(Photo/CFP)

This photo, taken in Nantong City, Jiangsu Province on April 9, 2025, shows the construction of the Haitai Yangtze River Tunnel using a tunnel boring machine called "Jianghai," which has a maximum excavation diameter of 16.6 meters.

This project, which began in September 2022 and includes an 11.185-km underwear section, will be the world's longest underwater highway shield tunnel. The six-lane, bidirectional tunnel, designed for speeds up to 100 km/h, aims to ease traffic on the Suzhou-Nantong Yangtze River Bridge and promote integrated development across the river.

This photo, taken in Nantong City, Jiangsu Province on April 9, 2025, shows the construction of the Haitai Yangtze River Tunnel using a tunnel boring machine called "Jianghai," which has a maximum excavation diameter of 16.6 meters. (Photo/CFP)

This photo, taken in Nantong City, Jiangsu Province on April 9, 2025, shows the construction of the Haitai Yangtze River Tunnel using a tunnel boring machine called "Jianghai," which has a maximum excavation diameter of 16.6 meters. (Photo/CFP)

This photo, taken in Nantong City, Jiangsu Province on April 9, 2025, shows the construction of the Haitai Yangtze River Tunnel using a tunnel boring machine called "Jianghai," which has a maximum excavation diameter of 16.6 meters. (Photo/CFP)

This photo, taken in Nantong City, Jiangsu Province on April 9, 2025, shows the construction of the Haitai Yangtze River Tunnel using a tunnel boring machine called "Jianghai," which has a maximum excavation diameter of 16.6 meters. (Photo/CFP)