The foundation stone for Assam's Bogibeel Bridge may have been laid in 1997, but it is only today that the double-decker rail-and-road bridge will open to traffic. Prime Minister Narendra Modi will do the honours. Billed as India's longest railroad bridge, the five-kilometre structure spans the waters of the mighty Brahmaputra River. Bogibeel Bridge will connect Assam's Dibrugarh and Dhemaji districts, bordering Arunachal Pradesh. It will cut the travel time between the two points by four hours and help avoid a 170-km detour. With its proximity to the China border, the bridge also has tremendous significance for India's defence and has been built strong enough to support the movement of tanks and even fighter jet landings.