As of 2019, which is the longest continuous subway tunnel that is still in use?
Line 3 of the Guangzhou Metro is a 67.3 km (41.8 miles) rapid transit line connecting Panyu Square to Tianhe Coach Terminal. The entire line, including all track and stations, is located in underground tunnels. Its 60.4 km (37.5 mi) main branch, excluding the 6.9 km (4.3 mi) branch between Tianhe Coach Terminal and Tiyu Xilu, is the longest continuous subway tunnel in the world, and the longest rail tunnel of any kind (surpassing the Gotthard Base Tunnel in Switzerland).
The length of the Beijing Subway Line 6 is: 53.4 km (33.2 miles).
The length of the Beijing Subway Line 10 is: 57.1 km (35.5 miles).
The length of the Wuhan Metro Line 2 is: 44.347 km (27.556 miles).