Shanghai's 11th subway line started trial operation Saturday, ahead of the opening ceremony of the futuristic Shanghai Expo on May 1.

The new line made the city China's first to have more than 420 kilometers of metro routes in service.

The Metro Line 10, 29.6 kilometers long, would be officially open after a three-month trial period, said an official of the municipal government.

Line 10 will see busy traffic during the six-month Shanghai Expo as it passes Fudan University, Shanghai Jiaotong University, Tongji University and the downtown business districts.

Shanghai had its first metro line on April 10, 1995, which carried 180,000 passengers on its 16 kilometers route a day. Now the city has 11 metro lines with an average of 4.78 million tickets sold daily.