[hammersklavier]

Maglev will probably be used on the Moon before it has any real application on Earth. Let's face it, due to air resistance, Maglev applications in a terrestrial setting would have an effective speed limit of ~500mph (not that that's not already really, really fast)--which, while linking even more cities in the two-to-four-hour-HSR-butter-zone--suffers from the drawbacks of being MUCH more expensive than conventional HSR to develop (the Transrapid technology should be on a par, cost-wise, with rapid transit to build: they're both elevated concrete guideways; and the Chuo tech doesn't look all that cheap, either). Low-drag environments--like the Moon or a vacuumized tunnel--are where the near-unlimited possible speed of a Maglev can really shine, though--but building the kind of facility on Earth to allow the Maglev to actually run at 900mph would invoke some really ungodly costs (forget trillions and probably even quadrillions, this is probably up in the quintillion--yes, the quintillion--$1,000,000,000,000,000,000). Obviously infeasible.

Which isn't to say I'm against using Maglev in rapid-transit applications. My point is, the speeds at which Maglev starts looking phenomenally attractive, viz. conventional technologies, is so high that a single line would probably cost more than the entire HSR budget of China to build. However, efficiencies at the rapid-transit level, including fantastic braking abilities and the fact that it's much quieter than Els, make it the ideal rapid-transit technology--so long as you're not planning on integrating your new line into an existing (conventional) system. (Come to think of it, that's probably why only the Shanghai airport line has been built so far.) Another drawback is that what makes the Transrapid tech so good for Els makes it terrible for subways--the cost of building a small elevated concrete platform in your box tunnel is several times more expensive than sticking some rails over your precast concrete ties--so it would be an effective solution for a city looking to invest in rapid transit only. Hm.

By the way, as far as Personal Rapid Transit (PRT) goes, it's a joke--a red herring--you would be spending the same amount on it as on a Maglev line (slightly more than a conventional line, when you factor in the largely-untested nature of the technology) to move only a small fraction of the people the other two technologies can move! This scheme is a product of its time--but one that can never, ever hope to be successful in the real world. (There's a reason Republican politicos love to use these schemes, usually sold like snake oil--including the "possibility" of using the lines to transport cargo, which, a-hem, you can technically do, if you had the inclination to, on extant Els anyway (utilizing specialized non-FRA-compliant equipment, of course)--as unobtainable standards to dissuade us from funding the messy compromises we must make in order to have a mass transit system that, you know, actually works.)