India, Feb. 13 -- The Union Cabinet is expected to take a major infrastructure decision on Friday, with approval anticipated for an ambitious Rs 18,600-crore road-cum-rail tunnel under the Brahmaputra River in poll-bound Assam.

According to reports, the proposal is set to be cleared at one of the last Cabinet meetings chaired by Prime Minister Narendra Modi at South Block before operations shift to the new Secretariat complex.

The proposed tunnel will be the country's first twin-tube underwater structure designed to accommodate both vehicular traffic and railway lines.

The strategic corridor will connect Gohpur on the north bank of the Brahmaputra with Numaligarh on the south, cutting travel time from nearly four hours at present to ab...