What comes first, the radar reading or the visual sighting?
Training dictates that the officer first identify a potential speeder visually, then use radar to confirm or deny that suspicion. This is why jammers and other alleged cloaking devices are of little value. There are times when a radar might pick up a vehicle before it becomes visible such as in foggy or dusty conditions. The author has seen instances where buildings, median barriers or fences would allow a radar to pick up a target out of sight around a corner or curve. This was especially common with older stationary radars in use in the 1970s. Enforcement action was not possible on those vehicles until they had been visually identified and clocked again.
