Are Radar Detectors Legal? State-by-State Guide

Radar detectors are legal for use in passenger vehicles in 49 out of 50 states, plus the District of Columbia has its own rules. The only state that bans radar detectors outright is Virginia. In all other states, you are generally free to use a radar detector in your personal, non-commercial vehicle. However, keep in mind that radar detectors are banned in all commercial vehicles over 10,000 pounds gross weight by federal law (enforced by the FMCSA). Military bases prohibit radar detectors on their property. Some states restrict how devices can be mounted on the windshield.

Virginia is the only state in the country that bans the use of radar detectors in all vehicles. Under Virginia Code section 46.2-1079, it is illegal to use, possess, or sell radar detectors in the state. Law enforcement officers in Virginia use "radar detector detectors" (RDDs) to identify vehicles with active detectors. The penalty for using a radar detector in Virginia is a fine (typically around $40 to $250) and confiscation of the device. If you are driving through Virginia, make sure to turn off and store your radar detector before entering the state.

While not a state, Washington DC also has restrictions on radar detectors. The District bans the use of radar detectors. Additionally, all US military installations prohibit the use of radar detectors on their property, regardless of the state the base is located in. Driving onto a military base with an active radar detector can result in confiscation of the device and potential disciplinary action.

It is important to distinguish between radar detectors and radar jammers. Radar detectors passively receive radar signals and alert you. These are legal in most states. Radar jammers actively transmit signals to interfere with police radar and are illegal under federal law (47 USC section 333). Using a radar jammer is a federal offense that can result in fines up to $100,000 and imprisonment. LiDAR jammers (which interfere with laser speed detection) are illegal in many states but not explicitly prohibited by federal law. Never use a radar jammer. The penalties are severe and it is a federal crime.

Traditional radar detectors have limited effectiveness against modern speed cameras. Many speed cameras use LiDAR (laser) rather than radar, which gives very little warning time even with a detector. Some fixed speed cameras are always on and may use sensors in the road rather than radar. Advanced radar detectors can detect some camera systems, but the warning time may not be sufficient to slow down. GPS-enabled detectors with camera databases (like those from Valentine, Escort, or Uniden) can alert you to known fixed camera locations, which may be more useful than passive radar detection for avoiding camera tickets.