That sounds interesting for, say, a sci-fi novel, but in the real world I wouldn't want to be responsible for dealing with infrastructure maintenance, earthquakes, tornadoes... Can you imagine if even part of something like that collapsed?
Over the ocean? Would be relatively minor impact even for a catastrophic failure.
The thing is the speeds - anything that can do NYC-LA in minutes is going to have a catastrophic failure mode that kills everyone in a big radius. I am just trying to imagine the London Underground at 14,000 mph.
