India’s longest double-decker viaduct in Chennai

planned

India’s longest double-decker viaduct, comprising a six-lane elevated highway on the lower deck and a metro corridor on the upper level, has been proposed for an 18.4-km stretch between the Kalaignar Centenary Bus Terminus (KCBT) at Kilambakkam and Chettipunniyam near Mahindra City on GST Road in Chennai. The state government has granted in-principle approval to the National Highways Authority of India (NHAI) for constructing the six-lane elevated corridor with pillars designed to accommodate a future metro line. The detailed project report (DPR) will be revised to incorporate the updated metro alignment, and tenders will be invited once the revised DPR receives necessary approvals. The project was first proposed in 2022, with an estimated cost of Rs 3,400 crore, and includes entry and exit ramps at three locations. The project aims to ease congestion and accommodate future metro expansion.