The routing isn't used so much for routing, more of a pointer to where one is going. Lannon is small enough to easily figure it out (~2.5 sq miles), but we cover Menomonee Falls also for another ~10 miles. The bad part is Menomonee Falls addresses can not be resolved, the DB contains the GPS coordinates for them.
Here are some graphics
In use:
http://www.lannonfire.com/images/Misc/Sample1.gif
Area (yellow is routable, grey is not):
http://www.lannonfire.com/images/Misc/LFD_Area.gif
Mike Mueller