Wait a minute. The Square consisting of Park St., Government Center, State, and Downtown Crossing isn't a hub? That is a central hub as far as I am concerned, and the T subway is for all intents and purposes a Hub and Spoke system, with the hub being the aforementioned square, and the spokes radiating to Wonderland, Oak Grove, Lechmere, Alewife, Boston College, Cleveland Circle, Riverside, Heath St. Forest Hills, Ashmont, Braintree, and even Bowdoin. The system works perfectly for Boston. Also remember that the destination is usually written next to the inbound or outbound, so the destination is clear. One exception of course being Harvard Square, which is probably the worst station outside of downtown for this to be true.
Some other systems if they did this would worry me without this central hub. Such systems include NYC Subway(they use Uptown and Downtown), DC Metro, and London Underground. But with a hub and spoke system, it works perfectly. If you have any suggestions on ways to improve this, I am listening.
Rich "Dino" Martin
A one time happy rider of Arborway and the old Washington St. El.