"It's a 'podcar,' also called 'personal rapid transit' -- a system of vehicles that provide on-demand, private, nonstop travel. These vehicles can carry people or light freight. They ride on small, overhead guideways -- like a monorail or people mover -- above existing roads, and are powered entirely by electricity. Picture the car as an elevated, driverless taxi. It's under computer control, so there would be no accidents, thereby saving lives and lowering insurance costs.
Podcars operate on demand, waiting at off-line stations; they can be summoned if one is not available when you arrive at the station. Each vehicle can hold four people, yet the system can be cost-effective even with a single rider for each trip.
The capital cost is low, about $25 million to $40 million a mile for the first systems, which include guideways, vehicles and stations, compared to $100 million to $300 million a mile for light-rail or subway systems. Because it operates over existing streets and sidewalks, there are few costs for rights of way or taking of private property. It is also inexpensive to operate and thus can be available 24/7 and still make an operating profit, depending on pricing policies."