A navigation apparatus defines the route of movement from the current location
to the destination on the basis of map information. It acquires road information
relating to characteristics of the current road on which the vehicle is running
and those of each of the branch roads extending from the fork located ahead of
the current road by way of road information acquiring section 21. The acquired
road information is collated with the requirement information stored in requirement
information storage section 22 and the number of points correlated with
the requirement that is met or not met are added or subtracted, whichever appropriate,
to determine the total number of points by the agreement judging section 23.
If the total number of points is greater than a threshold value, the navigation
apparatus judges that the vehicle may not divert from the route of movement and
restricts or suppresses guidance for driving the vehicle provided by guidance notification
section 18. If, on the other hand, the total number of points is smaller
than the threshold value, the navigation apparatus judges that the vehicle may
divert from the route of movement and allows the guidance notification section
18 to provide guidance.
