India’s first and world’s second underwater road-cum-rail tunnel under the Brahmaputra River is set to be constructed in Assam after the Cabinet Committee on Economic Affairs on Friday, 14 January, approved the project aimed at strengthening regional connectivity.
The approval covers construction of a 4-lane access-controlled greenfield corridor from Gohpur on NH-15 to Numaligarh on NH-715, incorporating a 15.79 km twin-tube tunnel with two lanes in each tube and provision for railway infrastructure in one tube. The project will be implemented under the Engineering Procurement Construction mode at a total capital cost of ₹18,662.02 crore.
The project comprises a twin tube TBM road underwater tunnel forming part of a total 33.7 km alignment connecting Gohpur and Numaligarh.
At present, connectivity between Numaligarh on NH-715 and Gohpur on NH-15 is approximately 240 km via the existing Kaliabhambhora road bridge near Silghat on NH-52, requiring around 6 hours of travel through Numaligarh, Kaziranga National Park and Biswanath Town.
The new alignment will provide direct 4-lane access-controlled greenfield connectivity with a road-cum-rail tunnel beneath the Brahmaputra. It will be the first underwater road-cum-rail tunnel in India and the second globally.
The corridor integrates with two major National Highways – NH-15 and NH-715 – and connects the Rangia-Mukongselek Railway Section under Rangia Division of NFR on the Gohpur side and the Furkating-Mariani loop line section under Tinsukia Division of NFR on the Numaligarh side.
The total civil cost of the project is ₹11,982.36 crore, with land acquisition cost of ₹716.65 crore and total capital cost of ₹18,662.02 crore. The tunnel component includes 15.79 km twin tube TBM tunnel with railway provision, 1.26 km of road cut-and-cover and 4 km of rail cut-and-cover sections.
The project will connect 11 economic nodes, 3 social nodes, 2 tourist nodes and 8 logistic nodes, while strengthening multi-modal integration by linking 4 major railway stations, 2 airports and 2 inland waterway terminals.
Employment generation potential is estimated at approximately 80 lakh man-days of direct and indirect work. The Annual Average Daily Traffic in FY-25 is projected at 4,680 Passenger Car Units.
The development is expected to reduce logistics costs, improve freight efficiency and strengthen connectivity across Assam and other North-Eastern states.
