Identification of Optimum Route Alignment in Hilly Terrain Using Geographical Information System K.V.Rao Research Scholar Geomatics Engg., Deptt of Civil engg, IIT-Roorkee, India Email: kv_chowdaryin@yahoo.co.in P.K.Garg Professor Department of Civil Engineering, IIT, Roorkee P.K.Sikdar Professor Department of Civil Engineering, IIT, Bombay Road transport plays a significant role in the overall development of a country. India has a fairly good road network except in hilly areas. In hilly areas of the country, connectivity of road network is very poor because these areas pose several problems in undertaking adequate surveys of the terrain and geo-engineering factors required for route design purposes. Conventional methods are more time consuming and expensive for the extraction of surface profile information required for road alignment. Visualizing the whole terrain at a time using a topographic map from different perspectives is not possible. For the present study, it is proposed to identify a route alignment between Uttarkashi and Kedarnath in Uttaranchal State. At present three routes existing between them, these routes are covering the distance of 260km, 263km and 301km. By proposing a direct route between Uttarkashi and Kedarnath the distance shall be reduced which is expected to be more beneficial to the community, tourism industry and improving urban amenities in hilly areas. In this study GIS has been used as a cost effective tool for the identification of optimum route alignment. The input parameters considered in raster form are land use, soil, slope, geology, aspect and drainage and elevation data. IRS1C LISS-III and PAN Data has been used for land use map preparation. The weights are calculated for each parameter using AHP method, Thematic cost map was generated by adding individual weighted parameters in raster calculator, and cost weighted function is used for identifying the optimum route between origin and destination point.