A separate-named northern extension, called Line S1, is started construction in October 2019,[2] construction completed in 2023. Line S1 opened on 31 January 2024 (free trial before formal open during 20-22 January).[3]
Line S1 is 30.4 km in length with 10 new stations (9 in operation, Xiakewan Science City station is under construction), including 10.5 km underground section and 5 underground stations. There are through service between Lines 1 and S1.
Further extension of Line S1 including a Northern extension to Jingjiang (a county-level city),[4] a Southern extension to urban area of Wuxi, and a branch to Sunan Shuofang International Airport.[5]