What do you get when you cross a bus with a train? A dual-mode vehicle that has the versatility of a bus, the speed of light rail and fuel economy vastly better than either.

Toyota and its truck-making subsidiary Hino Motors have signed on with Japan Rail Hokkaido to develop the vehicles, which carry 25 people and reportedly burn one-fourth the amount of diesel fuel required by conventional buses. Japan Rail started testing them about 18 months ago, and bringing Toyota aboard could speed up development and commercialization of what may be the mass transit vehicle of the future.

Dual-mode vehicles have four rubber tires for road use and four steel wheels for the rails, and it takes less than 15 seconds to go from road to rail and back again. It drives just like a bus on the road, and a hydraulic system raises the tires and lowers the steel wheels as the driver guides the vehicle onto the tracks.