Is a Radar Detector Legal in the US?

Conditional

A radar detector is legal for passenger cars in almost all of the US. The exceptions are Virginia, which bans them, and Washington, D.C.; federal rules also prohibit them in large commercial vehicles, and they are banned on military bases.

Why?

For an ordinary passenger vehicle, radar detectors are legal to own and use in every state except Virginia, where possession and use in a car are prohibited. Washington, D.C. also bans them. Everywhere else, they are a legal driving aid.

Two federal-style limits apply on top of that: radar detectors are banned in commercial vehicles over 10,000 pounds under Federal Motor Carrier Safety rules, and they are prohibited on most US military installations regardless of the state.

A radar detector should not be confused with a laser jammer, which actively interferes and is banned in a number of states. A detector only receives, which is why it is legal for cars nearly everywhere. If you drive through or live in Virginia or D.C., though, it is not.

What decides if it's legal

Radar detectors are legal in passenger cars in every state except Virginia.
They are also banned in Washington, D.C.
Federal rules ban them in commercial vehicles over 10,000 lbs.
They are prohibited on most military bases.

Does it depend on your state?

Yes, on your state and vehicle type. Legal in passenger cars everywhere except Virginia and D.C.; banned in heavy commercial vehicles by federal rule and on military bases.

Related legality guides

Find your car in the garage

Sources

This page is general guidance, not legal advice, on the rules in the US for radar detector. The detail varies by exact vehicle and changes over time - confirm with your insurer and the EPA, NHTSA and your state DMV before modifying.