Abstract
Dynamic navigation systems can substantially benefit from reliable real-time urban traffic information. In this paper a method is shown that calculates the current urban traffic state based on probe vehicle data from fleet vehicles. On all links where there is no information present, historicaltraffic data is used. The calculated velocity information is integrated into the dynamic on-board navigation system. In contrast to other routing solutions this method not only informs the driver about traffic congestion and dense traffic, but also about currently free-flowing traffic. The authors conclude by comparing the probe vehicle data approach to existing car-2-car based traffic information systems.