While driving South on I-95 close to Exit Donald Ross Road you will notice a white line in the far left lane (it’s half way up the bridge that goes over Donald Ross Road). There is a traffic camera aimed at the road right on top of the bridge. About a 1/4 to 1/2 mile down the road there will be another white line. Somehow the cops can time your distance between the white lines and thus calculate your speed, and often there will be 5 to 8 cop cars waiting under the next overpass. I don’t think there’s a plane involved. I have driven there doing 80 (70 mph limit) and wasn’t stopped. Either all cars were busy writing tickets, or they only get the real bad ones