Research On Express Transportation Mode Selection And Routing Optimization Based On Generalized Cost

In recent years,the express industry in China has been developing rapidly,and the express business demand is blooming.Meanwhile,the competition direction of the express market has also changed dramatically.The rapidity and economy have become the core of the competition among express enterprises.With the participation of the normal-speed railway,the high-speed railway and other resources,express enterprises are confronted with intricate choices when making transportation decisions.The study of express transportation modes selection and routing optimization will help enterprises to efficiently integrate and reasonably distribute all kinds of transportation resources,which will provide prospective reference for future express transportation decisions.Firstly,this paper reviews the domestic and overseas research of express transportation modes selection and routing optimization.Secondly,it combs the theory and method of transportation modes selection,express network and express transportation routing optimization,which lays a theoretical foundation for the follow-up research.Thirdly,based on the perspective of enterprises,the mechanism of transportation modes selection is analyzed in depth.And from the demands of different express products,this paper analyzes and quantifies the influencing factors of express transportation modes selection,then constructs generalized cost function and Logit Model of express transportation modes selection.Fourthly,in order to fit the actual situation of express transportation,PCA Model is used to research the hub-and-spoke network nodes programming.Therefore,the hub-continuous routing optimization problem is transformed into the hub-discrete routing optimization problem.On this basis,the relevant assumptions of the express transportation routing optimization are proposed,the express transportation routing optimization model is constructed and corresponding partheno-genetic algorithm is designed.Finally,conducting an empirical analysis based on the relevant data of SF-Express.The empirical results of express transportation mode selsction show that different express products have different rapidity and economic demands,and different transportation modes are suitable for different express products.The aviation is suitable for the extra-long distance transportation of timeliness products.The high-speed railway is suitable for the long distance transportation of the timeliness products.The normal-speed railway is suitable for the large-scale transportation of timeliness products.And the road is suitable for short distance transportation of timeliness products and the transportation of w\eak timeliness products.The result of routing optimization shows that routing optimization can reduce the general cost of express transportation,realize the scale economy of express network and improve the rapidity and economy of express transportation.