Study On The Method Of The Estimation Of The Network Capacity Of The Express Freight Transportation System In Intermodal Transportation System

There exists a closed relationship between economy development and freight transportation.A good intermodal transportation network is necessary for freight activities to be carried out effectively.At present,China's economy is in a stage of rapid development,year-on-year increasing demand for freight transport has led to China's transport capacity often being in a tense condition.Therefore,the state attaches great importance to investment in transport infrastructure.However,investment in transport infrastructure is often huge,so it is necessary for the decision-maker to estimate the capacity of the transport network and carry out transportation demand and supply analysis before investment and then to make an effective investment strategy.Because of the complexity of the intermodal freight transportation system,there are few researches on its capacity calculation.The calculation of the network capacity of the intermodal freight transportation system is not only useful for the planning department to make a correct decision to improve the transportation network,but also is useful for the transportation sector to allocate the transportation resources reasonably. Therefore,the research on the method of estimation of the network capacity of an intermodal freight transportation system has a great significance both theoretically and practically.In this thesis,on the basis of review on the existing research of transport capacity at home and abroad,the method of estimation of network capacity of an intermodal express freight transportation system was researched.Firstly,it analyzed the transportation demand and supply and its relationship with transportation capacity,built up the concept system of the intermodal express freight transportation system capacity, discussed the characteristics of network capacity and the significance of the concept system,and used the concept system to explain the tense status of China's transportation capacity.Secondly,it gave the method of calculation of the network capacity of the intermodal express freight transportation system,focused on the calculation of the practical-effective capacity of the intermodal express freight transportation system, discussed the factors that affected the practical-effective capacity,built up a bi-level programming model to calculate it,gave the algorithm to solve it based on GA,and designed an example to verify the correctness of the model and the effectiveness of the algorithm.Finally,it summed up this research,pointed out the deficiencies of this research and gave the problems that need further research.