Construction on a new tunnel across the Huangpu River from the southern downtown area will begin this year, city officials said yesterday.

The project, called Longyao Road Tunnel, will link the Shilong Road in Puxi and Yanhua Road in Pudong.

"It will greatly facilitate the traffic connection between the Xuhui District and Pudong," said Cai Yifeng, a senior engineer of the Shanghai Transport Planning Institute.

The tunnel will cost 3.4 billion yuan (US$453 million) and will stretch 4.35 kilometers, including a main section of 3.65 kilometers.

It will have four traffic lanes and is designed for cars to travel at a speed of 40 kilometers per hour, the plan shows.

The Puxi end of the tunnel will be close to the intersection between the Shilong and Longwu Roads.

Its main entrances are in the east of the Tianyaoqiao Road in Puxi and in the west of Jiyang Road in Pudong.

The Pudong entrance is close to the World Expo Site, so the tunnel will be a major traffic artery for the fair.

The tunnel will cut travel time for commuters between the Shanghai South Railway Station and the Pudong New Area by about 30 minutes.

Bus stops will also be stationed near the tunnel entrances, officials said.

City planners have also decided to widen the Chengshan Road between the Changqing Road and Yanggao Road in Pudong. The tunnel will be open by 2010. Currently, the city has 10 links across the Huangpu River.