Prime Minister Narendra Modi will flag off India's longest railroad bridge Bogibeel in Assam on December 25. The prime minister will flag off the Tinsukia-Naharlagun Intercity Express, which will pass through the bridge five-days a week, allowing people to commute between Assam and Arunachal Pradesh faster.  

 The 4.9 km-long bridge on Bramhaputra river boasts of being Asia's second longest rail-cum-road bridge and has been completed 16 years after first announcement by then prime minister Atal Bihari Vajpayee. 

Here are the 10 interesting things to know about India's longest rail-cum-road bridge:

• Bogibeel is a 4.9 km-long bridge on Bramhaputra river.
• It is Asia's second longest rail-cum-road bridge.
• The bridge has a serviceable period of around 120 years.
• Bogibeel Bridge is India's only fully welded bridge.
• Estimated cost of the bridge is Rs 5,900 crore.
• It cuts travel time from Assam to Arunachal Pradesh to four hours.
• It will cut train travel time from Delhi to Dibrugarh by three hours.
• The bridge has a two-line railway track on the lower deck and a three-lane road on the top deck.
• For the first time in Indian Railways, the girder has steel floor system for railway tracks and concrete for road.
• PM Modi will inaugurate the bridge on Tuedsay, 16 years after it was announced by then prime minister Atal Bihari Vajpayee.

(With inputs from PTI)