The state of Bihar has a number of bridges, extending from few metres to a few kilometres. The history of long bridges goes back to the British Empire when the site for the Koilwar bridge (Abdul Bari bridge) was surveyed in 1851. Since then a number of small and large bridges have crept up. Some are even largest of their kind. Mahatma Gandhi Setu, joining Patna and Hajipur was India's longest river bridge from 1982 to 2017.