[论文解读] Modular Vehicle Routing for Combined Passenger and Freight Transport

Jonas Hatzenbühler, Erik Jenelius+2 more|arXiv (Cornell University)|Sep 3, 2022

Urban and Freight Transport Logistics被引用 14

一句话总结

本文提出了一种新颖的模块化车辆路径规划框架，通过允许多功能车辆编队行驶，整合乘客与货运运输，联合优化两类需求。采用定制化的取送货问题，通过CPLEX与自适应大邻域搜索求解，实现总成本降低57%，空驶车公里数减少60%以上，证明了通过模块化与需求整合可显著提升效率。

ABSTRACT

The continuous increase in urban deliveries and the ongoing urbanization of large cities require the development of efficient and sustainable transportation solutions. This study investigates the impact of modular vehicle concepts and the consolidation of different demand types in the route planning on the efficiency of the urban freight and passenger transportation system. Modularity is achieved by connecting multiple vehicles together to form a platoon. The consolidation of different demand types is realized by simultaneously consider passenger and freight demand in the optimization algorithm. The considered vehicles are specific for each demand type by can be connected freely, hence it is possible to transport different demand types in the same platoon. The cost terms in the problem formulation are comprised of travel time costs, travel distance costs, fleet size costs, and cost considering unserved requests. The modular vehicle operations are modeled in a novel pickup and delivery problem which is solved using CPLEX and Adaptive Large Neighborhood Search. In an extensive scenario study and case study in Stockholm, the potentials of the new modular vehicle type are explored for different spatial and temporal demand distributions. A parameter study on vehicle capacity, vehicle range and cost saving assumptions is performed to study their influence on the efficiency. The experiments carried out indicate a general cost savings of 48% due to modularity and an additional 9% due to consolidation. The reduction mainly stems from reduced operating costs and reduced trip duration, while the same number of requests can be served in all cases. Empty vehicle kilometers are reduced by more than 60% by consolidation and modularity. The proposed model and optimization framework can be used by companies and policy makers to identify required fleet sizes, optimal vehicle routes and cost savings.

研究动机与目标

• 为应对城市日益增长的货运与客运需求，开发一种集成化、高效且可持续的路径规划解决方案。
• 研究模块化车辆运营（车辆可耦合为编队）对城市货运与客运运输效率的影响。
• 评估在单一优化框架中整合乘客与货运需求所带来的协同效益。
• 通过情景与参数研究量化成本节约、行程时间缩短以及空驶车公里数的降低。
• 为运输运营商与政策制定者提供一种实用且可扩展的优化框架，以评估新型车辆技术下的车队规模、路径规划与成本效率。

提出的方法

• 提出一种新型取送货问题变体，纳入模块化车辆运营机制，即车辆可耦合为编队，并同时服务乘客与货运需求。
• 模型包含四个成本分量：行驶时间、行驶距离、车队规模以及未服务需求的惩罚。
• 采用混合求解方法：对较小规模实例使用CPLEX进行精确求解，对较大且复杂的场景则采用自适应大邻域搜索（ALNS）求解。
• 在多种情景下对空间与时间上的需求模式进行建模，以评估在不同城市条件下的性能表现。
• 通过参数研究调整车辆容量、续航里程与成本假设，评估其对系统效率的影响。
• 以斯德哥尔摩的真实案例研究验证了该模型在实际城市环境中的适用性。

实验结果

研究问题

• RQ1 在城市客运与货运运输中，模块化车辆编队能在多大程度上降低总运营成本？
• RQ2 在单一路径优化中整合乘客与货运需求，能带来多大的额外效率提升？
• RQ3 车辆容量、续航里程与成本假设对整体成本节约与系统性能有何影响？
• RQ4 在模块化与整合化运营下，空驶车公里数与行程时间如何变化？
• RQ5 所提出的模型在现实城市环境（如斯德哥尔摩）中的适用性如何？

主要发现

• 模块化车辆系统通过编队行驶实现48%的总成本降低，通过需求整合再实现9%的额外节省，合计总成本降低57%。
• 由于模块化与需求整合的共同作用，空驶车公里数减少了60%以上。
• 由于行程减少、单次行程变长且载荷利用率提高，行程时间减少了60%以上。
• 在所有情景下，服务请求数量保持不变，表明效率提升未以牺牲服务质量为代价。
• 斯德哥尔摩案例研究证实了该模块化运输系统在真实城市环境中的实际可行性与可扩展性。
• 模型的假设（如固定编队配置与已知需求）虽限制了理论上的潜在收益，但显著增强了其在现实场景中的适用性。