NEW DELHI: Prime Minister Narendra Modi today inaugurated three major railway projects in Bihar at an estimated cost of Rs 7000 crore.PM dedicated a rail-cum-road bridge at Patna, inaugurated another at Munger and laid the foundation of additional bridge at Mokama over the River Ganga."Total cost of these three bridges is about Rs 7200 crore and these bridges will go a long way in giving connectivity to north and south Bihar, said a senior Railway Ministry official adding "It will also help in development of North Bihar."Modi laid foundation stone of second Mokama double line railway bridge adjacent to existing Rajendra Pul."PM dedicated Patna Ganga bridge (4.56 km) to the nation and inaugurated the freight operation through Munger rail-cum-road bridge," he said.There are three bridges over the entire 460 km length of the river Ganga in Bihar - one road bridge at Naugachia, a rail-cum-road bridge at Mokama and the third road bridge Mahatma Gandhi Setu at Patna.The inadequate number of bridges had become one of the reasons hindering the development of one of the most populous state in the country.