A car navigation apparatus includes: a current position detection device that
detects
a current position of a vehicle; and a control device that detects a plurality
of roads as candidates used for map matching based upon road map information containing
road data used for navigation of the vehicle and the current position detected
by the current position detection device, and execute map matching with a most
appropriate road among the plurality of roads, and the control device does not
execute map matching when a road among the plurality of roads as the candidates
used for the map matching is judged to form a circular crossroad.