The National Highways and Infrastructure Development Corporation Limited has invited tenders for the Gohpur-Numaligarh corridor, advancing plans for a combined road-and-rail tunnel beneath the Brahmaputra. The proposed greenfield corridor will be a 33.77-km four-lane, access-controlled route featuring a 15.79-km twin-tube tunnel, with one of the tubes to incorporate railway infrastructure. The project will be executed under the Engineering, Procurement and Construction model at an estimated cost of Rs 18,662.02 crore (Rs 186,620.2 million (mn) or Rs 186.62 billion (bn)). Civil construction is estimated at Rs 11,982.36 crore (Rs 119,823.6 mn or Rs 119.82 bn) while Rs 716.65 crore (Rs 7,166.5 mn or Rs 7.17 bn) has been earmarked for land acquisition. The scheme includes a one point two six km cut-and-cover road section and a four-km cut-and-cover railway section. State Bharatiya Janata Party officials characterised the initiative as set to deliver India’s first integrated road-and-rail underwater tunnel and possibly the world’s second of its kind. At present the road distance between Gohpur and Numaligarh is around 240 km, with vehicles traversing Kaziranga National Park and the Kaliabhomora Bridge taking five to six hours. The new corridor is projected to reduce the distance to about 34 km and cut travel time to approximately 20 minutes. The alignment will connect with the Rangiya-Murkongselek line at Gohpur and the Furkating-Mariani Loop Line at Numaligarh, directly linking NH-15 and NH-715 and improving links to Tezpur, Dibrugarh and Itanagar. Authorities say the corridor will strengthen multimodal links to 11 economic centres, three social centres, two tourism centres and eight logistics centres and improve access to Donyi Polo Hollongi and Tezpur airports, several railway stations and inland waterway terminals. Planners anticipate annual average daily traffic of 4,680 passenger car units and the generation of nearly eight mn person-days of employment during construction. Project backers describe it as a strategic corridor for regional development and defence logistics, noting the central government has invested more than Rs 1 lakh crore (Rs 1 trillion (tn)) in Assam road connectivity over the past 12 years.