A rapid transit, underground, subway, or metrom is an electric passenger railway in an urban area with high capacity and frequency, and which is grade separated from other traffic. The first rapid transit system was the London Underground, which opened in 1863. Some of the major rapid transit systems currently in operation in more than 160 cities are in New York, London, Paris, Madrid and Shanghai. While New York system has the most stations (468), Shanghai has the longest network (420 kms).
Beijing subway's first line opened in 1971, but the progress was slow until 2001, when the city won the bid to host the 2008 summer Olympics. The network currently has has 9 lines, 147 stations and 228 km of tracks in operation. A mega expansion is currently under progress, building 10 more lines until 2015. Two more lines will be added before 2012, and the network will reach 420 kms by then, equaling the current longest Shanghai network.
The system currently in operation in the National Capital Region in India, was first opened in 2002. Though planning started in 1984, after years of delay, work finally started in 1998. The first phase of the project was completed in 2006 on budget and three years ahead of schedule, which is a a miracle considering the enormous delays associated with infrastructure projects in India. As of June 2010, nearly 100 stations are in operation, and there is a big expansion on as the city hosts the commonwealth games in October 2010. Further 45 stations will be added before the start of the games, including a high speed airport link from central New Delhi.
The metro system in China's largest city, is currently the world's longest with 420 kms of lines in service. Though the line opened only in 1995, since then it has undergone major expansion. It currently has 13 lines in operation, with average daily ridership of 3.56 million in 2009. It will further expand to reach 500 kms by the end of 2010, reaching a mammoth 22 lines and 887 kms by 2020. The world's fastest train in regular commuter services, Shanghai Maglev with a top operational speed on 431 kms per hour is also considered part of the network.