OK, so, let's say they add a fourth track from Forest Hills to Canton. There is the 2 track Viaduct there, rather limiting an easy add a track project. Past Canton, would it make any sense to add more tracks? With Amtrak going to hourly Acelas and the MBTA potentially eyeing regional rail level service, is there enough capacity with only two rails to also not gum um the Acela's runs? Just seems quad rail w/ the inner tracks dedicated to HSR is the de facto standard else where in the world.