Application of dynamic traffic flow map by using real time GPS data equipped vehicles

Dynamic traffic flow map is one of the focuses of recent researches on ITS, but it is limited by the locations and numbers of traffic detectors. This paper presents a method for traffic flow map using the data received from the GPS mobile terminals equipped vehicles. Firstly, a vehicle real-time monitoring GPS system is given. Secondly, a map-matching method was proposed, which eliminated ineffective data by observing the vehicles status and calculated link time cost of each probe vehicle and the average speed. The equation of speed-flow relationship established by observing traffic data, especially the general one established in conditions of any traffic roads under any traffic burden conditions. Thirdly, it developed a dynamic traffic flow map arithmetic based on the results above and successfully solved the questions: data collecting, traffic barrier-free conditions processing and traffic flow map calculating. Finally, the results of simulation experiment indicate that the methods are effective and practical. It can be used as a new real-time network method to control the traffic signal, which is different from the traffic signal controlled method that depends on the timer or road linear controller method.