The ability to add/delete any consist anytime anywhere during play and save. A working dispatchers panel. that would then give you the ability to have simple AI that could drive the route you give them based on the signals you set- Add in programmable industry tracks, That would give you the ability to simulate operations in real time, no special editor necessary. That would also give reason to have an operational hump yard @ Cumberland. Give it the ability to have a multiplayer option- I would be remiss if I did not ask for physics that actually attempt to mimic RL.
