I have been lucky haven't been pinged for over 4 years..... seems more luck than anything.
In Sydney we have a cross harbour tunnel which has a speed camera in it, they have signs up that there is one in it and when you pass it you can clearly see it. Even after that, they average 32 fines/day from the camera !
They had one character who was doing 200 kph+ on a motor bike through the tunnel with a covered license plate. Took them a few months to finally catch him.