What is Personal rapid transit

Personal rapid transit (PRT) is a transport method that offers on-demand non-stop transportation between any two points on a network of specially built guideways. PRT has been reinvented many times because it optimizes standard mathematical models used by transit-planners.
Because it is mathematically optimal, PRT developers and advocates say that it will provide more convenient service than cars, with the social advantages of public transport, and low (excellent) environmental impact. Some advocates estimate PRT's per-mile costs as ranging between $0.10/mile (the cost of a moped) to $0.01/mile (a bicycle is $0.03/mi


from http://en.wikipedia.org/wiki/Personal_rapid_transit