Optimizing transfer operations for air-rail intermodal shipments: A case study of Zhengzhou aviation hub

Zhengzhou, with its unique “*” shaped high-speed rail network and strong advantages as an aviation hub, is leading a new trend in air-rail intermodal freight transportation, continuously enhancing its competitiveness in the global logistics. This paper focuses on the transfer operations of intermodal freight at the air-rail hub, investigating the integrated optimization of the cargo transfer scheme and the train template to ensure the most effective connection between flights and trains. Considering constraints such as the operational capacity of airports and high-speed rail stations, as well as the availability of facilities and resources, we developed a mixed-integer programming model. This model aims to minimize both cargo transfer time and the volume of remaining cargo. In the experimental section, we validated the model’s performance under large-scale scenarios using a model solver and quantitatively analyzed the relationship between the two objectives. These two objectives are integrated into a single objective function via a linear weighted sum, achieving a quantifiable trade-off between transfer efficiency and distribution levels. Finally, through sensitivity analysis, we discussed the impact of train loading rates and service time windows on the efficiency of intermodal cargo transfers. The results indicate that higher loading rate requirements tend to extend the average transfer time for cargo, while longer service time windows reduce the average transfer time. Both scenarios facilitate trains serving a greater number of flights.