When I lived in Australia they had photo tickets, but in the NT where I lived a police constable was actively manning the camera system. In our town they had one photo radar unit and they carried it in the back of a green Ford Taurus station wagon. The cops would stop the wagon on the side of the road, get out and set up a tripod with the radar/camera unit on it. It was pretty much like a cop running a regular radar unit, but they didn't have to pull you over and write a ticket while other people sped by, so they could generate more tickets faster.
I've thought that was a much better way to do it than having a for profit company (most of them get a share of the tickets they write) issuing the tickets.
As a side note, I had a co-worker drive through town one day, saw the speed green Taurus, made sure they were going the speed limit. The officers would photograph you as you came towards them, then spin around and get another picture of your car after you drove past. As he slowly went past the constable they spun around like they were taking a photo of his rear plate. He couldn't believe it so he drove around the block and came by the constable again. Same thing happened. He went to the grocery store did his shopping and left. On the way back home went through the speed trap again and same thing happened. He was really upset because he knew he wasn't speeding. 2 weeks later he got 3 tickets in the mail........for not wearing his seat belt.
On the original topic, I found this for Virginia.
http://www.schillingshow.com/2010/11...amera-tickets/