Piaggio's new offering is, in fact, a scooter--but one with two wheels in front instead of one. The wheels on Piaggio's tripod moped, called MP3, tilt in parallel tandem when the bike takes a turn or the rider leans to the side--so it takes a turn just like a two-wheeled bike. The 200cc bike tops out at around 75 miles per hour, and is highway legal. (See it in action on this video.)

Paolo Timoni, president and CEO of Piaggio Group Americas, which is the North American arm of the Italian parent company of Vespa, Aprilia, and Moto Guzzi, said the bike/trike targets urban and suburban commuters worried about global warming, gasoline prices and gridlock.

The approach isn't new to Piaggio sibling Vespa, which has for the past two years been trumpeting its scooters as green machines in urban centers through mass transit poster ads promoting the iconic two-wheelers as gasoline and time savers in U.S. cities.

Timoni said that the company ran a study prior to launching MP3, based on a hypothetical situation in which 20% of car volume in New York City was replaced by scooters. "We learned that each of those drivers would save ten days a year," he said.

Marketing for the vehicle will launch this spring when Piaggio runs a national road show taking the three-wheeled vehicle to cities, and a national open house at dealerships, talking up the environmental friendliness, savings and practicality of the vehicle. "We will run a traditional print push later in the year," Timoni said.

Piaggio, which also launches a new line of vintage scooters this spring, will roll the MP3 into dealerships in March, with an MSRP around $7,000--which is well above the cost of most scooters and a higher price than the Segway.

But Timoni said it will appeal to experts and beginners. "We are really aiming for two segments with MP3: experts and beginners. Those who seek a performance experience, and those who have never owned a scooter, seeking a transportation alternative."

Ty van Hooydonk, director of product communications for Discover Today's Motorcycling, a division of the Motorcycle Industry Council, said scooter sales are getting a huge boost because of rising gasoline prices and an increased variety of styles, types and sizes. He noted that when fuel prices exceeded $3 per gallon, scooter sales in the U.S. jumped 65% for the quarter.

Marketing within urban footprints makes sense, van Hooydonk said.

"Logically, with automatic transmission, luggage capacity and fuel economy in the 60 to 80 mpg range and beyond, you are looking at vehicles suited to the urban environment," van Hooydonk said.

The sales boom may also reflect diversity of styles and engine sizes in a segment that, until recently, hasn't strayed from the Vespa template.

Yamaha last year launched the Morpheus, a low-slung, arrow-like 249cc scooter that retails for around $5,200--and Suzuki, whose Burgman line of scooters rival motorcycles for power, offers a 650cc Burgman Executive. On the lower end, Yamaha has launched a college-campus-friendly C3, 50cc four stroke.

As for the Segway, inventor Dean Kamen's answer to urban transport, the limitations of its use in traffic and on sidewalks have constrained sales mostly to commercial uses and tour operators--although one can see the rare owner scooting along city streets.