本文研究协同运输的路线整合问题(CTRIP):允许所有的O-D流(运输任务)在规定的路线长度内任意采取直通运输、单点中转、两点中转的整合运输路线,整合运输的中枢路段在支付固定成本后可产生运费折扣,如何选择O-D流的整合路线使得总成本最小?CTRIP广泛应用于航空、物流、快递等领域的整合运输实践。论文构造了CTRIP的混合整数规划模型和Benders分解算法,实验显示,算法表现出非常好的计算绩效。最后,我们利用一个具体实例对CTRIP与已有研究展开了比较,结论显示CTRIP更能保证中枢路段的规模优势。
Collaborative transportation is a good way of saving logistics costs by integrating all transportation demands and transportation resources to achieve economies of scale.Under the scale effect,the unit transport cost is lower if we construct a hub arc by paying a fixed charge and take more flow to the arc.And transportation tasks have to carefully choose their route since zigzag route has larger distance than direct route.In this paper,collaborative transportation routing integration problem are studied with fixed arc costs and distance limitation(CTRIP),which seeks the optimal transportation route of all O-D flow to minimize the total costs including routing costs of tasks and fixed costs of hub arcs,while the routing distance is required to be within a limited range.CTRIP arises in the application on airline transportation,road transportation,postal services and pipeline transport.A mixed-integer programming model is formulated for CTRIP,and a heuristic algorithm is provided based on Benders Decomposition.Then,a computational experiment is carried out based on AP data set from OR-Library,and the results show the algorithm works well.Further,CTRIP is compared with current relative researches about Hub-and-Spoke Network Design Problem(HASNDP)on a special instance.It is found that CTRIP can better guarantee scale advantages of hub arcs than CTRIP which has a flaw hypothesis.Unlike HASNDP which concentrate on integrating tasks through hubs,combing transport through hub arcs is the focus of this paper.The study can provide a new perspective research about collaborative transportation by shifting our method from integrating tasks through nodes to combing transport through arcs.