Patent ID: 7383125

Claim:
A navigation method for determining a position of a street address number, comprising the steps of: receiving a street address number of a destination specified by a user; retrieving data indicating a street segment which includes the specified street address number thereon from a map information storage; searching for supplemental data regarding a place associated with the retrieved street segment including information indicating absolute position of the place and retrieving the supplemental data from the map information storage; defining two or more absolute positions on the street segment with use of the supplemental data and the street segment data; selecting two absolute positions on the street segment that have the specified street address number therebetween; and determining a position of the specified address number by interpolating a length between the two selected absolute positions with a constant interval; said step of defining two or more absolute positions on the street segment includes a step of drawing a reference line perpendicular to the street segment from a selected point of the place showing the absolute position on the place where said reference line is an imaginary line drawn for determining said absolute position.