Differential dynamic navigation system for off-board car navigation

An off-board navigation system for providing navigation and route information including real-time information comprising at least one client and a server, said at least one client being connected to said server via a wireless connection. The off-board navigation system comprises a static map database for storing road map data and a traffic information database for storing traffic information data, wherein said databases are connected via a telecommunication or computer network to said server for providing said client with navigation and road map information, characterized by a dynamic map database for storing time varying attributes of said road map data under consideration of said stored traffic information data. The present invention therefore offers the advantages that changes of traffic information data can be easily identified and traffic incidents affecting the optimal route are continuously monitored even if the user is using an alternative route.