It doesn't exist now. That doesn't mean it couldn't be built; the article was lamenting America's loss of vision and technological leadership, and I was replyin

It doesn't exist now. That doesn't mean it couldn't be built; the article was lamenting America's loss of vision and technological leadership, and I was replying to your comment that implied that 12 hours between major cities would be too slow, which in the case of coast-to-coast I disagree with.