Database for cops would probably be the phone book. Cop cars have radars built in so as soon as you see a cop, you're warned. They dont stay in the same spot all the time anyways so a Database for cops is pretty much useless. I dont think you need a database for cameras as all the cameras have warnings at least 200 feet before the camera. There are no speeding cameras in the hiway, only at intersections. Besides cameras are very very rare in the US.