(Data West Research Agency definition: see
GIS glossary.) The database designed and prepared for Intelligent Vehicle Highway Systems to support such systems for "smart cars" and "smart highways." These databases contain first the geometry element layer of the roadway that contains links, nodes, shape points, relative elevations, and connectivity. The second navigation element layer contains physical and logical classification of the roadway environment, directionality, dividers, barriers, turn restrictions, freeway exit numbers, and exact freeway sign text speed limits, and others. Additional element layers include points-of-interest, path, geopolitical, cartography, geocoding, and special commercial/business listings.