Abstract

Trailer detention at delivery locations, frequently caused by the time-consuming (un)packing process, presents a significant challenge in container drayage. Despite extensive research on container drayage, the specific issues stemming from trailer detention remain relatively underexplored. This study addresses a trailer-detention-constrained multi-trailer drop-and-pull container drayage problem, incorporating flexible service starting times and time windows. The detained trailers differ from standard trailers as they require only a single pickup operation within the planning horizon, rather than the typical two-step delivery and subsequent pickup. These pickup operations must be completed within specified time windows due to their potential to disrupt logistics efficiency and often require time-sensitive handling. Furthermore, time windows are imposed on normal trailer deliveries, as these operations initiate the (un)packing process, which can impact the operational efficiency of customer activities. The problem involves tractors capable of towing multiple trailers, utilizing the drop-and-pull method for detachment and reattachment. Tractors possess the flexibility to select their service starting times. To address the inherent complexity of this problem, a mixed-integer programming model is developed alongside a tailored heuristic algorithm. The algorithm leverages a modified Clarke-and-Wright algorithm to generate both rapid and high-quality initial solutions. It strategically integrates the mathematical model, ensuring solution quality is maintained without compromising computational efficiency. To further enhance solution efficiency, a route-based release-fix-optimize method is implemented. Extensive computational experiments validate the efficacy of the proposed methods and examine the impact of time windows and detained inbound and outbound requests on transportation plans, offering valuable insights for effectively managing logistics systems.