Wouldn't rely on this too much! They are mobile and after looking at the locations, I don't see Richmond, NSW listed and yet there was one here somewhere yesterday (Tues).
The only ones you can guarantee being reliable for the location are the fixed ones and you'd have to be plain dumb ass stupid to get your pic taken at one of those with all the warnings before them.
If you can't drive to the speed limit, get one of the IGO MyWAY satnavs of fleabay! You don't have to watch the speedo as the overspeed goes off at 1km over and it tells you so! Most roads on the map have the correct speeds unless they have been changed in the last year or so. Also the school zone waning noise is plain aggravating !! Other than that, the bloody thing would get you lost if you didn't have some idea of where you are going in Sydney.
I much prefer Tom Tom or Mio or one of the better brands but the Igo is there for emergencies in one car.
DH