Technologically speaking, it's a perfectly possible thing to do, writes Tim Fernholtz at Quartz. The problem is the high cost of infrastructure development, something have everybody (whether they want to built a train, a highway, or a futuristic hyperloop) tends to underestimate. That's particularly a problem given the fact that whole idea behind Musk's hyperloop is that it could be a cheaper replacement for an expensive high-speed rail line already under development.
Maggie Koerth-Baker is the science editor at BoingBoing.net. She writes a monthly column for The New York Times Magazine and is the author of Before the Lights Go Out, a book about electricity, infrastructure, and the future of energy. You can find Maggie on Twitter and Facebook.