The Chennai Mass Rapid Transit System, a state-owned subsidiary of Indian Railways, is a metropolitan elevated railway line in Chennai, India. Operated by the Southern Railways, it is the first elevated railway line in India and also the country's longest elevated corridor spanning 17 km. Although it is segregated from the Chennai Suburban Railway, they both are operated by Southern Railway and are integrated in a wider urban rail network. Built at a cost of 15,710 million, the line runs within the city limits from Chennai Beach to Velachery, covering a distance of with 18 stations, with an average daily ridership of 100,000 commuters. Connecting the central business area of old Madras with the IT corridor, the section has a potential capacity of 425,000 passengers a day. In 2011–2012, MRTS registered a revenue of 198.9 million, registering a 16.25 percent increase, with 134 trains plying across all the 17 stations. The MRTS is planned to be taken over by the Chennai Metro Rail Limited in upcoming years, thereby bringing all the elevated tracks and underground tracks inside the city under one organisation. History Planning The well-established Chennai Suburban Railway network, which dates back to 1931, began services on the metre gauge line from Beach to Tambaram. Two more suburban networks, Chennai Central–Arakkonam and Chennai Central–Gummidipoondi began operations in 1985 from the then newly built Moore market complex annex of the Chennai Central railway station. In 1965, the Planning Commission set up a study team on metropolitan transport to assess the adequacy and limitation of existing transport facilities in the cities of Calcutta, Bombay, Madras and Delhi to determine the feasibility of different modes of transport and recommend phased programmes for development of transport facilities. In a means to supplement the existing suburban rail network in Chennai, a number of surveys were conducted in the 1960s including the surveys by the Madras Area Transportation Study Unit (MATSU), which was set up by the Planning Commission during 1968–1970 and the Metropolitan Transport Project (MTP), which was established by Indian Railways in July 1971. The surveys and studies identified eight important transport corridors, including the 39-km north–southeastern rail corridor along the Buckingham Canal. These were soon followed by a feasibility study conducted by RITES, an engineering and infrastructure enterprise of the Government of India, on behalf of the state government. The study results were submitted in 1975, suggesting a rail-based mass transit system