To solve the problem where position correction data cannot be surely received and hence a current position cannot be corrected since an FM broadcasting station with improved reception conditions is selected and the position correction data cannot be received, even if a plurality of FM broadcasting stations are broadcasting position correction data although both the position correction data and road traffic information by VICS can be received.

A DGPS station, located at the shortest distance from a current position, is selected from among a plurality of DGPS stations for transmitting position correction data, and the position correction data is received from the DGPS station.