SETTING UP A ROAD NETWORK
Unfortunately, you cannot expect the network to be fully prepared for you every time you do a network analysis. There’s a lot of work behind the scenes before you can actually perform a network analysis. This includes setting the travel cost for each arc, defining directions and one-way streets, managing restricted turns and most important, address matching.
First, add the nonetwork road theme to your view. The roads look the same as before, but they lack much of the necessary network information.
You can still perform a network analysis with just this line theme present. However, the default cost then is equal to distance traveled. There are no directional restrictions (you may go the wrong way down a one way street, or use the wrong side on the freeway, and turn wherever you want). Routing by address is also more difficult, albeit possible, since you can always select your stops graphically at the approximate position, if you have enough local knowledge to know where you are in the view.
