If you had the choice, would you drive your own car or just sit back and let the car drive you? This is a question someone may ask you in the not too distant future — if Toyota, Nissan and other manufacturers' concept cars make it into production.

Due both to technological trends and government pressure, these companies will have the ability to take some of the driving decisions away from the driver. The type of vehicle that will benefit most from this technology is the so-called personal-mobility vehicle (PMV). And it is Toyota that has been most prolific in this area, so far producing four different concept PMVs over the past five years.

Toyota started this quest to produce a vehicle that is more than a bike but less than a car at the 2003 Tokyo Motor Show, with the breakthrough PM. Best described as a "life pod on wheels," the PM had the unique ability to change its height, dependent on speed. So within the city, it stood tall and upright for both economy of space and maneuverability. But when accelerating toward highway speeds, it stretched out and reclined the driver's pod to the ideal aerodynamic position. At these highway speeds, it was proposed that the PM would have the ability to follow the leader, thus forming an orderly train of co-destination drivers.