Major bridge - Major bridge is one of which has a total linear waterway of 18 m or more for multiple span and total linear water way of 12 m or more for single span.

Important bridge - The bridges having total waterway of 1000 sq.m or total linear waterway of 300 m or more and the bridges classified as important by Chief Engineer / Chief Bridge Engineer, depending upon consideration such as depth of water way, extent of river training works and maintenance problems.