Passengers exit from the Beijing West Railway Station of No 9 subway line in Beijing, capital of China, Dec 31, 2011. Beijing put three subway lines into operation Saturday as the city seeks to expand the rail transit network to ease severe traffic congestion. The lines include an extended section of the current No 8 Line, a section of the existing No 15 Line, and the southern section of the new No 9 line. [Photo/Xinhua]

Passengers buy tickets from self-service machine at the Beijing West Railway Station of No 9 subway line in Beijing, capital of China, Dec 31, 2011. [Photo/Xinhua]