Boring work for the two-way Mawan undersea tunnel, a key part of the Mawan Cross-sea Passage, has been completed, marking significant progress in the construction of the passage, which is slated to open to traffic within this year.

The passage starts at the intersection of Mawan and Yueliangwan boulevards in the Mawan area and ends at the intersection of the Guangshen (Guangzhou-Shenzhen) Riverside Expressway’s Dachan Bay Tollgate, Jinwan Boulevard, and Xixiang Boulevard in Bao’an District.

Spanning 8.05 kilometers, it includes a 2.5-kilometer road in Qianhai, a 1.1-kilometer undersea tunnel, and a 4.45-kilometer road in the Dachan Bay area, according to the construction plan.

The Mawan tunnel is the largest diameter undersea shield tunnel project in China. A boring machine with a diameter of 15 meters, jointly developed by Germany-based Herrenknecht AG and Shanghai Tunnel Engineering Co. Ltd., has been used for the excavation of the tunnel.

As the first super-large undersea tunnel in Shenzhen, the two-way, six-lane passage is expected to ease traffic congestion in Qianhai. Freight traffic moving in and out of the Nanshan port area will be diverted to the passage, effectively separating it from passenger traffic in Qianhai and the Bao’an CBD and improving the urban environment in those areas, according to Shen Haiyang, an engineer with the city’s transportation public facilities construction center.

In another development, boring work for the Chunfeng Tunnel, which runs along Chunfeng Road in Luohu District, has also been completed. The 5.08-kilometer-long tunnel, scheduled to open to traffic at the end of this year, connects Binhe Road in the west with the Xinxiu Overpass in the east. It includes a 3,600-meter-long underground section.

Upon opening, the tunnel will double the vehicle capacity of this section of Chunfeng Road and greatly improve traffic in southern Luohu.