Comparative benefits of various automotive navigation and routing technologies

The first practical in-vehicle automotive navigation systems utilized dead reckoning combined with digital map-matching to keep track of vehicle positions and to show them in real time on digital map displays. Global Positioning Satellites (GPS) and differential GPS have provided significant navigation system improvements when combined with dead-reckoning, and they have enabled alternative navigation systems that operate without dead reckoning. The introduction of map databases with accurate connectivity, directionality, and turn-restriction attributes have permitted automatic computation of optimum routes as well as presentation of turn-by-turn route-guidance instructions for driving those routes. This paper looks at advantages and limitations of various automobile location and routing techniques, and discusses how limitations can be overcome by combining techniques. Trade-offs between features, performance, and cost are also presented for some specific implementations.