Yeah, the lawz are using the instant on KA band that takes about a second to get your speed. The only way you know that they are scanning is when they pull the trigger on it, and they are either scanning you or some poor fool ahead of you, which gives you time to slow down. Then there is the LIDAR (laser). If you ever see LASER across your detector, you may as well pull over or try to play it off. It gets your speed in about 1/3 of a second! A cop accually let me scan someone, and it was damn fast.