Mumbai suburban railway services carry _________ million passengers daily.
The Mumbai Suburban Railway, popularly referred to as Locals forms the backbone of the city's transport system. It is operated by the Central Railway and Western Railway zones of the Indian Railways. Mumbai's suburban rail systems carried a total of 7.5 million passengers every day in 2007. Trains are overcrowded during peak hours, with nine-car trains of rated capacity 1,700 passengers, actually carrying around 4,500 passengers at peak hours. The Mumbai rail network is spread at an expanse of 319 route kilometers. 191 rakes (train-sets) of 9 car and 12 car composition are utilized to run a total of 2,226 train services in the city.