The use of telematics to monitor traffic in urban areas: Theory and Applications

To alleviate urban congestion, macroscopic feedback control strategies have recently introduced which rely on real-time observation of relevant spatially aggregated measures of traffic performance. Ample monitoring of the system is necessary for those strategies to be successfully implemented. An efficient and practical methodology is developed to estimate the fraction of vehicles in a city that should be tracked. A filter to identify passenger-carrying taxis based on GPS data is described. An application in a real city and comparison with detector data show that the average speed can be predicted quite accurately.