Abstract: A method for calculating a distance between a first point and a second point using linear interpolation is provided. The first point and the second point are located between a first latitude and a second latitude. An interpolated prime vertical radius of curvature value for a point between the first point and the second point is calculated based on a first prime vertical radius of curvature value for the first latitude and a second prime vertical radius of curvature value for the second latitude. An interpolated meridian radius of curvature value for the point between the first point and the second point is calculated based on a first meridian radius of curvature value for the first latitude and a second meridian radius of curvature value for the second latitude. An interpolated cosine value for the point between the first point and the second point is calculated based on a value representing a cosine of the first latitude and a value representing a cosine of the second latitude.

Abstract: An architecture for a geographic database that supports the identification and use of names for intersections of roads located in a geographic region, and methods for use and formation thereof. The geographic database includes data that represent components of a road network in a geographic region. The geographic database includes a first plurality of data entities each of which represents an intersection of roads in the road network and a second plurality of data entities each of which represents a name of one of the components of the road network. The geographic database includes a third plurality of data entities each of which associates one of the first plurality of data entities with one of the second plurality of data entities.