skytran [View all]

I've always been a fan of this concept. They've got the first demo track going up in 2014.

http://en.wikipedia.org/wiki/SkyTran

SkyTran is a patented Personal Rapid Transit system first proposed by inventor Douglas Malewicki in 1990, and under development by Unimodal Inc. Lightweight two-passenger vehicles suspended from elevated passive magnetic levitation tracks are expected to achieve the equivalent of over 200 miles per gallon fuel economy at 100 miles per hour or faster.[1] A prototype of the SkyTran vehicle and a section of track have been constructed. Inductrack, the proposed magnetic levitation system for SkyTran, has been tested by General Atomics with a full scale model.[2] UniModal Inc. is now collaborating with NASA to test and develop SkyTran.[3]



http://www.skytran.us/videos.html

The big advantage here is it's cheaper than traditional transit. You don't lose real estate the tracks travel over since they're "up in the air" and, being electric, quiet. The only footprint is for the support poles.