Upon completion, the Chennai Metro will be the first metro project in India that will integrate other public transportation systems and the project is expected to reduce the commuting time by 75% from one end of the city to the other. The system would also takeover the existing Chennai Mass Rapid Transit System, which would be upgraded to operate using the rolling stock of the Chennai Metro as an when approval arrives post discussions between the State and Central Indian Governments. CMRL was recognised by the International Association of Public Transport in 2011.
The construction began in June 2009 and the first stretch covering the seven stations from Koyambedu to Alandur over a distance of 10 kilometres (6.2 mi), began operation on 29 June 2015. Consequent segments of Phase 1, including the last elevated stretch between Little Mount and Chennai International Airport and the first underground segment between Nehru Park and Thirumangalam, will be tentatively inaugurated in August 2016 and December 2016 respectively.