NEW YORK -- After months of speculation about his mysterious innovation, an inventor unveiled his new device - a gyroscope-stabilized, battery-powered scooter that he hopes will revolutionize short-distance travel.

Dean Kamen and his backers are banking on the Segway Human Transporter to displace cars, leading to a realigned cityscape that's more people-friendly.

The two-wheeled Segway, which looks like a cross between a hand mower and a Razor scooter, travels at up to 12 mph, said Kamen spokesman Dave Chapman.

It's designed to be difficult to fall from or knock over because of gyroscopes that work to keep it upright. Speed and direction are controlled by the rider's shifting weight.

Riders stand upright over the invention's single axle, navigating with a bicycle-like handlebar. A single battery charge can propel the scooter 15 miles over level ground.

Kamen, whose Manchester, N.H.-based DEKA Research and Development company will oversee production, said the Segway requires about 10 cents' worth of electricity for a six-hour charge.

The Postal Service and the City of Atlanta will be among the first purchasers, buying 80-pound heavy-duty models for $8,000 apiece, Chapman said. In February, Atlanta's visitor's bureau employees will begin using the scooters to patrol the tourist district, Chapman said.

Could police departments be next?

A 65-pound, $3,000 consumer model won't be available for at least a year.