Method for obtaining average speed of city rode traffic low region

Based on considering each error existed in data received by GPS, features of roads in GIS, and artificial factors of drivers synthetically, the invention uses a method of nearest neighbor to obtain preliminary matched result in map. Accurate positioning location of vehicle is obtained from following steps: through A* algorithm finds out shortcut between two points; recovering run locus of vehicle in real time and intelligence; considering relation between fore and after as well as load condition of data of vehicle, the method carries out modification for doubtful matching points and formed run locus of vehicle. Finally, average up going speed, down going speed and average speed in mixed-use area are calculated from run locus of vehicle, and displayed on digital map. Features are: high real time and precision, without need of angular transducer etc. hardware facilities so as to lower system cost and complexity of designing system, and raising system performance