Determining highway slope ratio using a method based on slope angle calculation

Geographic Information System (GIS) is a vital tool used in numerous areas related to natural science and engineering studies. Managing complex data obtaining accurate results from the analysis are essential functions of GIS. It also efficiently highway designing both project application phases. This study proposes new calculation method slope angles determine suitable modal road by using topographic geological datasets GIS environment. Using this preparation phase enables more earthwork volume. The proposed was applied prove idea. selected significant tertiary which completed Turkish General Directorate Highways. In study, calculated values were considered as references. Comparing obtained project, accuracy 71%, its volume 99%. approach will enable managers designers reliable during feasibility studies without any field.