Note that I am a complete novice to ArcGIS. I am a student and am using the software to complete a project. I have a basic shape file of bus routes that I am trying to convert to a network so that I can carry out a journey time analysis. Included with each route profile is an average journey time in minutes, which makes it possible to calculate an average speed for each route. When I attempt generate a road network shapefile from the basic file I think I must be making an error, as when I import the newly created file into ArcMap, Network Analyst remains blanked out. What steps must I carry out to convert the shapefile into a usable network in ArcMap?