Cabinet clears Rs 18,662 crore underwater road

The Cabinet Committee on Economic Affairs (CCEA), chaired by Prime Minister Narendra Modi, has approved the construction of a twin-tube underwater road tunnel beneath the Brahmaputra River in Assam at a total capital cost of ₹18,662 crore.

The ambitious project involves building a 4-lane access-controlled greenfield highway from Gohpur on NH-15 to Numaligarh on NH-715, including a 15.79-km twin-tube Tunnel Boring Machine (TBM) road tunnel under the Brahmaputra. One of the tubes will also integrate railway infrastructure. The total project length will be 33.7 km and will be executed on Engineering, Procurement and Construction (EPC) mode.

The CCEA said this will be India’s first underwater road-cum-rail tunnel and the second such project globally.

At present, connectivity between Numaligarh and Gohpur spans about 240 km via the Kaliabhomora bridge near Silghat, requiring nearly six hours of travel through areas including Kaziranga National Park and Biswanath Town.

The new alignment is expected to drastically cut travel time and provide seamless connectivity between the north and south banks of the Brahmaputra, benefiting Assam, Arunachal Pradesh, Nagaland and other northeastern states. The project is also expected to enhance freight efficiency, lower logistics costs and stimulate socio-economic development in the region.

The corridor will integrate with two major National Highways – NH-15 and NH-715 — and connect to two railway sections: the Rangia-Mukongselek line under the Rangia Division of Northeast Frontier Railway (NFR) on the Gohpur side and the Furkating-Mariani loop line under the Tinsukia Division of NFR on the Numaligarh side.

The project is designed to strengthen multimodal integration by linking 11 economic nodes, three social nodes, two tourist nodes and eight logistics nodes. It will provide improved connectivity to four major railway stations, two airports – including Donyi Polo Airport and Tezpur Airport – and two inland waterway terminals at Biswanath Ghat and Tezpur.

Key economic hubs connected include the Numaligarh Industrial Area, IIDC Titabor, Industrial Estate Nagaon, IIDC Demow and MMLP Jogighopa, among others. The project will also enhance access to important tourism and heritage sites such as Kaziranga National Park and Deopahar Archaeological Site.

Of the total 33.7-km length, 15.79 km will comprise the twin-tube TBM tunnel, along with 1.26 km of road cut-and-cover and 4 km of rail cut-and-cover sections. The civil construction cost is estimated at ₹11,982.36 crore, with land acquisition costs pegged at ₹716.65 crore.

The corridor will improve connectivity to major towns and cities including Numaligarh, Tezpur, Gohpur and Dibrugarh in Assam, as well as Itanagar in Arunachal Pradesh.

The CCEA said the project will have strategic importance, strengthen connectivity between major economic centres and open new avenues for trade and industrial growth in the Northeast. It is expected to generate approximately 80 lakh person-days of direct and indirect employment during construction.

The projected Annual Average Daily Traffic (AADT) for FY25 is estimated at 4,680 Passenger Car Units (PCU), indicating significant demand for improved connectivity in the region.