The 36-km-long Hangzhou Bay sea bridge linking Shanghai to Ningbo in Zhejiang province will open to traffic on May 1, 2008.

The 36-km-long Hangzhou Bay sea bridge linking Shanghai to Ningbo in Zhejiang province would open to traffic on May 1, the Ningbo government said in Beijing on Friday.

By cutting the distance between the two port cities by 120 km and travel time from four to two hours, the world's longest sea bridge - 3.5 km longer than Shanghai Donghai Bridge, the second longest - will enhance development of the Yangtze River Delta, one of China's most prosperous regions.

Linking Ningbo's Cixi county in the south to Jiaxing in the north, the bridge is expected to benefit Ningbo most.

"Upon its opening, Ningbo will no longer be the end of the region's highway transportation network," deputy Party chief of Ningbo Tang Yijun said.

"Ningbo will become a hub linking cities further south in Zhejiang with Shanghai."

The bridge would also create greater development opportunities for Ningbo's port economy, he said. Ningbo is the country's second largest port by cargo throughput as of last year, with routes linking more than 100 countries and regions.

"After the bridge opens, it would only take about two hours to drive among Shanghai, Haungzhou and Ningbo. This will facilitate regional economic integration among Zhejiang, Shanghai, and the Yangtze River Delta as a whole," he said.

The six-lane bridge, designed to have a 100-year lifespan, comes with an 11.8 billion-yuan ($1.68 billion) price tag. It is estimated that 40,000 vehicles would traverse the bridge daily after it opens. The toll fee is expected to be 80 yuan per vehicle.

The bridge has been designed to accommodate about 100,000 vehicles daily and is expected to approach the designed capacity in 2026.

Wang Yong, vice-mayor of Ningbo, said the bridge's opening would also represent a major milestone in the country's bridge-building legacy.

"We encountered many difficulties other countries haven't during construction, such as dangers caused by marsh gas buried under a 10-km-long mudflat the bridge crosses," he said.

"We had to use more than 250 innovations and engineering breakthroughs since construction began in November 2003," he said.