The same way criminal penalties keep people from robbing banks.
Not really. Robbery is a mala in se crime. Red light running, while potentially dangerous is a traffic violation. Applying the way the gov't handles red light cameras would to bank robbery would be arresting someone who looks like the robber in the banks cctv cameras. The enforcement absuse potentials are a night and day difference.
If a city is encountering a big problem at certain intersections they can do the following:
1. Make sure the lights are timed well so people don't get stuck at every one when driving with the flow of traffic.
2. Make sure the yellows are long enough.
3. Post cops at red lights for a while and ticket the people who run the red lights.
No enforcement abuses, point made.