Citizens ride bicycles to work in Taiyuan, capital city of North China's Shanxi province on the World Car Free Day, Sept 22, 2011. With the year's theme "Green Transport & Future City", 143 Chinese cities have taken part in World Car Free Day campaign and people are encouraged to take public transport, ride bikes or walk. The campaign first originated in France in 1998 and initiatively launched in China in 2007, aiming to promote environment-friendly transport and ease the city's traffic congestion. [Photo/Xinhua]

Citizens ride bicycles to work in Taiyuan, capital city of North China's Shanxi province on World Car Free Day, Sept 22, 2011. [Photo/Xinhua]