Patent ID: 6487497
Filing Date: 2002-11-26
Classification: G01C

Abstract:
In a route calculation program, a computer readable locus data structure means for use with a map database, wherein the map database includes a plurality of data records representing road segments in a geographic region, wherein said computer readable locus data structure means identifies a location along one of said road segments, said computer readable locus data structure means comprising:a first portion that identifies one of said road segments along which the location can be accessed; a second portion that identifies a subsegment of the road segnent identified in said first portion, wherein said subsegment corresponds to a position between endpoints of the road segment identified in the first portion via which the location can be accessed in a desired direction; and a third portion that identifies a side of the road segment identified in said first portion, wherein said side corresponds to a side of the road segment identified in said first portion via which the location can be accessed at the subsegment represented by the second portion.