Dynamic Traffic Flow Analysis And Expression Based On GPS Technology

The paper proposed two technology used in dynamic traffic flow analysis and expression. As a part of Intelligence Transportation System and based on dynamic traffic information, traffic flow analysis could achieve automatic, real time traffic status analysis, bring convenience for both traffic control department and vehicle navigation systems.GIS(Geographic Information System) Traffic flow analysis based on GPS(Global Positioning System) technology, is a technology which uses satellite navigation technology, conducts intelligence analysis and expresses the traffic status on the GIS system. It helps raising the utilization rate and has great affect on solving the traffic problem brought by rapid development of the city.This paper first describes relative theory about Geometric Information System, introduces a practical construction process of the digital map in it, and gives the development of our GIS system as an example.Then, we introduced the principal and application of GPS and give out a method of transforming GPS coordinate to GIS coordinate. We describe the experiment result and then proposed an advanced transforming method used in our system.Then, we introduced a real time analysis system based on GPS technology and the GIS system we have previously designed. It consists mainly of three parts: coordinates transformation, map matching and data fitting. Through this process, we get the velocity distribution on certain road, and then realize the estimation of urban traffic flow for the whole Shanghai road network.