It seems pretty obvious to me that some variant on the vacuum maglev train is the long-term solution to travel on Earth. It's the only way, really, to get past

It seems pretty obvious to me that some variant on the vacuum maglev train is the long-term solution to travel on Earth. It's the only way, really, to get past the air problem. I doubt we'll ever see mass supersonic transport - a far riskier and more inefficient game of fluid dynamics russian roulette. It's not going to happen overnight, though. We're waiting on a few technological breakthroughs before it becomes viable. Fully automated robotic tunnelling and construction, for one. Automated manufacturing of those robots. Much improved materials science, probably nanotech-enabled. But when these technologies come, it's inevitable that we build such a network. The time isn't right for vactrains but it will be eventually. The future is here, it's just not evenly distributed - and this particular future has been creeping forward for literally centuries. Give it a few more decades and we'll see the real hyperloop!