Comment by 1718627440

You can still have redundancy in the computation, that isn't prevented by being in the same location.

> Safety critical systems need to work 100% of the time

Railway safety must be safe 100% of the time, but not available 100% of the time. Also the point of a signal box is to make decisions about the order of train assignment to track. You absolutely do not want multiple points of truths for that.