This is already happening in the real world, driven by a number of companies which the author does not mention: http://www.ultraglobalprt.com/ http://www.ultra

This is already happening in the real world, driven by a number of companies which the author does not mention: http://www.ultraglobalprt.com/ http://www.ultraglobalprt.com/ http://www.2getthere.eu/ http://www.2getthere.eu/ http://www.vectusprt.com/ http://www.vectusprt.com/ There is currently a system operating at Heathrow Airport; another at a campus in Abu Dahbi; and a third under construction at a national park in South Korea. Additional small systems are in the planning stages for a few more cities / institutions around the world. Skimming the article (unfortunately I don't have time to read it in depth), it appears that the author has basically reinvented http://www.skytran.net/ http://www.skytran.net/ -- a conceptual PRT system which has been kicking around for at least a decade and a half. Real-world PRT systems tend to be considerably more modest in their ambitions, following the "find a tiny niche" strategy of classic disruptive technologies (in the Christensen sense of the term), rather than trying to immediately become the be-all end-all of urban transport infrastructure. Also, skimming the article, it appears that the author makes a number of quite silly mistakes -- curiously, the exact same mistakes that the Skytran people do -- concerning the dynamics and requirements of urban transport. For example, assuming a mean speed of 45 mph for existing transport is grossly wrong: it ranges from about 35 mph to well under 20 mph for more congested cities. (Here in London, it's 16mph -- a number which hasn't changed for over a century). This has some profound implications for how fast you need to go to provide a highly effective alternative, and correspondingly what your grid sizes, turning radii, etc. should be. It looks like the author gets all of this wrong, starting from a few bad assumptions. Disclaimer: I used to work for Ultra PRT, and currently work for a large transport/planning consultancy, advising on PRT installations around the world.