Wallyhorse, do you realize how many delays this would cause? You seem to not understand that it's not just about TPH, but about schedule. When you have the , , , , and all merging around the same area when their schedules are not interlined with each other, you're going to have trains reaching W 4 St or the Chrystie St cut at the same time, and one of them will have to wait. Combine this with the fact that if a conductor said out of the blue, "This train will be running on the line from here to Essex St, and then on the line to Broadway Junction," people are going to have NO idea what's going on; probably even the most experienced subway riders don't understand how it's physically possible for the to connect with the . It's not like a simple reroute that your average rider can understand like the usual via the for example.