China's first underwater highway interchange is completed

The construction of the main structure of the east artificial island of the Shenzhen-Zhongshan cross-sea link project was completed on Tuesday, marking the official formation of the country's first underwater expressway interchange, according to Guangdong Communications Group.

Once fully completed, it will give full play to the project's important role as the core transportation hub of the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) and promote the formation of the "one-hour commute circle" between major cities in the GBA, the group said.

The Shenzhen-Zhongshan cross-sea link integrates two bridges, two artificial islands, a two-way eight-lane tunnel and underwater channels. The east artificial lands started construction in 2017. 

It is connected to the underwater tunnel and realizes the efficient and smooth connection between the project and the road network such as the Guangzhou-Shenzhen Coastal Expressway.

The island has a land area of 343,800 square meters, equivalent to 48 international standard soccer fields and is equipped with tunnel works, rescue docks and supporting houses for power supply and distribution.

Upon completion, the underwater interchange of the east artificial island connects Shenzhen, Zhongshan, Guangzhou and Hong Kong, realizing fast and convenient traffic conversion and inter-connection between the mega-cities.

On June 11, the Shenzhen-Zhongshan underwater tunnel, the world's longest and widest steel-shelled concrete undersea immersed tunnel, finished construction, and another part of the Shenzhen-Zhongshan link, the Lingdingyang Bridge with total length of 17 kilometers, was finished in April.

The Shenzhen-Zhongshan link is expected to open to traffic in 2024. It will reduce commute time between the two cities from two hours to just 30 minutes, according to the Xinhua News Agency.

After completion, the link project will greatly enhance transportation in the Greater Bay Area, encompassing the special administrative regions of Hong Kong and Macao, and nine cities in Guangdong Province, including the capital Guangzhou and economic hub Shenzhen.