subsection (a) provides that no vehicle may be equipped with a device “designed for, or ... capable of, jamming, scrambling, neutralizing, disabling, or otherwise interfering with” radar, laser or any other electronic device police use to measure speed. Subsection (b) adds that no person may use, buy, possess, manufacture, sell or otherwise distribute one. A violation is an infraction under (c); possessing four or more devices is a misdemeanor under (d). Subsection (e) lets the holder of a valid federal license transport devices if the license is carried in the vehicle.

The phrase “radar, laser, or any other electronic device” matters. Federal jammer enforcement belongs to the FCC, whose authority covers radio frequencies; it treats any transmitter that interferes with police radar as prohibited, but laser jammers emit light and fall outside that radio jurisdiction. California's statute covers laser on its own terms.

The speed-trap law and the engineering and traffic survey

Vehicle Code § 40801 provides that no peace officer “shall use a speed trap” in making a speed arrest or gathering evidence of speed. Section 40802(a) defines two kinds of speed trap. The first is a measured section of road with marked boundaries, used to time a vehicle over a known distance. The second is the one that matters to radar: a stretch with a prima facie speed limit (a limit presumed safe unless shown otherwise) that is “not justified by an engineering and traffic survey conducted within five years prior to the date of the alleged violation,” where the speed is measured by radar or another electronic device.

The second definition excludes local streets and roads, school zones, senior zones, business activity districts and limits adopted under §§ 22358.7 or 22358.8. A “local street or road” under § 40802(b) is one classified local on the California Road System Maps, or one that mainly serves abutting residences, is no more than 40 feet wide, runs no more than half a mile uninterrupted and has no more than one lane each way.

Section 40802(c) lengthens the survey window when the officer and the equipment meet stated standards. The officer must have completed a POST-certified radar course of at least 24 hours (POST is the state's Commission on Peace Officer Standards and Training), plus at least two more hours for laser; the device must meet NHTSA's minimal operational standards and have been calibrated by an independent certified facility within three years; and the prosecution must prove the training, the survey, that the officer verified the device before citing and, except for maximum-speed citations under §§ 22349, 22356 or 22406, that the speed was unsafe for conditions. The survey may then be seven years old, or up to 14 years if a registered engineer finds no significant change. The text as updated January 1, 2026 contains no ten-year window, despite frequent claims otherwise.

The consequences are procedural. Under § 40803 the prosecution must show, as part of its prima facie case, that radar evidence did not come from a speed trap. Section 40804 makes an officer who relied on a speed trap “incompetent as a witness,” and also disqualifies certain traffic testimony from an officer not in a distinctive uniform or a vehicle painted to the CHP commissioner's specification. Section 40805 leaves a court “without jurisdiction to render a judgment of conviction” if it admits such evidence. No other state covered on this site imposes a comparable burden on the prosecution.

How the CHP measures speed, including from the air

The California Highway Patrol's own policy mirrors the statute. Highway Patrol Manual 70.6, Chapter 7 (revised May 2011), states that “the Legislature has made the use of speed traps unlawful,” commits the department to visible enforcement, requires 24 hours of academy training and 30 hours of field training before an officer uses radar for enforcement, and requires each device to be certified by an independent laboratory and tested at the start and end of every shift.

The same chapter describes aircraft enforcement. Because “airspeed is not an accurate representation of ground speed,” the officer in the aircraft times the plane between pavement markings with a stopwatch while pacing the suspect vehicle, then converts the time to miles per hour from a chart (HPM 70.6, Chapter 7). The CHP Office of Air Operations lists 12 helicopters and 13 airplanes and names traffic enforcement among the airplanes' missions. Current practice beyond the 2011 manual was not confirmed.

Cameras: red-light systems statewide, speed cameras only in pilots

Red-light cameras are authorized under § 21455.5, which requires signs within 200 feet, a 30-day warning-notice period and a public announcement at least 30 days before enforcement, and allows only a governmental agency working with law enforcement to operate a system. Section 21455.6(c) adds that the authority “does not authorize the use of photo radar for speed enforcement purposes.”

AB 645 (2023) carved out the exception. Vehicle Code §§ 22425 to 22431 create the Speed Safety System Pilot Program for six jurisdictions: Los Angeles, San Jose, Oakland, Glendale, Long Beach and the City and County of San Francisco (Veh. Code § 22425). Cameras may run on designated safety corridors, on streets with repeated speed-contest incidents and in school zones, capped by population from 125 systems in the largest city down to nine in the smallest.

Under § 22426 a pilot citation is a civil penalty with no license point and no suspension: $50 for 11 to 15 mph over, $100 for 16 to 25, $200 for 26 or more and $500 at 100 mph or above. Section 22429 cuts the penalty by 80 percent for indigent drivers and by 50 percent up to 250 percent of the federal poverty level. The pilot is repealed on January 1, 2032. Separately, SB 1297 (2024) added § 22435, which allows Malibu up to five systems on the Pacific Coast Highway, bringing the total to the seven jurisdictions GHSA counts. Which pilot cities were issuing citations as of October 2026 was not researched.

Commercial vehicles and common mistakes

For trucks, California adds nothing to the federal rule, and none is needed: 49 CFR 392.71 already bars a commercial driver from using a detector or driving a commercial motor vehicle carrying one, with the line drawn at 10,001 pounds for interstate operation under 49 CFR 390.5. No California-specific commercial-vehicle detector statute was identified.

  • “Detectors are illegal in California.” They are not; the windshield rule is the real constraint.
  • “Any radar ticket without a fresh survey is void.” Local streets, school and senior zones and business districts are excluded, and trained officers with calibrated equipment get a seven- or 14-year window.
  • “California bans all photo radar.” It does, except in the AB 645 pilot cities and on Malibu's stretch of the Pacific Coast Highway.
  • “Camera tickets add points.” Pilot citations carry no point and no suspension.

This is a summary of the Vehicle Code as of October 2026, not legal advice; the official text on the California Legislative Information site governs.

Frequently asked questions

Are radar detectors legal in California?

Yes. No California statute bans radar detectors in passenger vehicles. The restriction that matters is Vehicle Code § 26708, which bars objects on the windshield except listed items, and radar detectors are not on that list. A windshield-mounted detector can therefore be cited as an infraction, while a dash-mounted unit below the line of sight is not addressed by the section.

Can you mount a radar detector on the windshield in California?

Not under any express exception. Section 26708 allows signs or stickers in a 7-inch or 5-inch lower corner square, toll devices at the top center, portable GPS units and video event recorders, but it never names radar detectors. Whether a detector counts as “other materials” in the corner squares is unsettled, so the dashboard is the location the text leaves open.

Are laser jammers legal in California?

No. Vehicle Code § 28150 bans equipping a vehicle with, using, buying, possessing, manufacturing or selling any device that jams or interferes with radar, laser or other police speed devices. A violation is an infraction, and possessing four or more devices is a misdemeanor. Federal license holders may transport devices with the license in the vehicle.

What is a speed trap in California?

It is either a timed, measured section of road or radar and laser enforcement of a prima facie limit not supported by a current engineering and traffic survey, as defined in Vehicle Code § 40802. The survey window is five years, or seven to 14 years with trained officers and calibrated devices. Evidence from a speed trap is inadmissible under § 40803.

Does California have speed cameras?

Only in pilot programs as of October 2026. Vehicle Code § 22425 authorizes speed cameras in Los Angeles, San Jose, Oakland, Glendale, Long Beach and San Francisco, and § 22435 allows up to five on Malibu's Pacific Coast Highway. The main pilot is repealed on January 1, 2032. Elsewhere, § 21455.6(c) bars photo radar.

How much is a California speed camera ticket?

It is $50 for 11 to 15 mph over the limit, $100 for 16 to 25 over, $200 for 26 or more over and $500 at 100 mph or above, under Vehicle Code § 22426. The penalty is civil, with no license point and no suspension, and § 22429 reduces it by 80 percent for indigent drivers.

Does CHP use airplanes to catch speeders?

Yes. CHP policy in Highway Patrol Manual 70.6, Chapter 7, describes aircraft enforcement in which the officer times the plane between pavement markings with a stopwatch while pacing a vehicle, then converts the time to speed from a chart. The CHP Office of Air Operations lists traffic enforcement among its airplanes' missions.

Sources

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