Chennai Metro is a rapid-transit system serving the city and was partially commenced on 29 June 2015. To improve the city's public transportation system and prepare the city for the future commuting needs, the Chennai Metro was planned and approved by the state cabinet during 2007 for which construction began on 2009.[368] Phase I of the Chennai Metro network consists of the Blue Line and the Green Line covering a length of 45.1 kilometres (28.0 mi) consisting of 40 stations with Alandur and Chennai Central serving as interchanges.