Olympic host city Beijing and six co-hosts are making last-minute efforts to overhaul public transport systems in order to support the upcoming Olympic Games.

Beijing's streets are busy with bicycles, buses, taxis, and trucks.

As China has become more industrialized, Beijing and other large cities have struggled with air pollution from cars, factories and construction.

With the Olympic Games breathing down Beijing’s neck, the city is racing against the clock to ensure it meets one of the commitments it made when it won the bid for the games in 2001: blue skies. By Anumita Roychowdhury

China has introduced cleaner fuel standards in its capital Beijing, its latest effort to curb the city's notorious pollution ahead of the Olympic Games in August.

Despite a persistent gray haze, officials said Tuesday an exercise that removed more than 1 million private vehicles a day from Beijing's gridlocked streets was a success that could mean a clearer sky during next summer's Olympics.

Effectivity date: 30 December 2005

Atmospheric Environment, 38, 3443-3452, 2004

Atmospheric Environment, 40(18), 3251-3262, 2006

Chinese Science Bulletin (SCI), 52, 608-615, 2007

Atmospheric Research, 84(2), 169-181, 2007

Li Kunsheng, EPB