Research On The Scheme Design Of Combined Transport By Road And Rail Of Transportation Of High Efficiency Goods Based On Hypernetwork

In recent years,with the rapid development of e-commerce in China,the transportation demand of high timeliness and high value-added goods represented by seafood,drugs,flowers,auto parts,etc.is gradually increasing.High efficiency goods often have strict requirements on transportation capacity,transportation speed and transportation conditions.Although the traditional road transportation can realize "door-to-door" transportation,it is mainly for short and medium distance transportation.For the case of a long distance between the city of origin and destination,the cost of highway transportation is often high,but the effect is very little.In serious cases,the goods may arrive late and lose their value.The characteristics of the high-speed rail,such as rapidity and safety,can well meet the transportation needs of high timeliness goods.Based on this,this paper combines the timeliness of high-speed rail transportation with the flexibility of road transportation,and uses the hypernetwork theory to construct the network of existing high-speed rail stations,lines and road freight source city nodes in the whole country,to identify the important high-speed rail stations and lines in the network.Considering the factors of time,loading difference and freight volume,this paper designs the integrated highway and railway transport scheme,and studies the freight share of high-speed rail in this case,so as to provide a reference for the future planning of high-speed rail freight trains in China.The main work of this paper is as follows:(1)Taking the existing 774 high-speed rail stations as nodes and 3740 high-speed rail lines as hyperedge,the high-speed rail hypernetwork is constructed;339 freight source cities are selected as highway nodes,if there is a highway distance between the two cities,the number of highway lines is 1,and the highway hypernetwork is constructed;the cities where774 high-speed rail stations are located are matched with 339 freight source cities,and the transshipment hyperedge is constructed.After data matching,723 high-speed rail stations and223 highway nodes are matched,with a total of 723 transshipment hyperedges,thus constructing the transshipment hypernetwork.By connecting the three networks through the transshipment hyperedge in the transshipment hypernetwork,a simple non-weighted hypernetwork of road-rail combined transport is constructed.(2)Six hypernetwork topological parameters,including node degree,node overrun degree,edge overrun degree,hyperedge degree,average path length and aggregation coefficient,are selected to measure and compare the high speed rail hypernetwork and the hypernetwork of road-rail combined transport.The results show that the overall performance of the hypernetwork of road-rail combined transport is better than that of the high-speed rail hypernetwork,and the key stations and routes in the hypernetwork are comprehensively analyzed by using various indicators,which provides the basis for the opening of the high-speed rail freight trains in the future.(3)Based on the hypernetwork of road-rail combined transport,combined with the data of high-speed railway timetable,highway freight distance and average speed of highway freight cars,the time weighting is carried out,in which the transit time is obtained by averaging the transit time of a large number of waybill data of high time effective goods.The time cost function is constructed to plan the high efficiency goods distribution scheme among339 cities in China.Then,considering the differences of freight volume and loading,the freight sharing rate of the whole hypernetwork under the corresponding path of minimum time cost is studied.