first of all the cameras we have here in moses lake on the street lights are always recording and as soon as you run a red light or speed through the intersection it snaps 2 pictures in a row then takes the correct time chunk of video of when you went through, they are all recording and taking pics from behind you not in front of you. they pull the pic of your rear license plate and watch the video to see if you actually did or didnt break any law. the senors (also for speed) are in the road so radar detectors and jammers are useless.

our traffic cams are through Redflex: http://www.redflex.com.au/html/usa/index.php
you will see what i mean when you look at the site. if you highlight washington you will see moses lake is one of the few cities to use redflex systems and it looks like alot of places use these in CA. I am network tech for the city and manage all of the patrol cars laptops and pd server, if you have any questions i might ask the chief of mlpd for ya.