How close can you get?
In order to maximize the space for trains, we need to minimize the space between tracks. The operating separation is 1 3/4″ rather than 2″. This allows for an extra siding.
A should have been railway

In order to maximize the space for trains, we need to minimize the space between tracks. The operating separation is 1 3/4″ rather than 2″. This allows for an extra siding.