THE tunnel construction plan for the Shenzhen-Zhongshan Corridor has passed an expert review and will be handed to the provincial transportation department for approval, according to a release from the Guangdong Transportation Group on Tuesday.

A world-class project that links city clusters to the east with the west bank of the Pearl River, the corridor is comprised of a 6.8-km tunnel, two artificial islands and two suspension bridges.

The tube tunnel will be the world’s widest immersed tunnel, with eight traffic lanes in two directions and boast a capacity of 90,000 cars per day.

According to Song Shenyou, chief engineer with the Shenzhen-Zhongshan Corridor Management Center, the tunnel project is one of the most challenging projects in the world as the unstable geological condition and the amount of siltation are factors affecting the project. The tubes will be immersed 40 meters under the water.

The 46-billion-yuan (US$6.76 billion) project will connect Shenzhen with Zhongshan and Jiangmen, cutting more than 100 kilometers off the current journey from Shenzhen to the western part of the Pearl River Delta. After the corridor is completed in 2024, a single trip to Zhongshan from Shenzhen will be cut to 30 minutes.

The corridor, along Humen Bridge, Huangpu Bridge, Humen No. 2 Bridge, Hong Kong-Zhuhai-Macao Bridge and Lianhuashan Corridor will form the backbone transportation network by linking ports, airports, intercity rails and expressways of the Guangdong-Hong Kong-Macao Greater Bay Area. (Han Ximin)