Saurav Gupta
831 km, 508 stations, 20 lines.
490 stations, 27 lines; mainland China's oldest metro system.
402 km, 272 stations; one of the world's oldest metro systems.
Third busiest globally, with 16 operational lines.
399 km; operates 24/7, 365 days a year.
350.42 km, 256 stations, 10 colour-coded lines; ranks sixth globally.
449 km, 263 stations.