some sort of light flashes when you drive by esecially at night BUT it's not the camera flash. just sets up the vehicle to be lit up if it is speeding.
Sensor strips in the road count one way only eg (1, 2, 3, 4) so if you are driving towards the lens side of camera you can't get done as the sensors can't count backwards and they are not allowed to photograph your face, legal reasons.
This is only what i know about NSW suburban fixed speed cameras and don't take what i say as gospel.