Study On The Methods Of Congestion Identification For Urban Roads Based On Probe Vehicles System

For the purpose of dealing with the rapid growth of traffic demand, disseminating traffic information and coordinating traffic signal control become important methods of improving the efficiency of urban road network. However, both of the AITS and Traffic Control requires high precision and real time traffic data. Probe Vehicle system is the latest real-time traffic condition detecting tool, which provides a new method of real time data collection.This paper was based on the latest reseach of probe vechicles system and mainly solved the problem of detecting the sub-level of traffic conditions which is a traffic jam early warning status. The link travel time and queue length estimation models were established and the reliability was discussed. After simulation analysis we can conclude that the proposed detecting method has good reliability and its performance is better than the traditional method. Further more, the proposed algorithoms are fitable for small sample-size estimation.Based on the estimation method of these two parameters, this paper finally complete the traffic conditon level detecting model. The analysis for simulation data by this model shows that this model can detect different level of traffic conditions effectively.At last, the conclusions and future researches are proposed.