How good is a radar detector at alerting to photo speed traps?
A Photo Radar Speed trap typically uses K or Ka band radar to detect the speed of your vehicle. If you are driving towards the photo radar trap, a superb radar detector (Escort 8500 X50, Bel RX65, Valentine One, Bel RX75 or Escort SR7) will provide 300 feet or more radar alert to a photo speed trap pointing at the front of your vehicle. Depending on your speed, one could adjust speed accordingly in about 2 seconds, thus a good radar detector could alert you in a front encounter with a photo radar speed trap. However, if the photo radar trap is set up to detect your speed from the back of your vehicle as you drive past the camera, then your vehicle gets very close to the radar trap before it can detect the radar signal, generally about 100 feet or less. That is not enough time to adjust your speed; therefore, a good radar detector can not alert you to a rear photo radar encounter in reasonable time.
