Navigation method for motor car, involves determining whether computed route has route section that is not present in digital road map, and requesting navigation information relative to route portion from central device by navigation system

摘要

The method involves storing two digital road maps in a central device (ZE) and a motor car navigation system (NS), respectively. A route is computed by the central device based on one of the digital road maps. Route data describing the computed route is transmitted to the navigation system, and a determination is made by the navigation system to find whether the computed route has a route section that is not present in the other map. Navigation information relative to the route portion is requested from the central device by the navigation system. An independent claim is also included for a motor car navigation system comprising a memory device.