I've seen speed cameras work great in Australia when I was there years ago. But they were signed damned well and everyone knew they were there. If you were stupid enough to blow through them, then you deserve a ticket.
Their signage went like this IIRC:
Sign #1 - Photo radar in 1000m
Sign #2 - Photo radar in 500m
Sign #3 - Photo radar in 250m
People would slow down through this section, and then pick back up. But all their cameras were clearly signed.
As for school zones and such. Definitely a major problem with idiots all around. We all saw the footage of the little girl that almost got taken out by the Mazda 6. However...the little girl darted out into traffic with ZERO awareness of what's going on. AND the bus driver did not have the STOP sign out for a long time. It's one example, and I know there's tons of near misses every day unfortunately.
Driver looked like they were speeding, but they were also aware enough to swerve around the little girl (thank God she stopped in time when she heard the honk).
IMO drivers are not always the ones to blame. Similar to this whole 'pedestrians injured safety blitz'...let's see how many of those injuries are pedestrians that just walk out in front of traffic where they don't look up or care what's coming, or how many of them actually get injured at intersections instead of jaywalking blindly and assuming all cars will see them and stop accordingly.
EDUCATION is key to the solution to this problem. Fines, tickets, points, cameras will not solve it if people just don't want to, or know to change their behaviour. Getting a ticket 3 weeks after an infraction will not change behaviour.