In February 2025, Chennai Metro Rail submitted two detailed project reports to the Tamil Nadu government, outlining ambitious plans for the city’s metro network expansion. The first proposal is for a 21.8 km extension of Line 5b, which will run westward from Koyambedu to Ambattur, Avadi, and Pattabiram along the Outer Ring Road.
This new line, consisting of 19 elevated stations, is estimated to cost Rs 97.44 billion, which includes the redevelopment of three key road junctions with flyovers. At Koyambedu, this new line would integrate with the ongoing 44.6 km Line 5, expected to be completed by 2028, as well as the existing Line 2.
The second proposal under consideration is a 15.5 km extension of Line 1, running southwest from Chennai’s airport to Kilambakkam. This extension will be elevated, running above a new highway viaduct and serving 13 high-level stations along its route.
The projected cost for this extension is Rs 9.34 billion, including the construction of the elevated highway. The new line will run parallel to Indian Railways’ Chennai–Changalpattu route, connecting key areas like Chrompet, Tambaram, Perungalathur, and Vandalur before terminating at the Kilambakkam Bus Terminal.
