As far as anyone's found so far. I know people have been using them for travel. You can get across town in a day or two- or maybe three- with them. They're just empty and away from the cold of the rest of the town. You can sleep in them too, just like the skyways in the Industrial Zone. So it wouldn't take us weeks to get back over to you, or for you to get wherever Royce ends up reviving.

[ Because Sylar is assuming he will. ]

I really wish we'd opened them up before, but I'm assuming that the Admin had to 'reset the origin trapdoor' or whatever it was we were supposed to ask her about back then.