New Delhi, Sept. 8 -- India's Metro rail systems are meant to transform urban travel, replacing endless traffic jams with punctual, predictable journeys, but the travel experience in Mumbai, Bengaluru and Kolkata is getting compromised by too few trains and too many passengers.

Starting with the Kolkata Metro in 1984 in the hope of living up to the global success stories of the New York Subway and the London Tube, India now has 1,000km of operational metro lines, making it the third largest network at a country level, after China and the United States. Close to 350km of lines were added in the last five years. However, there are already complaints of suboptimal services.

Take Bengaluru's new Yellow Line, inaugurated by Prime Minister Na...