Geographic database architecture for representation of named intersections and complex intersections and methods for formation thereof and use in a navigation application program

A method of using names for intersections using a navigation application program, wherein the names for intersections are represented by data records in a geographic database stored on a computer readable medium, wherein the geographic database represents a road network of a geographic region, wherein the method comprises the steps of:

• providing data records in said geographic database specifying names for navigable features including roads and intersections of said road network;
• providing data records in said geographic database specifying road segments of said road network and intersections of said road segments;
• and
• providing data records in said geographic database representing named intersections, wherein each of said data records representing named intersections associates one of said data records specifying names for navigable features with one of said data records specifying intersections of road segments.

A geographic database architecture for use with a navigation application program that provides navigation features to an end user wherein the geographic database includes a plurality of data entities that represent geographic features in a geographic region, said geographic database architecture comprising:

• route calculation data comprised of a plurality of segment data records and a plurality of node data records, wherein each segment data record represents a portion of a road in said geographic region and each node data record represents an end point of a portion of a road, and wherein said route calculation data include attributes which include the routing characteristics of the portions of roads represented thereby and intersections thereof;
• navigation feature data comprised of a plurality of data records each of which represents a name of a geographic feature;
• and
• junction data comprised of a plurality of data records each of which relates one of said node data records with one of said data records of said navigation feature data.

A method of operating a navigation system to provide route guidance for a route wherein the route is comprised of a list of data records in a geographic database and wherein the data records represent navigable geographic features along the route, the method comprising the steps of:

• examining data that represents an intersection along said route to determine whether the data includes an indication that the intersection represented thereby is named;
• for each of said data that includes said indication, using an index into a list of names for navigable features to ascertain a name for said intersection;
• and
• explicating said name.

The method of claim 29 further comprising the steps of:

• for each of said second groups, prior to identifying all the navigable paths between each of the road segments,
• defining a geographic area that encompasses the features represented by the records of the first group included in the second group;
• identifying a third group of data records, wherein said third group comprises data records in said geographic database that represent features including in said defined geographic area in addition to those represented by data records of said first group included in said second group;
• augmenting said first group of data records included said second group to include said third group of data records when identifying all the navigable paths through the complex intersection.