AbstractWith the intensifying competition of the fast freight market, thetransport network that enterprises depended on for existence has already becomethe key points to transportation efficiency and the service level, so thequality of express network routing is particularly important. This paperfirstly focuses on the hub-and-spoke network structure, and puts forward ahybrid hub-and-spoke network with stopovers structure and several constraints;then, the paper introduces a (0,1) optimization mathematics model, that isbased on a improved saving matrix method, which can be solved by Lingo softwareprogramming; a practical application to Guangzhou region of a road expresscompany is also described ;at last, the paper compares several differentresults when constraints change.

Keywords hybrid hub-and-spoke network, routing planning, 0-1non-linear models, improved saving matrix method

1 Introduction

The freighttransportation is fast growing in our country in recent years, the competitionwhich the freight transportation enterprises face is fiercer and fiercer at thesame time, lower costs and improve the enterprise's competitiveness become vital.The hub-and-spoke network can combine logistics resources, improve theresources utilization efficiency of the logistics, reduce the cost networkstructure of the logistics effectively. The hub-and-spoke network is used inair lines’ design in initial stage [1]. In recent years, hub-and-spoke networkwas applied in transportation field, but most research focus on hub locationproblem rather than on routing planning [2]. It’s hard to find that specializedresearch in hub-and-spoke road express network routing planning [3]. This paperis on the basis of considering the hub-and-spoke network structurecharacteristic and express network operation mode synthetically, has putforward the hybrid hub-and-spoke type network with stopovers, has set up aplanning model based on the shortest network mileage, has solve the model usingan improved saving matrix method, thus develops express network routingplanning researches.

2  Hub-and-Spoke Road Express Network

2.1Network structure

The hub-and-spoketransport network regards a certain logistics site as the hub and its frameworklike the wheels [4]. As shown in Figure.1, there are certain amounts of transitnodes (i.e. hubs) in the network, each hub radiates several littletransportation nodes (i.e. spokes). We refer to a hub and a lot of subordinatespokes as a large region. No matter goods transport in or between the regionmust go through the hubs, this can amalgamate freight volumes in the hubs, thusrealize the economical benefits of the scale. 

Observing Figure.1,we can find each spoke links up with the hubs directly, that is everytransportation circuit does not allow stop on the way. The shortcoming of thiskind of network structure is the extension of the distance of freighttransportation, which makes service time increase correspondingly and hasreduced customer's service level. As shown in Figure.2, this paper proposes ahybrid hub-and-spoke road express network with stopovers. To some two or morenodes which have few goods amount or with close geographical position, thiskind of structure concentrates the goods to the spoke node closest to hub nodesequentially. Then goods are transported to the hub and the destination. Thischange of network structure makes the total mileage of network reduce, theservice level improved, the number of routes reduced at the same time, thus tomake the network optimized.