Growth of some Chinese metro systems
Beijing, currently world's largest and busiest metro system, 690km route length, ridership 3,950m
Shanghai (world's second largest and busiest -676km, 3,880m ridership)
Guangzhou (3rd largest and busiest, soon to be the world's largest, nearing 1,000km length in the next few years)
Shenzhen -4th largest (not to scale) but vying with Guangzhou to be the future no 1. But also will
likely join up with it.
Nanjing -this for comparison is currently about the same size as NYC's system
Chengdu
Wuhan
Chongqing
Tianjin
Hong Kong