a method and device for generating , merging and updating data for use in a destination tracking system which comprises , among others , the following steps : generation of data by mobile units to model reality concerning route and traffic , and storing this data for further use . a highly up - to - date and extremely reliable database is built - up in a simple and efficient way by merging data from many units . this database makes it possible to answer a number of complex problems , for example , about the passable route network and realizable travel times . on input of an origin and a destination node together with the intended travel time , destination tracking data is calculated from the stored data . since the origin - destination relationships of the motions carried out by the mobile units in dependency of all conceivable parameters are known , the destination tracking recommendations for each individual participant can be given such that the sum of the times of movement of all participants is minimized .