A well-developed ground transportation system in the Pearl River Delta of South China's Guangdong province has significantly shortened the journey between the cities from days to hours, but the region is expecting more.

The delta is divided into two parts by the Pearl River, which empties into the South China Sea, and it takes two hours to travel from Zhongshan on the west bank to the opposite city of Shenzhen, a vibrant Special Economic Zone, by taking a detour from the north.

But the travel time will be reduced to only 20 minutes after Shenzhong Link, an ongoing mega-project spanning the river estuary, is completed in 2024.

The Link, which will connect cities on both sides of the river, especially Zhongshan and Shenzhen, features two suspension bridges, two artificial islands and an underground interchange that links an immersed tunnel with the bridges.

Founded in 2017, the same year the country decided to initiate the Guangdong-Hong Kong-Macao Greater Bay Area plan, the project aims to improve traffic flow through the province by offering a more direct connection between city clusters on both sides of the river.

"During the rush hour, it may take more time to travel around the highway in the north, which is often overloaded with vehicles. But the completion of the project will largely relieve traffic pressure in the area," said Chen Yue, deputy chief engineer of the Shenzhong Link.

Four traffic lanes were designed in each direction of the Link, which is able to carry up 90,000 cars a day and provide adequate space for large vehicles.

To provide a more efficient way to travel on and across the river, the underground interchange, which sits in one of the artificial islands, has became a highlight of the project.