Unfortunately for the speeder, the instant on reading by the detector means, your speed has already been calculated and displayed. Generally, if you get a hit on the radar detector, but you don't get pulled over; the Officer probably chose not to go after you. We have a stretch of highway where 100+ mph in not uncommon. Limit is 70 so a guy could be going 85 or so, get a radar warning, have his speed read by radar and not get pulled over. The reason usually is, the Officer sees that speed all the time and would go crazy trying to catch all the 85 mph cars. He waiting for the 90+ speeds. BTW how did I manage to threadjack this one.