Of all the things that have changed in China over the past 30 years, transportation has undergone one of the most obvious of transformations. Where burghal streets already swarmed with bicycles, they are now abounding of automobiles. Cars clog intersection and expressways. Their exhaust clouds the sky and the air is full of the sound of horns. But zipping through the congestion is the vanguard of another transportation revolution: vehicles that use no gas, emit no exhaust and are so quiet they can surprise the unwary pedestrian.

In China, electric bicycles are leaving cars in the dust. Last year, Chinese bought 21 million electric bikes, compared with 9.4 million autos. China has four times as many e-bikes with is now has about 25 million cars on the road. Thanks to government encouragement and a population well versed in riding two wheels to work, the country has become the world’s leading market for the cheap, green vehicles, helping to offset some of the harmful effects of the country’s automobile boom. Indeed, China is already ahead of the game as engineers around the world scramble to create eco-friendly, plug-in electric cars. Says Frank Jamerson, a former GM engineer turned electric-vehicle analyst: “What’s happening in China is sort of a clue to what the future will be.” (See the top 10 green stories of 2008.)

Right now the approaching buzzes forth at a sedate pace. Government regulations limit the top speed of electric bicycles to about 12 mph. But manufacturers are architecture bigger and bigger machines with acceleration regulators that are calmly removed. E-bikes that are basically pedal-powered machines with an electric addition are accepted in cities like Beijing and Shanghai, but e-scooters with added motors and top speeds of about 30 mph, fast abundant to battling mopeds, are growing in popularity.

The e-bike boom owes much to Chinese policy. The government made developing e-bikes an official technology goal in 1991. Major Chinese cities have extensive bicycle lanes, which means riders can avoid the worst of rush-hour congestion. In cities such as Shanghai, local governments have drastically raised licensing fees on gas-powered scooters in recent years, effectively driving hoards of consumers to e-bike manufacturers.

The relative simplicity of the machines and their components has encouraged a huge number of electric bike companies to open in China. There were 2,700 licensed manufacturers, and countless additional smaller shops in 2006. Rising to the top of the abundance is not easy. Zhang Chongshun, an auto parts factory executive who recognized the potential of the field found the leading manufacturer Xinri (the name means “new day”) in 1999. Last year it churned out 1 and in its first year Xinri built less than 1,000 bikes.6 million.