Using a DEM, I need to assign slope to individual segments in a street centerline feature class. It will be used to account for increased travel time for steep slopes in a network analysis. I am using ArcGIS 10.0, ArcInfo license, with 3D Analyst and Spatial Analyst extensions available.
My initial attempt was to use the "Add Surface Information" tool. However, the resulting average slope values seem suspect in some areas, for example if a stream crosses the street segment. I would like to try assigning elevations to street segment endpoints then calculating slope. I have read about this method Calculating average slope along line using ArcGIS Desktop?) but need further details on the process.