Providing subsidy is a widely-used method by the government to promote the development of sea-rail intermodal transportation.This paper investigates the optimization of coordinated subsidies for sea-rail intermodal transportation in a container freight system including three modes and two departure ports.A bi-level programming model is developed to describe the game relationship between the government and shippers.The upper-level model determines the subsidy amount per heavy container for each train from the government's perspective to maximize the volume of sea-rail intermodal transportation.The lower-level model represents shippers'choice behavior for departure ports and modes under subsidies using the capability constrained nested Logit model based on the entropy maximization theory.The bi-level model is then transformed into a single-level model by the Karush-Kuhn-Tucker condition which is solved by the relaxation iterative algorithm.The results show that subsidies can promote the growth of sea-rail intermodal transportation volume,mainly from the volume transferred through road-sea intermodal transportation,with a small amount from water-water intermodal transportation.Compared to the uncoordinated subsidy,the coordinated subsidy significantly reduces the subsidy amount per container and increases the volume.Moreover,time value affects the effectiveness of subsidies,and the best results can be obtained by providing subsidies to shippers with medium-time value goods.
关键词
综合运输/补贴/双层规划模型/海铁联运/能力约束型巢式Logit模型
Key words
integrated transportation/subsidies/bi-level programming model/sea-rail intermodal transportation/capability constrained nested Logit model
维普
万方数据