Where I live, there are quite a few "unimproved" roads that have been "improved" and are either newly-paved or still unpaved due to development in the area. So there are gaps in my Nav system because either these roads were not there at the time the car was made, or new side roads have been constructed off thoroughfares that previously existed. The last time I used Nav around here, there were places I would have turned to get to the destination more directly but the system didn't have them in its database.