A study of all the trails and service centers was made in the 1980s. The outcome of the Main Trail Study (MTS) was a set of district Main Trail Maps (MTM). These maps helped to categorize trails as Main Trails and Local Trails in view of their utility and the importance of the places they linked.

The digitized and elaborated versions of MTMs are called the Transport Infrastructure Maps (TIMs). TIMs are a major milestone in mapping the trail network and trail bridges of Nepal. Recently, TIMs are being made compatible with GIS so that it can be added into District Transport Master Plan (DTMP).