Elders ride bicycles as they participate in a campaign to promote the idea of the Car-Free Day in Hohhot, capital of north China's Inner Mongolia Autonomous Region, on September 22, 2009. This Tuesday is China's third Car-Free Day and people are encouraged to walk, ride bikes or take buses instead of driving their cars. [Xinhua]

Locals ride bicycles during a public awareness event to mark the Car-Free Day in Haikou, capital of south China's Hainan Province, on September 22, 2009. This Tuesday is China's third Car-Free Day and people are encouraged to walk, ride bikes or take buses instead of driving their cars. [Xinhua]