A stop area is set in an arbitrary area where map matching processing is
to be stopped, by an operation switch group or a remote controller. When
a vehicle enters the stop area, the map matching processing is stopped,
and when the vehicle exits from the stop area, the map matching
processing is performed. It is supposed that a situation where the map
matching processing should be performed has changed to a situation where
the map matching processing should be stopped or vice versa. Here, since
the stop area can be set in advance, it is not necessary to perform any
selection operation. Thus, load on a driver during driving the vehicle
can be reduced.