Three new lines, No. 6, No. 8, and No. 9 will be put into use next year, along with at least five new transfer hubs. The projects will enable the city's metro network to cover 230 kilometers, the newspaper said.

The western extension of the No. 2 metro line (6.75 kilometers)and the northern extension of metro line No. 3 (14 kilometers) are put into use by the end of this year, the paper added.

Currently, the city has five metro lines covering 123 kilometers.

Most of the city's subway tunnels are being dug with a single-tube shield to prevent land subsidence during construction, said Yu Jiakang, a senior engineer with the Shanghai Tunnel Engineering and Rail Transit Design and Research Institute.

Yu said the No. 6 line will link Gangcheng Road near the Waigaoqiao Free Trade Zone to Jiyang Road in Pudong.

The first phase of the No. 8 line, which runs 23.2 kilometers, will link Kailu Road in northern Yangpu District to Chengshan Roadin southern Pudong across the Huangpu River.

The first phase of the No. 9 line, which will cover 31.7 kilometers, is designed to link Yishan Road in Xuhui District to Songjiang District. Three stations along the No. 4 line that were delayed by a cave-in three years ago, will go into use next year, completing the city's first ring-shaped metro line.

The final four stations will link Damuqiao Road in Puxi to Lancun Road in Pudong across the Huangpu River.

Currently, more than 170 metro stations are under construction simultaneously as the city expects to build a metro network involving 11 lines, and spanning more than 400 kilometers in time for the 2010 World Expo. Enditem