For suburban bound traffic, Mumbai has two excellent lines that serve the eastern and western suburbs. They are literally the city's lifelines: everyday, over half a million commuters from Mumbai's far-flung suburbs make their way to downtown offices to earn their living. Trains on both lines run every couple of minutes round the clock (except during the graveyard shift from 00.50 am to 04.00 am) and they offer both first and second-class travel. Fast (F) trains stop only at nodal stations while Slow (S) ones will halt everywhere. First class tickets cost up to four times the ordinary fare, and generally, red-and-yellow striped pillars at stations indicate first class carriages.

In second class the commute is quite a grueling experience, especially during peak hour traffic. Be prepared to feel like a sardine in a tin box, but if you are in a hurry, this is quite the fastest way to travel. Also, remember that all trains have a ladies' compartment, exclusively reserved for women. These are normally less crowded and spare the fair sex from a fair amount of eve teasing, which, unfortunately, is something of a local sport in this city. But don't despair. At its best, the Bombay suburban train is India in microcosm: crowded but friendly and packed with the ethnic diversity of the entire subcontinent.