• Image about duo-city-gas-guzzlers-gas-prices-americanway

Rising gas prices and environmental concerns have left car manufacturers scratching their heads for alternatives to traditional gas guzzlers. Until now, they’ve focused on vehicles that use less or cleaner fuel. But what about one that uses none at all?

The German luxury auto makers at Audi are putting a handsome spin on a centuries-old vehicle that runs completely on human energy: the bicycle. In March, Audi introduced the Duo, a hardwood-frame bike crafted in a joint effort with Portland, Ore.–based Renovo Hardwood Bicycles. Calling it a “hand-made work of art that you can ride every day,” Audi is offering the Duo in three models: the commuter Duo City; the Duo Road, a 20-speed performance bike; and the Duo Sport .

As if Audi’s focus on pedal power weren’t enough to make Mother Nature smile, the bike’s wooden frame also makes the Duo a more naturally sustainable and biodegradable set of wheels. From $6,530.