I guess our worlds aren't that far apart. I have hardly any idea how railway control/signalling works; only that if there's a breakdown the results can be serious. In ATC a single breakdown shouldn't cause a collision, in any accident there is a chain of events, (revealed later), the interruption of any one prevents a potential accident. The safety teams in our part of the world work on analysing where previously unforeseen hazards may contribute to a problem, and developing a fix. Hopefully similar in your world.
We do an assessment every year with a check instructor, plus a full days training yearly in which such things as past incidents, procedure changes, any weak areas are discussed. It's organised by one or both of the senior controllers training/standards. In addition, in the event an individual is having problems, various options are available, ranging from a chat with the team leader to a period of some type of re-training.
Working in a team environment is pretty good for safety/morale etc. Everyone is monitoring everyone else, not in a big-brother sort of way, and there is a lot of support. The main weakness is where management drives the introduction of "efficiency" based procedures that are sometimes poorly thought out or needlessly complex. This happens too often here, and I suspect in many other parts of the world, too.
