As with any piece of equipment in the United States, there's a big difference between using a radar detector privately and commercially. Commercial operation of a device has a greater impact on the public and far more regulation is required. Any vehicle that is used to carry goods or fare-paying passengers is considered a commercial vehicle. Since these vehicles profit far more from travel and especially from haste, it's easy to see that circumventing patrolmen would be a great benefit to any industry. Profitable and dangerous. With great power comes great responsibility and, when it comes right down to it, a radar detector is a privilege intended for smart drivers. Your safety is the very reason why these laws were put into effect on commercial vehicles specifically.
|"...there is sweeping federal legislation in place that prohibits the use of radar detectors in every state in the union."||
10,000 Pounds: The Legality of Commercial Vehicles and Radar Detectors
Some states have very specific legislation against commercial vehicles, which can tack state charges onto a ticket, but it's important to understand is that there is sweeping federal legislation in place that prohibits the use of radar detectors in every state in the union. Under U.S. federal law, it is illegal for any and all commercial vehicle over 10,000 lbs. to use a radar detector. To make that even more clear, here is a brief excerpt from the official document:
CHAPTER III--FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION<
PART 392--DRIVING OF COMMERCIAL MOTOR VEHICLES
Subpart G--Prohibited Practices
Sec. 392.71 Radar detectors; use and/or possession.
(a) No driver shall use a radar detector in a commercial motor vehicle, or operate a commercial motor vehicle that is equipped with or contains any radar detector.
(b) No motor carrier shall require or permit a driver to violate paragraph (a) of this section.
[58 FR 67375, Dec. 21, 1993]
Laser jammer might be permitted in a private vehicle in many U.S. states, but it is illegal for such a device to be used in any commercial vehicle crossing state lines and weighing over 10,000 pounds. If you're carrying cargo, stay away from laser jammers.
Just because your vehicle is under the 10,000-pound limit and driving outside of Washington D.C. or Virginia doesn't mean you're totally in the clear. There's still one place where you can never enter with an active radar detector: a military base. It is against the law for you to enter a military installation with a radar detector visibly mounted to the sun visor or windshield. Don't worry, you won't be fined or jailed for having a radar detector, you'll simply be asked to remove it until you leave the base. If you refuse to turn the device off and store it away somewhere like your glove box then you will not be granted admittance onto military grounds.