Research On Express Freight Trains Operation Plan Based On Delivery Time Limitation

With the rapid development of China's economy and the continuous adjustment of industrial structure,freight market is also undergoing tremendous changes in China.The transportation demand of traditional bulk goods has been greatly reduced,while the high value-added goods characterized by "small volume","multi batch" have been growing rapidly in recent years,which have higher requirements for transportation efficiency and safety.In order to meet the market demand,the Railway Corporation carried out the freight organization reform,organized and launched a variety of express freight transportation products,such as high-speed rail express,freight express trains,etc.,but due to various reasons,it is still unable to compete with the highway and air transportation enterprises,which leads to the low market share of the current railway transportation enterprises,so it is necessary to launch a new type of railway freight products to recover market share.At present,domestic scholars have done a lot of research on the optimization of express freight train operation plan,and the research results have been quite mature.In the model,the objective function takes the lowest cost and the biggest profit as the optimization objective,which plays an important role in the adjustment and optimization of express train operation plan.But generally speaking,in the current research,when designing the express train operation plan,the main consideration is the revenue of railway transportation enterprises,and less consideration is given to the differential demand of cargo owners,especially the delivery time.Therefore,it is of great significance to establish a set of operation plan based on the delivery time effective express train to meet the market demand.Based on the current market situation,this paper studies the express freight trains operation plan based on the delivery time limitation.First of all,this paper analyzes the current demand situation freight market in China,expounds the category of express freight from a narrow sense,and discusses the demand characteristics of express freight transportation,so as to draw the deficiencies of the current supply of express freight transportation products.At the same time,combined with the current situation of railway transportation equipment in China,the feasibility of freight train operation is analyzed from three aspects of economy,policy and technology.Based on the analysis of the development status of express freight transportation in China,this paper puts forward the optimization and improvement method of the transportation organization mode according to the characteristics of the operation of the express freight train based on delivery time limitation,and discusses its transportation process.Then,the paper discusses the theory of the establishment of the express freight train operation plan based on the delivery time limitation,and analyzes the contents,influencing factors andprinciples of the establishment.According to the different levels of service prescription,the express train can be divided into same day delivery,next morning delivery,next day delivery,2-day delivery.Based on the analysis of the operation process of express trains,the longest running time and the longest service radius of different classes of trains are obtained.Then,the first,second and third level nodes are determined by qualitative and quantitative analysis methods,and the express freight transportation service network is constructed based on the existing railway transportation network in China.Based on the step-by-step optimization of the operation section,the number of groups and the service frequency,a multi-objective programming model is constructed,which takes the maximization of transportation revenue and the minimization of transportation cost as the objective function.In the model,the number of groups and service frequency of express freight train can not reach the maximum at the same time to optimize the market demand and the economic performance of railway transportation enterprises.Finally,through the design of an example,the optimal operation plan is obtained and evaluated,which verifies the feasibility of the operation plan of express freight train based on the delivery time limitation.