Passengers wait for a train at a station of subway line No 3 in Tianjin, North China, Oct 1, 2012. The 29.7-kilometer-long subway line, which has 23 stations, was put into a trial operation on Monday. (Xinhua/Yue Yuewei)

Photo taken on Oct. 1, 2012 shows the station routeway of Tianjin Railway Station of subway line No 3 in Tianjin, North China, Oct 1, 2012. The 29.7-kilometer-long subway line, which has 23 stations, was put into a trial operation on Monday. (Xinhua/Yue Yuewei)

Passengers are seen on a train of subway line No 3 in Tianjin, North China, Oct 1, 2012. The 29.7-kilometer-long subway line, which has 23 stations, was put into a trial operation on Monday. (Xinhua/Yue Yuewei)