For railroad models, there always are some limitations. Big ones are time, money and space. But, think a moment: would you like to have a railroad model empire as large as you want?

The concept by Linn Westcott:

"Linn Westcott has made the suggestion, perhaps in the jest but with much reason, that if CTC is desired, the existing layout should be operated using conventional dispatching and another division created by operating with CTC. The new division would not physically exist. It would be represented by an electrical circuit simulating trains responding to actions of the dispatcher by lighting lamps on the CTC board in an appropriate manner." (Source: Paul Mallery: The Complete Handbook of Model Railroad Operation, p. 56; Tab Books, 1979).

Are there any realizations?

There are many examples of hardware divisions (= the real railroad models) and software divisions (for example: those of "Train Dispatcher Software".

But: are there any examples of connected operating?