The 15.79km-long road tunnel will feature two lanes in each direction and provision for railway infrastructure.
It is part of a new connection between Numaligarh and Gohpur aimed at reducing the current six-hour journey time between the two cities.
The Ministry of Road Transport & Highways says it is India’s first underwater road and rail tunnel.
“The project will provide significant benefit to Assam, Arunachal Pradesh, Nagaland and other north-eastern states. This will enhance the efficiency of freight movement, reducing logistics cost and driving socio-economic growth in the region,” the Ministry said.
Cut and cover will be used to excavate 1.26km of the road tunnel and 4km of the rail tunnel.
