Travel time prediction using speed profiles for road network of Croatia

Prediction of travel time through the road network has a important part in traffic management systems and traveler information systems. Compared to the currently used constant speeds along the roads in Croatia, the speed profiles provide the information about time dependent speeds along the roads and increase the accuracy in travel time predictions. This way the overall costs of transportation can be reduced in both logistics and every day transportation. In this paper the processing of speed profiles for use in time dependent shortest path algorithm is performed which includes clustering, smoothing and first-in-first-out (FIFO) property analysis. The travel time predictions using different sets of speed profiles, dependent on cluster size and seasons, are compared to the real measured travel times. The results show the overall increase in accuracy of travel time prediction using speed profiles compared to constant speeds along the roads by at least 10 %.