Daijiworld Media Network - Chennai
Chennai, Dec 23: Chennai is set to witness a major infrastructure boost with the proposal for India’s longest double-decker viaduct along the GST Road, spanning 18.4 km between the Kalaignar Centenary Bus Terminus (KCBT) at Kilambakkam and Chettipunniyam near Mahindra City.
The Tamil Nadu government has granted in-principle approval to the National Highways Authority of India (NHAI) to construct a six-lane elevated highway with provisions to accommodate a metro rail corridor on the upper deck. Once completed, the project is expected to be the longest double-decker viaduct in the country and among the longest globally.
The proposal was finalised during a recent high-level meeting chaired by Chief Secretary N Muruganandam, with officials from the state highways department, Chennai Metro Rail Limited (CMRL), NHAI and other agencies in attendance.
According to official sources, the elevated corridor will feature a six-lane roadway on the lower deck, while the upper level is being structurally designed for future metro rail expansion. The second phase of the metro project is proposed from KCBT to Chengalpattu, following completion of the Airport–KCBT metro line, which is awaiting Union government approval.
NHAI officials said earlier concerns regarding alignment for future metro expansion along the Kilambakkam–Chengalpattu stretch have now been resolved. The state government has agreed to bear the additional cost required to incorporate structural provisions for the metro corridor.
“The revised Detailed Project Report (DPR) will include the updated metro alignment. Once approvals are obtained, tenders will be invited,” an NHAI official said.
The proposal, first mooted in 2022, had faced delays due to differences over metro alignment. The revised DPR is also expected to retain a dedicated bus lane on the elevated corridor to ease congestion in south Chennai.
The project was initially estimated to cost around Rs 3,400 crore and includes entry and exit ramps at multiple locations. Earlier, the state government approved the extension of Chennai Metro’s Blue Line from the airport to KCBT, with stations planned at Pallavaram, Chromepet, Tambaram and Vandalur, and funds allocated for land acquisition and utility shifting.
Officials said the proposed corridor would significantly reduce traffic congestion on GST Road while supporting future public transport expansion in south Chennai.