The camera will most likely be set to 30mph limits.
The LA will have thrown some 20 ZONE signs about thinking that will instantly stop little Jimmy from getting run over, possibly due to residential pressure.
All 20 MPH ZONE areas must have regular traffic calming measures throughout the stretch of road, build outs, bumps, chicanes etc etc, to indicate it's not national speed limit (i.e. 30 built-up area).
This is not to be confused with 20 MPH areas that should have regular repeaters on both sides of the road throughout the section.
Reminds me of a women in the local rag a few weeks ago calling for speed humps and 20 MPH on a major A road (built-up 30mph).
A youth had stolen a car, lost control at speed, ploughing through her front window at 3 am.
She was interviewed and one of the arguments for the speed humps was that cars regularly come round the corner too fast while she is reversing off her drive.
She wants her license ripping up if she things it's acceptable to reverse off her drive on to an A road that's unsighted, built up or not.
No mention of how speed humps will stop cars being driven recklessly...