PURPOSE: To effectively utilize a track obtained by the preceding traveling and to improve the travel guide function of a device by providing the device with a current traveling position measuring means, a road map storing means, a traveling track displaying means, a traveling track registering means, a redisplay track displaying means or the like.

CONSTITUTION: The current traveling position of a vehicle is measured by the current traveling position measuring means 2, displayed on the traveling track display means 6 together with information relating to a road map stored in the road map storing means 4 and then registered in the traveling track registering means 8. At the time of specifying the traveling track registered in the means 8 by the input of operation, the traveling track is read out through the redisplay track selecting means 10 or the like and displayed on the means 6. Since the registration of the traveling track and its optional selection and display can be attained through the means 8, 10 or the like, the past traveling route can be optionally selected and traced or a byroad or the like which is not written on the display map is newly registered to form an original road map. Thus, the registered traveling track can be effectively utilized and the travel guide function and convenience of the device can be improved.