Addressing an event here, the housing and urban affairs minister said from just 8 km in 2002, as many as 425 km of metro lines are operational as of now in 10 different cities across the country.
He also called for the need to devise technologies that would hep in constructing and operating metro systems in sustainable manner in the country.
"With many cities planning for metro rail and in next few years, the network length of the Metro in India is expected to cross 700 km," said an official release, quoting the minister.
He said Delhi Metro, with an operational network of 231 km, was carrying three million people every day and expressed confidence that within a year the network length in the National Capital Region will cross the 350 Km.