Travel times as a basic part of the LISB guidance strategy

The Berlin LISB Guidance and Information system is an individual, dynamic guidance system for motorised vehicles. LISB works in accordance with the principle of central route searching. Within a cycle of a few minutes, a computer in the traffic control centre of the road transport authorities calculates and offers the quickest routes for any given O-D relation in the entire urban area. The vehicle transmits to the beacon the travel and queueing times which it has gained from the network since it passed the last beacon; it then receives information about the quickest route to all surrounding beacons as well as the allocation of these routes to the destination coordinates. Thus, the navigation device can select the links by which the vehicle finds its destination. Over the day, travel times vary with the traffic volumes on the links of the network. Therefore a recommendation of quickest routes must not be static. The authors consider the role of travel time prediction and the methods for measuring times for the guidance system