Dynamic Route Guidance - Status and Trends

Most of the existing car navigation systems are operat-ing autonomously using a static digital road map on-board. The benefit of such systems lies mainly in trips through un-known street networks. Systems providing routes dynamically adapted to the traffic situation ease driving even in well-known areas. Two principles can be used for dynamic route guidance. One is receiving the description of a complete recommended route from a traffic center. The other one is just receiving encoded traffic messages for updating a static map according to the traffic situation. In the first case, route calculation has to be performed centrally by the service provider, while the second method needs the on-board route calculation. Both methods have advantages and disad-vantages and need a method to refer to their local street map. The status of such systems and trends are described.