Line 3 of the Guangzhou Metro is a 65.43-kilometer (40.66 mi) rapid transit line connecting Panyu Square to Tianhe Coach Terminal. The entire line, including all track and stations, is located in tunnels.
Its 57.93 km (36.00 mi) main branch, excluding the 7.5 km (4.7 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).
Line 3 is split into two sections, Shiqiao line (main line, from Panyu Square to Tianhe Coach Terminal) and Airport line (northern branch, Tiyu Xilu to Airport North), and are branded with the colour orange. The line is extremely congested, with numerous sections officially operating over 100% capacity.
There are 4 types of train services offered on the metro line 3:
Tiyu Xilu — Airport North (Terminal 2), Panyu Square — Tianhe Coach Terminal, Panyu Square — Airport North (Terminal 2) and Dashi ← Tonghe (southbound trains only, operating during morning peak hours on working days).
According to en.wikipedia