I went through one getting out the way of a speeding cop car.
Went down to check out the photo and explain what happened. Guess what,
no cop car on the whole roll of film to back up my story....
The lesson is if they are in a hurry, too bad. Move over in your own time.
Same goes for red light cameras. They will do you no matter what, so let
the ambulance crash the curb to get around.
Also, if two or more cars can be seen within the photo frame markers then
the camera will fuse the readout and you won't get done.