The Research Of Logistic Park's Dynamic Traffic Assignment

For a long time, people pay more attention to urban dynamic traffic assignment, but seldom to the dynamic traffic assignment in logistic park and the information which is available on the relatively is small. Logistics Park's main flow of traffic is freight, and the transport flow mode is affected by freight system. Meanwhile, it can also cause traffic jams and environment damage in Logistics Park. Almost all the park logistics are dependent on different modes of vehicle, so the road network traffic conditions affect the operation of the logistics park. Therefore, the dynamic traffic flow model is very important to the simulation of the park logistics. It provides important safeguards of improving the; operational mechanisms in the park, makes the material in logistics park reach the real sense of the effective and smooth flow, and makes the value of goods space conversion and integration within the limited resources of the park better achieved. This paper not only summarized the current researches on dynamic traffic assignment problems, but also described the equivalent relation between the variational inequality model and the dynamic user- optimal condition in detail. Based on the research of improved Greenshields Speed - Relational Model of the logistics park DUO assignment, it analyzed this mode and analyzed the main factor affecting of the Model, then discarded the original static model of the impedance function BPR. It also illuminated necessity of the method of variational inequalities in the assignment of dynamic optimal application transport the inevitable, gives projection algorithm and improved ant colony algorithm by the characteristics of model, which are used to solve the logistics park's dynamic traffic assignment problems, and search for the best algorithm through data validation. Finally, put the optimal distribution of dynamic user variational inequalities model into the actual project to carry through the emulational analysis, and discussed the existence of several major current issues and further development prospects.