Longest metro tunnel

What to remember

In Suzhou, China, two metro lines joined end to end make up a single continuous tunnel 86.542 km long. Line 3 and Line 11 meet at Weiting station, where trains run straight through from one to the other. This combined route, dated 2019 to 2023, is the longest metro tunnel in the world.

Line 3 alone crosses the city from east to west over 45.272 km. It links the Wuzhong District, Suzhou Industrial Park and the Suzhou New District. Trial runs took place from December 6 to December 10, 2019, and official service began on December 25, 2019.

The very longest tunnels carry water, followed by railway tunnels. Within the metro category, it is the through connection at Weiting that lets Suzhou line up such a length underground.