1. Field of the Invention
The invention is directed to a process for the transmission of route information concerning a route of a vehicle in a traffic network between a central traffic station and a terminal unit in a vehicle, a central traffic station, and a terminal unit.
2. Discussion of the Prior Art
A central traffic station can prepare traffic status reports, traffic forecasts and traffic navigation aids for a terminal unit from information obtained from stationary detectors in a traffic network and obtained from mobile detectors (in vehicles FCD) and transmitted to the central traffic station. For the transmission of obtained traffic information from a vehicle (via mobile radio, etc.) to a central traffic station as well as for the transmission of information about traffic status reports, traffic forecasts, traffic navigation aids, etc. from a central station (via mobile radio, etc) to a terminal unit, it is required to designate each location to which a piece of information refers. When there is an identical map in the terminal unit and in the central station, location referencing with respect to the map is possible; however, maps are constantly being updated because of new roads, changes in driving direction, detours, construction sites, etc., so that different map versions may exist in the terminal unit and in the central station. A problem in location referencing based exclusively on geographic longitude and latitude consists in the required allocation to a road in a map; in particular, for example, there may be no road at a measured location position of a terminal unit in the map in the central station or no road in the map terminal unit at a geographic location position in the map which is referenced by a central traffic station. The use of shared reference tables for locations in a traffic network is limited with respect to the degree of detail because of limited available storage capacity. Such processes are accordingly suitable only to a limited extent for the transmission of information within the framework of a navigation service which is also especially advisable in remote areas.