Magnetically levitated, tube-based transportation system would travel at rocket speed

IEEE Spectrum : Passive magnetic levitation is the key to a proposed next-generation high-speed mass transit system. Hyperloop Transportation Technologies (HTT), a startup based in Southern California, is working on the concept with scientists from Lawrence Livermore National Laboratory, where the technology was first developed. The HTT system would consist of a magnetically levitated capsule that travels at the speed of sound inside a reinforced vacuum tube laid atop pylons. Levitation is achieved by lining the bottom of the capsule with a Halbach array of permanent magnets and running it over a railbed of electromagnetic coils. Such a system could cut travel times between major cities significantly. According to the HTT website, commuters would be able to go from New York City to Washington, DC, in just half an hour. Said to be cheaper and safer than active magnetic levitation systems, such as MagLev, which require power stations along the track, the HTT system is one of several levitated trains currently in development.