Radar detectors are devices that detect the presence of radar signals used by law enforcement to measure the speed of vehicles. The legality of radar detectors varies by jurisdiction and can depend on a number of factors, including the type of detector, the location where it is being used, and the laws in place in that specific area.In the United States, radar detectors are legal in most states, with a few exceptions. The use of radar detectors is prohibited in Virginia and Washington D.C. and commercial vehicles over 18,000 pounds GVW are prohibited from using radar detectors in all states according to federal law. However, it is important to note that some states and municipalities may have additional laws or regulations regarding the use of radar detectors, so it is always best to check the laws in your specific area.In Canada, the use of radar detectors is legal in most provinces, with the exception of Ontario and Quebec. In these provinces, the use of radar detectors is prohibited and owning one can result in fines or penalties if caught with one.In Europe, the use of radar detectors is legal in most countries, with a few exceptions. In the United Kingdom, radar detectors are legal to own but it is illegal to use them while driving. In Germany, the use of radar detectors is illegal and punishable by fines or penalties. In France, the use of radar detectors is also illegal and punishable by fines and penalties.In summary, the legality of radar detectors varies by jurisdiction and depends on a number of factors. In the United States, radar detectors are legal in most states, with a few exceptions, like Virginia and Washington D.C. and commercial vehicles over 18,000 pounds GVW. In Canada, radar detectors are legal in most provinces, with the exception of Ontario and Quebec. In Europe, the use of radar detectors is legal in most countries, with a few exceptions like the United Kingdom, Germany and France. It is always best to check the laws in your specific area before using a radar detector.