A system for storing, maintaining, and retrieving location information. One technique is to locate a specific position with respect to a known point. While spatial features are typically located using planar (two-dimensional) referencing systems like geographic coordinates, many transportation features—roads, bridges, and other structures—are located using linear (one-dimensional) referencing systems including the route-milepost system. A linear reference system cannot entirely replace a planar referencing system for geographic display. However, it does represent the format in which most transportation infrastructure data are currently stored and reported.