Not really cars, not really transit, what is it?

I generally do not indulge in high-tech fantasizing, mostly because I believe that an expectation of technological salvation too often substitutes for doing the best with what we have right now. Traditional ideas and machines (bicycles, passive solar design, organic growing) have evolved specifically to be energy-efficient and they're cheap solutions. But I'm going to now break that rule.

The Boston Globe published a nice overview of the the resurgence of Personal Rapid Transit (PRT), a concept that has floated in and out of vogue for the last fifty years. For those unaware, the idea is to construct a system of individual pods, like cars, that will drive themselves between various nodes on the network. The occupant need only submit a destination and let the computer sort out the route. The pods would be powered electrically, and they would be equipped with sensors to coordinate movements with other pods. Because a new system is set to open in Heathrow Airport and a few others a being proposed, PRT is starting to raise eyebrows.

I'm not exactly sure why the tracks have to be elevated, other than adding some futuristic cache and avoiding current roadways, but that seems to add some unnecessary expenses and aesthetic problems. Otherwise, leaving aside the issue of feasible implementation, this does seem to match many of the positive attributes of transit with benefits of cars. Since the stations would be fixed, you'd think the land use effects would be more like transit than automobiles, promoting walkable density around the cores. Furthermore, eliminating the need for parking is an incredible benefit to facilitating transit-oriented development around stations.

The energy consumption would probably be similar to light rail. On the one hand, you have lower capacity cars. On the other hand, you only have to run them in proportion to fluctuating levels of demand. Apparently, someone secured a grant to study the potential of building solar panels into roadways, but it's difficult to provide protection from heavy trucks. Perhaps the idea of a solar-powered roadway would be more suitable for PRT. The power would go directly into the pods themselves.

Safety seems like a potential concern, but I'd have to defer to the engineers on that one. It couldn't be any more deadly than highways currently are.

And, of course, the convenience of not having to wait for departures and the ability to travel directly to any destination station cannot be underestimated. Unlike owning an automobile, PRT users would not be able to display their social status through the type of vehicle they drive, although I'm sure that human nature will be able to adapt to that hurdle with, say, very expensive clothing.

I'm not an convert yet by any means, just batting around the idea. Do you think PRT would work in certain metropolitan areas?