On the metre gauge, one of the longest hauls was on the 1/2 Avadh Tirhut Mail between Lucknow (LJN) and Guwahati. Even in the late 70s, there was no broad gauge link from Northern India to the North-East. So this Mail and its poor cousin the 15/16 Lucknow/Guwahati Express were the only links on this route.