Vehicle Probes as Data Collectors for Asian Metropolitan Areas

Starting with Ningbo, China, where a system of taxis equipped with satellite positioning systems and mobile communication was established, vehicle probe data collection techniques are presented for Asian metropolitan areas. The aim is to generate an online traffic situation report. The system’s architecture consists of a positioning/navigation unit and a radio link to a dispatching center. From the dispatching center, a server is supplied generating a database for link travel times and specific data evaluation. First experiences are reported for data collection and data processing for online traffic control and dynamic route guidance. The cornerstone of the technique is a digital map that can be generated in a first approach from recorded positioning data of the taxi fleet. The process of map generation and feature attachment is presented together with an analysis of hot spots and critical sections. The approach is embedded in new developments for air borne and space born data detection and control technologies. These future technologies allow the establishment of traffic control systems without much infrastructure for data detection and are perfectly suited for the emerging and fast growing metropolitan areas in China’s east. The satellite borne recording technique can be extended to road infrastructures inventory and the vehicle probe technique can be used for transportation planning purposes, as well. The database can be used for deriving performance indices of the metropolitan areas’ vehicular traffic. Travel time analysis and mean speed time series recording anticipates the formation of critical regions and traffic hot spots. The online information helps not only for traffic control with corridor control systems and traffic signal control but also for incident management and patrol service optimization.