Have you ever wondered, “Are radar detectors illegal in California? What about Iowa?” Radar detectors can prove invaluable at keeping you alert and safe while on the road, but not all states allow you to have one mounted on your dash. Let’s go over what states radar detectors are illegal in.
What Are Radar Detectors?
A radar detector is a tool that drivers use to detect when they’re being monitored by a police speedometer. Typical models provide audio and visual warning that your vehicle is in the range of one of these speedometers. This can be handy as a reminder to double-check your speed, especially because it might be hard to notice that you’re going fast.
State Radar Detector Laws
It’s easy to see how these tools can be abused and why radar detectors are illegal in some states. Here are the states that declared radar detectors are illegal and those that allow them. When it comes to radar detector laws, there are also different rules for private and commercial vehicles.
A radar detector is a tool that drivers use to detect when they’re being monitored by a police speedometer.
Private Vehicles
Iowa
The laws in Iowa can be a little confusing. At first glance, it seems that only “speed detector jamming devices” are deemed illegal, but the law also “includes but is not limited to devices commonly known as radar speed meters or laser speed meters.” If your device interferes with, disrupts, or scrambles the police radar gun, then you’re liable to face charges.
Minnesota and California
Minnesota and California both allow private vehicle owners to use radar detectors, but they don’t allow you to mount them on your windshield. These states want to prevent drivers from obstructing their view of the road.
Virginia
Virginia is the strictest state when it comes to radar detectors. You’re not allowed to use one at all while on the state’s roads, and selling them is also illegal here. While carrying a radar detector in the vehicle without a power source is permitted, the driver and occupants cannot have access to it in any way, rendering it unusable.
Other States
For all other states, radar detectors are legal for private vehicles to use. Keep in mind that some radar detectors receive and boost the police radar signal, which buys you time to slow down. These detectors are more like radar jammers, and there might be different laws for them.
Commercial Vehicles
Commercial vehicles, especially large trucks, can pose a significant risk to the public when they speed. Because of this, all states have a ban on radar detectors in commercial vehicles that weigh over 10,000 lbs. Illinois, Iowa, Minnesota, New Jersey, New York, Virginia, and Washington D.C. extend this to all commercial vehicles no matter their weight. Eighteen-wheelers used for interstate commerce are forbidden from using radar detectors in the cab even if they’re switched off.
Police speedometers, also known as radar guns, are able to measure your car’s speed using radio waves.
How Do Radar Detectors Work?
Radar detectors function as receivers. Police speedometers, also known as radar guns, are able to measure your speed using radio waves. Radio detectors are tuned to pick up these waves, much like your radio is tuned to pick up your favorite station. The horn or waveguide is the part of the radar detector that receives the signal.
Most radar detectors in North America are tuned to the X-band, K-band, and Ka-band signals, which are what most radar guns in the States use. Because radar guns transmit their frequency for miles, a good radar detector will be able to warn you long before your vehicle gets targeted for a speed test.
Once the radar detector senses the presence of the offending radio waves, it feeds the information to a microprocessor. The microprocessor identifies the signal and alerts you immediately.
Types of Radar Detector
If you’re looking to buy a radar detector, there are two types to look at:
Dash or Window-Mounted Radar Detectors
These are the more common radar detectors. They attach to your dashboard or windshield using suction cup mounts and can be easily moved or transferred. Because they’re so simple to install and remove, they’re very handy if you have multiple vehicles. In addition, if you happen to be driving through a state where radar detectors are illegal, you can simply remove your unit and store it, unpowered, in the trunk for safe keeping.
Custom-Installed or Remote Radar Detectors
These radar detectors are much less common since they require a good amount of work to use. Unlike the typical window-mounted radar detector, which has all of its parts in a single unit, custom radar detectors have their parts integrated into the vehicle itself. This provides a much sleeker look overall since it’ll appear to be part of the vehicle’s system.
Lisa Conant grew up in Canada around a solid contingency of gear heads and DIY motor enthusiasts. She is an eclectic writer with a varied repertoire in the automotive industry, including research pieces with a focus on daily drivers and recreational vehicles. Lisa has written for Car Bibles and The Drive.
The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.
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