The Stunning Growth Of The Shanghai Subway System

​Shanghai's metro system is the largest in the world, and it barely existed 30 years ago, when construction had only just begun on the system. The first section, a 4.4 km stretch of the central line, opened in 1993. And then things accelerated (for reference, the green line is 64 km long):

As New York tries to keep its aging subway system in service and major cities around the US are struggling to build metro systems for their residents, Chinese cities are churning out new systems. Guangzhou, which opened the first segment of its system in 1997, already has just over 300 km of tracks — compared to New York's 380 km:

[Wikipedia via Matt Yglesias]