By Cao Li (China Daily)
Updated: 2008-01-28 08:55

Mayor Han Zheng has expressed concern over the safety of expanding Shanghai's subway, amid calls for a larger network and following the latest snag on one of its lines.

Han said over the weekend that the construction and operation of the city's subway system are reaching "an extreme level", with seven lines, either being started or extended, scheduled to take place this year.

A total of 116 subway stations along these lines are also being built, which will affect transportation on more than 1,000 roads,

"As a result, the city's traffic will face tough times," Han said.

The mayor said he has received numerous requests for a larger subway network, from delegates at the ongoing meetings of the Shanghai municipal people's congress and the Shanghai municipal committee of the Chinese People's Political Consultative Conference (CPPCC).

"But with so much work being carried out at the same time and long lengths of new tracks being put into use, both the construction and operation of Shanghai's subway have reached an extreme level," Han warned.

"I am really worried about its safety."

His warnings follow the latest major hitch in the system, where a train on Line 2, connecting the west and east banks of Huangpu River, broke down in the middle of two stations at about 8:40 am on Friday. Operations were suspended for about 45 minutes.

Bu Chunyan, a journalist who was in the train, said: "It was all dark and there was no ventilation. People were scared and a woman said she was suffocating.

"Some broke the door and the ceiling by force to let in some air."

Bu said that the subway system will need to have better provisions for emergencies and accidents. "What if there is a fire," she said.

With three more lines added on December 29, Shanghai's subway system currently covers 234 km, the 7th largest in the world.

The network is scheduled to be 510 km long by 2012, when 73 percent of downtown residents within the Inner Ring Road and 47 percent within the Outer Ring Road can walk to a metro station.

The system has reportedly been plagued by frequent delays and complaints of unbearable crowds, especially on Lines 4 and 8 during peak periods.

Han said the system will be strained this year and the first half of next year.