Patent ID: 8244464

Claim:
A navigation apparatus that collects a trace of a vehicle and has a function to produce an unregistered road data representative of an unregistered road on a basis of the trace and perform registration of the unregistered road data in a map data storage medium when it is determined that the vehicle travels on the unregistered road, wherein the unregistered road is a road that is not stored in the map data storage medium, the navigation apparatus comprising: a turn determination section that determines whether the vehicle makes a turn in direction; a road deviation determination section that, in response to determining by the turn determination section that the vehicle makes the turn in direction, acquires a road width data indicative of a road width of a place where the vehicle makes the turn in direction, and determines based on the road width data and the trace of the vehicle whether, in making the turn in direction, the vehicle is deviated from a registered road by a first threshold or more, wherein the registered road is a road that is stored in the map data storage medium; and an unregistered road data record prohibition section that prohibits the registration of the unregistered road data in the map data storage medium when the road deviation determination section determines that, in marking the turn in direction, the vehicle is deviated from the registered road by less than the first threshold.