TL;DR
Lock blocks where a manual train couldn't stop before entering like with automatic trainsWhat ?
Automatic trains block paths temporarily that they're planning to travel rather this isn't possible with manual trains as they don't have a predetermined route, so why not just block all routes that the train could take within stopping distanceWhy ?
the benefit to the train AI is that if the user makes erratic choices they're planned for and the auto trains won't plow into blocks at full speed that the manual train might make or want to make. The user still has to be aware of automatic trains but they act in a more predictable manner (ie acting like the manual train is a runaway train and getting out of it's way or at least not getting in it's way if possible) this would lead to junctions being cleared by automatic trains that a player might want to use too and generally fewer accidents.I realise this is solvable simply by more careful driving but I think it would add a lot to manual trains.