Modeling Of Congestion Propagation And Dissipation For Typical Traffic Incidents Based On Kinematic Wave Theory

Facing the expansion of city scale and the acceleration of motorization process in China, many major cities are trapped deeply in troubles caused by traffic congestions. Compared to the recurrent traffic congestion which often occurs during the same periods, accidental traffic congestion caused by traffic incident is more likely to cause disorder phenomenon of road traffic flow. Therefore, in order to implement targeted traffic management strategies, it is necessary to study the propagation and dissipation mechanism of congestion caused by traffic incidents. In this context, by analyzing the characteristics and the key influential factors of congested traffic flow under incident condition, this thesis develops the models of congestion propagation and dissipation for expressways based on kinematic waves theory, and verifies the applicability and accuracy of the model by using typical examples.First, by focusing on the models of traffic flow characteristic parameters, especially macroscopic traffic flow models, the relevant applications of Van Aerde model and kinematic wave model are summarized emphatically. The studies on the characteristics of congestion propagation and dissipation are reviewed and analyzed in different angles and with different methods.Secondly, in order to develop the methodology for determining model structure and data-base for the model application, the state-of-the-art of traffic information collection technologies is summarized, and the acquisition method of basic data is selected. The characteristics and the applicability of the output data are then analyzed, and the method of data processing is described.Further, supported by the basic theory, the formation and transmission of kinematic wave caused by congested traffic flow evolution under traffic incident is analyzed. Meanwhile, the influences to the congested traffic flow parameters caused by capacity decline, arrival and departure of vehicle and other factors are studied. The speed model of congestion propagation and dissipation on expressways under different data conditions is developed. The model is also applied for verification.Finally, based on the characteristics between vehicle arrival and departure, the bottleneck effect caused by changes in traffic demand and capacity under traffic incident is analyzed, different forms of congestion dissipation under traffic incident is classified. Then, the dissipation speed models of congestion for different dissipation types and supported by different data are developed. Typical real incident examples are applied in case study for theoretical analysis and model applications as well.