Pub Date : 2026-05-01Epub Date: 2026-02-12DOI: 10.1016/j.tre.2026.104729
Xi Lin , Fang He , Meng Li , Xindi Tang , Chengyu Du
At busy terminal taxi stands, passengers and taxi drivers frequently experience prolonged waiting times due to congestion and inefficient matching processes. This study develops micro-level analytical models specifically tailored to capture the stochastic passenger boarding process and on-site operational controls, including passenger admission batch sizes and taxi stop-line positioning, using Markov chain and probability theory. We primarily analyze two representative operational scenarios: one characterized by a single long queue (typically of taxis) and another involving simultaneous congestion in both taxi and passenger queues. Both analytical and numerical results indicate that simple changes can result in substantial reductions in passenger waiting times and improvements in taxi outflow. The analytical framework is further extended to scenarios permitting spatial redesign or new boarding points, thereby broadening its applicability to diverse operating conditions. We further conduct time-of-day simulations with time-varying passenger and taxi arrivals to examine how the proposed strategies enhance the experiences of both passengers and taxi drivers in more realistic operating environments. The proposed strategies are rigorously validated through extensive numerical simulations and calibration with empirical data, highlighting significant real-world efficiency improvements and practical viability.
{"title":"Improving operations strategies at busy taxi stands: An analytical approach","authors":"Xi Lin , Fang He , Meng Li , Xindi Tang , Chengyu Du","doi":"10.1016/j.tre.2026.104729","DOIUrl":"10.1016/j.tre.2026.104729","url":null,"abstract":"<div><div>At busy terminal taxi stands, passengers and taxi drivers frequently experience prolonged waiting times due to congestion and inefficient matching processes. This study develops micro-level analytical models specifically tailored to capture the stochastic passenger boarding process and on-site operational controls, including passenger admission batch sizes and taxi stop-line positioning, using Markov chain and probability theory. We primarily analyze two representative operational scenarios: one characterized by a single long queue (typically of taxis) and another involving simultaneous congestion in both taxi and passenger queues. Both analytical and numerical results indicate that simple changes can result in substantial reductions in passenger waiting times and improvements in taxi outflow. The analytical framework is further extended to scenarios permitting spatial redesign or new boarding points, thereby broadening its applicability to diverse operating conditions. We further conduct time-of-day simulations with time-varying passenger and taxi arrivals to examine how the proposed strategies enhance the experiences of both passengers and taxi drivers in more realistic operating environments. The proposed strategies are rigorously validated through extensive numerical simulations and calibration with empirical data, highlighting significant real-world efficiency improvements and practical viability.</div></div>","PeriodicalId":49418,"journal":{"name":"Transportation Research Part E-Logistics and Transportation Review","volume":"209 ","pages":"Article 104729"},"PeriodicalIF":8.8,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146174546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-02-14DOI: 10.1016/j.tre.2026.104725
Xueli Ma , Na Wang , Qingguo Bai
This paper deals with technological upgrading investment, encroachment and technology licensing in a supply chain comprised of an original equipment manufacturer (OEM) and a contract manufacturer (CM), in which the OEM is a quality and quantity leader. We characterize the equilibrium strategies of the OEM and the CM in five scenarios. By comparing the equilibrium outcomes in different scenarios, we examine the interactions between the OEM’s technological upgrading investment and the CM’s encroachment strategies considering royalty-based technology licensing between them. Our analysis demonstrates that neither the OEM’s technological upgrading investment nor royalty charges can effectively prevent the CM from encroaching downstream market. Conversely, the CM’s encroachment increases the OEM’s incentive to make technological upgrading investment for the CM. We further prove that win–win situation can be achieved in situations involving investment and encroachment. This paper breaks the traditional notion that low substitution degree is always preferable for the OEM or the CM and demonstrates that win–win situation is only available when market advantage is not weak. We also show that there always exist suboptimal strategies for the CM and the OEM when win–win situation is not available and analyze the effects of substitution degree, market advantage and brand advantage on the shift of win–win situation or suboptimal strategies. Furthermore, we consider two extended models: a sequential game where the CM acts as a first-mover, and a simultaneous quantity competition game. We characterize the conditions to achieve win–win situation in different models.
{"title":"Technological Upgrading Investment and Encroachment Strategies in an Outsourcing Supply Chain with Licensing","authors":"Xueli Ma , Na Wang , Qingguo Bai","doi":"10.1016/j.tre.2026.104725","DOIUrl":"10.1016/j.tre.2026.104725","url":null,"abstract":"<div><div>This paper deals with technological upgrading investment, encroachment and technology licensing in a supply chain comprised of an original equipment manufacturer (OEM) and a contract manufacturer (CM), in which the OEM is a quality and quantity leader. We characterize the equilibrium strategies of the OEM and the CM in five scenarios. By comparing the equilibrium outcomes in different scenarios, we examine the interactions between the OEM’s technological upgrading investment and the CM’s encroachment strategies considering royalty-based technology licensing between them. Our analysis demonstrates that neither the OEM’s technological upgrading investment nor royalty charges can effectively prevent the CM from encroaching downstream market. Conversely, the CM’s encroachment increases the OEM’s incentive to make technological upgrading investment for the CM. We further prove that win–win situation can be achieved in situations involving investment and encroachment. This paper breaks the traditional notion that low substitution degree is always preferable for the OEM or the CM and demonstrates that win–win situation is only available when market advantage is not weak. We also show that there always exist suboptimal strategies for the CM and the OEM when win–win situation is not available and analyze the effects of substitution degree, market advantage and brand advantage on the shift of win–win situation or suboptimal strategies. Furthermore, we consider two extended models: a sequential game where the CM acts as a first-mover, and a simultaneous quantity competition game. We characterize the conditions to achieve win–win situation in different models.</div></div>","PeriodicalId":49418,"journal":{"name":"Transportation Research Part E-Logistics and Transportation Review","volume":"209 ","pages":"Article 104725"},"PeriodicalIF":8.8,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146174549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-02-03DOI: 10.1016/j.tre.2026.104720
Shuanglu Zhang, Xiuwen Wang, Lu Zhen
Wind-assisted propulsion systems (WAPS) have emerged as a promising technology in the shipping industry. The utilization of wind energy can provide auxiliary thrust and hence reduce the fuel consumption as well as carbon emissions of wind-assisted ships. However, the rigid structure of a traditional shipping service is often suboptimal for harnessing wind energy effectively. This paper explores a shipping service design problem for wind-assisted ships, which is formulated as a two-stage stochastic mixed-integer programming model. The first-stage decisions determine the optimal port visit sequence of all ports, while the second-stage decisions adapt the ship’s schedule under a set of wind scenarios to minimize expected total voyage costs, including fuel, operational, and delay-related expenses. A Benders decomposition algorithm is utilized to solve the stochastic model. The model is applied to a realistic trans-Pacific case study. The results of a comparative analysis against a conventional shipping case indicate the superiority of wind-assisted ships in reducing both costs and carbon emissions. Furthermore, a comprehensive sensitivity analysis reveals that the economic advantage of the integration of WAPS technology and stochastic optimization is robust, providing shipping companies with a practical and profitable strategy towards sustainable operations.
{"title":"Shipping service design for wind-assisted ships","authors":"Shuanglu Zhang, Xiuwen Wang, Lu Zhen","doi":"10.1016/j.tre.2026.104720","DOIUrl":"10.1016/j.tre.2026.104720","url":null,"abstract":"<div><div>Wind-assisted propulsion systems (WAPS) have emerged as a promising technology in the shipping industry. The utilization of wind energy can provide auxiliary thrust and hence reduce the fuel consumption as well as carbon emissions of wind-assisted ships. However, the rigid structure of a traditional shipping service is often suboptimal for harnessing wind energy effectively. This paper explores a shipping service design problem for wind-assisted ships, which is formulated as a two-stage stochastic mixed-integer programming model. The first-stage decisions determine the optimal port visit sequence of all ports, while the second-stage decisions adapt the ship’s schedule under a set of wind scenarios to minimize expected total voyage costs, including fuel, operational, and delay-related expenses. A Benders decomposition algorithm is utilized to solve the stochastic model. The model is applied to a realistic <em>trans</em>-Pacific case study. The results of a comparative analysis against a conventional shipping case indicate the superiority of wind-assisted ships in reducing both costs and carbon emissions. Furthermore, a comprehensive sensitivity analysis reveals that the economic advantage of the integration of WAPS technology and stochastic optimization is robust, providing shipping companies with a practical and profitable strategy towards sustainable operations.</div></div>","PeriodicalId":49418,"journal":{"name":"Transportation Research Part E-Logistics and Transportation Review","volume":"209 ","pages":"Article 104720"},"PeriodicalIF":8.8,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-02-03DOI: 10.1016/j.tre.2026.104719
Yukuan Wang , Ryan Wen Liu , Jingxian Liu , Lichao Yang , Yang Liu , Miquel Angel Piera Eroles
The surge in electric vehicles (EVs) is causing a structural disruption to high-density, short-sea Roll-on/Roll-off (RoRo) transportation, driven by stricter safety regulations and unique transport protocols. Operators like those in China’s Qiongzhou Strait have implemented an ‘EV Dedicated Service’ (EVDS) strategy. This strategy involves a complex coordination problem between dedicated EV-carrying vessels and separate vessels for transporting drivers. However, this emerging scheduling paradigm has been insufficiently studied. This paper proposes a multi-objective mixed integer programming model for the RoRo fleet scheduling with a novel methodological approach to formulate EVDS mechanism. Additionally, we develop an Adaptive Large Neighborhood Search − based heuristic algorithm, featuring novel problem-specific neighborhood structures. Realistic instances validated the algorithm’s performance against benchmark methods. The results also revealed the balance between economic efficiency and service levels across three different demand scenarios (Low-Season, Normal-Day, and Peak-Season). Furthermore, the analysis reveals the strategic value of flexible deployment for EV-certified vessels. We also introduce a method to quantify operational resilience by analyzing the impact of elastic capacity planning on alleviating port congestion. The findings provide a robust decision-support framework for RoRo operators and policymakers navigating the surge in EV transport demand.
{"title":"Resilient RoRo fleet scheduling for mixed EV and ICEV transport demand: An optimization framework for EV dedicated service strategy","authors":"Yukuan Wang , Ryan Wen Liu , Jingxian Liu , Lichao Yang , Yang Liu , Miquel Angel Piera Eroles","doi":"10.1016/j.tre.2026.104719","DOIUrl":"10.1016/j.tre.2026.104719","url":null,"abstract":"<div><div>The surge in electric vehicles (EVs) is causing a structural disruption to high-density, short-sea Roll-on/Roll-off (RoRo) transportation, driven by stricter safety regulations and unique transport protocols. Operators like those in China’s Qiongzhou Strait have implemented an ‘EV Dedicated Service’ (EVDS) strategy. This strategy involves a complex coordination problem between dedicated EV-carrying vessels and separate vessels for transporting drivers. However, this emerging scheduling paradigm has been insufficiently studied. This paper proposes a multi-objective mixed integer programming model for the RoRo fleet scheduling with a novel methodological approach to formulate EVDS mechanism. Additionally, we develop an Adaptive Large Neighborhood Search − based heuristic algorithm, featuring novel problem-specific neighborhood structures. Realistic instances validated the algorithm’s performance against benchmark methods. The results also revealed the balance between economic efficiency and service levels across three different demand scenarios (Low-Season, Normal-Day, and Peak-Season). Furthermore, the analysis reveals the strategic value of flexible deployment for EV-certified vessels. We also introduce a method to quantify operational resilience by analyzing the impact of elastic capacity planning on alleviating port congestion. The findings provide a robust decision-support framework for RoRo operators and policymakers navigating the surge in EV transport demand.</div></div>","PeriodicalId":49418,"journal":{"name":"Transportation Research Part E-Logistics and Transportation Review","volume":"209 ","pages":"Article 104719"},"PeriodicalIF":8.8,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-02-02DOI: 10.1016/j.tre.2026.104712
Siqi Shu , Xinyue Yang , Zhuang Ming , Xiaoxiang Na , Marc E.J. Stettler , Der-Horng Lee , Simon Hu
Urban freight transport faces significant decarbonization pressure, yet existing strategies such as freight pooling and electric truck adoption often struggle with limited uptake due to operational complexities, costs, and infrastructure challenges. Critically, current research lacks an integrated, operational incentive framework specifically designed for multi-stakeholder participation in urban crowdsourced logistics, where task-level operational decisions across multiple stakeholders play a central role in system-level carbon reduction. This study introduces a Carbon Reduction Incentive Model (CRIM) that addresses this gap. The CRIM incentivizes individual shippers and independent carriers within a crowdsourced logistics system by assigning task-level rewards for freight pooling and electric truck usage. Rewards are quantified by tonne-kilometer savings relative to conventional individual diesel deliveries, further adjusted by a time-based factor to encourage off-peak operations. The CRIM is embedded within an enhanced pick-up and delivery model that explicitly accounts for stakeholder cost components, vehicle heterogeneity, charging requirements, and time-sensitive feasibility (PDPTW-HEC). To optimize the system’s complex trade-off between costs and carbon emissions, a customized heuristic algorithm is developed. Scenario-based case studies using real-world data and international carbon accounting standards validate the proposed incentive model’s performance. Results demonstrate that CRIM can achieve 9.5–38.1% higher electric truck adoption and an 8.4–28.7% reduction in total carbon emissions. This framework offers a practical and scalable approach for designing and evaluating task-level carbon reduction incentives in urban freight operations.
{"title":"A carbon reduction incentive model for crowdsourced urban freight: Facilitating freight pooling and electric truck adoption","authors":"Siqi Shu , Xinyue Yang , Zhuang Ming , Xiaoxiang Na , Marc E.J. Stettler , Der-Horng Lee , Simon Hu","doi":"10.1016/j.tre.2026.104712","DOIUrl":"10.1016/j.tre.2026.104712","url":null,"abstract":"<div><div>Urban freight transport faces significant decarbonization pressure, yet existing strategies such as freight pooling and electric truck adoption often struggle with limited uptake due to operational complexities, costs, and infrastructure challenges. Critically, current research lacks an integrated, operational incentive framework specifically designed for multi-stakeholder participation in urban crowdsourced logistics, where task-level operational decisions across multiple stakeholders play a central role in system-level carbon reduction. This study introduces a Carbon Reduction Incentive Model (CRIM) that addresses this gap. The CRIM incentivizes individual shippers and independent carriers within a crowdsourced logistics system by assigning task-level rewards for freight pooling and electric truck usage. Rewards are quantified by tonne-kilometer savings relative to conventional individual diesel deliveries, further adjusted by a time-based factor to encourage off-peak operations. The CRIM is embedded within an enhanced pick-up and delivery model that explicitly accounts for stakeholder cost components, vehicle heterogeneity, charging requirements, and time-sensitive feasibility (PDPTW-HEC). To optimize the system’s complex trade-off between costs and carbon emissions, a customized heuristic algorithm is developed. Scenario-based case studies using real-world data and international carbon accounting standards validate the proposed incentive model’s performance. Results demonstrate that CRIM can achieve 9.5–38.1% higher electric truck adoption and an 8.4–28.7% reduction in total carbon emissions. This framework offers a practical and scalable approach for designing and evaluating task-level carbon reduction incentives in urban freight operations.</div></div>","PeriodicalId":49418,"journal":{"name":"Transportation Research Part E-Logistics and Transportation Review","volume":"209 ","pages":"Article 104712"},"PeriodicalIF":8.8,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-02-09DOI: 10.1016/j.tre.2026.104739
Junkai Zhang, Kap Hwan Kim, Ningning Song, Xuehao Feng
The yard slot allocation problem (SAP), which concerns locating containers in the storage yard, could critically affect the performance of ports. The optimization of this problem is challenging due to the complex operational conditions and real-time decision requirement in practice. As a new type of layout, the U-shaped layout offers external and internal trucks (ETs and ITs) novel combinations of travel routes and container handover points that may result in unique characteristics for the SAP. This study addresses the SAP under the U-shaped layout to minimize the delay time of ITs and ETs. A novel simulation-based evaluation method considering multiple criteria is proposed to allocate slots for arriving containers. In this method, an evolving neural decision network (ENDN) is developed to explore the influence of real-time information on the weights of these criteria. We develop an efficient genetic algorithm tailored to optimize the parameters of the ENDN. A simulation model is developed to evaluate the algorithm’s performance under realistic operational uncertainties that may promote the practical implementation of the ENDN. The experimental results demonstrate that our method can determine slot allocations of shorter total vehicle delay time compared with existing methods.
{"title":"Simulation-based optimization of yard slot allocation in U-shaped container terminals","authors":"Junkai Zhang, Kap Hwan Kim, Ningning Song, Xuehao Feng","doi":"10.1016/j.tre.2026.104739","DOIUrl":"10.1016/j.tre.2026.104739","url":null,"abstract":"<div><div>The yard slot allocation problem (SAP), which concerns locating containers in the storage yard, could critically affect the performance of ports. The optimization of this problem is challenging due to the complex operational conditions and real-time decision requirement in practice. As a new type of layout, the U-shaped layout offers external and internal trucks (ETs and ITs) novel combinations of travel routes and container handover points that may result in unique characteristics for the SAP. This study addresses the SAP under the U-shaped layout to minimize the delay time of ITs and ETs. A novel simulation-based evaluation method considering multiple criteria is proposed to allocate slots for arriving containers. In this method, an evolving neural decision network (ENDN) is developed to explore the influence of real-time information on the weights of these criteria. We develop an efficient genetic algorithm tailored to optimize the parameters of the ENDN. A simulation model is developed to evaluate the algorithm’s performance under realistic operational uncertainties that may promote the practical implementation of the ENDN. The experimental results demonstrate that our method can determine slot allocations of shorter total vehicle delay time compared with existing methods.</div></div>","PeriodicalId":49418,"journal":{"name":"Transportation Research Part E-Logistics and Transportation Review","volume":"209 ","pages":"Article 104739"},"PeriodicalIF":8.8,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-02-03DOI: 10.1016/j.tre.2026.104700
Yanqin Chen , Changxin Liao , Jia Yao , David Z.W. Wang , Anthony Chen
This paper introduces capacity constraints into a multi-modal transportation network, including solo driving, carpooling, and public transit, and proposes two queuing toll policies based on the cost-sharing characteristics of carpooling to eliminate physical queues. By incorporating traveler heterogeneity in the value of time, a multi-class user equilibrium model is developed to assess the impacts of capacity constraints and queuing toll policies on traffic equilibrium under three cases: 1) case 1, no tolls are charged to any travelers. Physical queues may occur on the saturated links; 2) case 2, the queuing tolls are charged exclusively to solo drivers, and it takes into account the scenario that the physical queues are not completely eliminated in the saturated link only with carpooling; 3) case 3, the queuing tolls are charged to solo drivers and carpooling travelers (i.e., carpooling drivers and riders). Then, an improved route swapping algorithm is proposed to solve the equilibrium model. Finally, numerical analysis based on the Winnipeg network is conducted to demonstrate the properties of the problem and the performance of the proposed model and algorithm. The results show that the proposed queuing toll policies can improve travel efficiency by encouraging carpooling and eliminating physical queues. Moreover, the differential impacts of the three cases on heterogeneous travelers’ mode choices and travel efficiency are explored. These findings provide a theoretical basis for the practical implementation of queuing toll policies.
{"title":"A model for queuing toll policies incorporating cost-sharing characteristics of carpooling in the transportation network with capacity constraints","authors":"Yanqin Chen , Changxin Liao , Jia Yao , David Z.W. Wang , Anthony Chen","doi":"10.1016/j.tre.2026.104700","DOIUrl":"10.1016/j.tre.2026.104700","url":null,"abstract":"<div><div>This paper introduces capacity constraints into a multi-modal transportation network, including solo driving, carpooling, and public transit, and proposes two queuing toll policies based on the cost-sharing characteristics of carpooling to eliminate physical queues. By incorporating traveler heterogeneity in the value of time, a multi-class user equilibrium model is developed to assess the impacts of capacity constraints and queuing toll policies on traffic equilibrium under three cases: 1) case 1, no tolls are charged to any travelers. Physical queues may occur on the saturated links; 2) case 2, the queuing tolls are charged exclusively to solo drivers, and it takes into account the scenario that the physical queues are not completely eliminated in the saturated link only with carpooling; 3) case 3, the queuing tolls are charged to solo drivers and carpooling travelers (i.e., carpooling drivers and riders). Then, an improved route swapping algorithm is proposed to solve the equilibrium model. Finally, numerical analysis based on the Winnipeg network is conducted to demonstrate the properties of the problem and the performance of the proposed model and algorithm. The results show that the proposed queuing toll policies can improve travel efficiency by encouraging carpooling and eliminating physical queues. Moreover, the differential impacts of the three cases on heterogeneous travelers’ mode choices and travel efficiency are explored. These findings provide a theoretical basis for the practical implementation of queuing toll policies.</div></div>","PeriodicalId":49418,"journal":{"name":"Transportation Research Part E-Logistics and Transportation Review","volume":"209 ","pages":"Article 104700"},"PeriodicalIF":8.8,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-02-06DOI: 10.1016/j.tre.2026.104714
Xuan Lu , Yu Zhang , Xuri Xin , Hang Yang , Huanhuan Li , Lanbo Zheng , Zaili Yang
In this research, an integrated inbound and outbound operational planning and scheduling problem is addressed for complex and large bulk ports. The practice of moving homogeneous dry bulk cargoes on a fixed terminal is changing as raw materials of different types are transported from/to the same terminals. It raises a new research challenge where unloading, stacking, reclaiming, conveying and loading operations must be coordinated to import/export blended products according to the tight specifications of customers. This paper aims to maximise resource utilisation and to satisfy demands as early as possible. The essence of the problem is to design the routing of product flows throughout the port logistics network such that supply and demand are matched optimally. This study presents a new framework that enables the modelling of the planning part as a multi-commodity flow problem and the scheduling part as a constraint programming (CP) problem. A novel dual-engine optimisation method that synergistically combines CP with deep reinforcement learning (DRL) is proposed to accelerate the scheduling phase. The method leverages DRL agents to fix key variables, thereby effectively accelerating the optimisation process of the CP solver. Comprehensive numerical experiments are conducted on real data sets as well as instances derived from real scenarios to validate the effectiveness of the proposed approach, demonstrating significant improvements in port scheduling efficiency. Additionally, strategic management analyses offer actionable insights to support decision-making in bulk port operations. The proposed methods provide a generalised methodology adaptable to a broad range of complex combinatorial optimisation problems in port logistics and beyond, paving the way for more intelligent and sustainable dry bulk port management.
{"title":"Hierarchical planning and scheduling for bulk ports via network flow and deep reinforcement learning-guided constraint programming","authors":"Xuan Lu , Yu Zhang , Xuri Xin , Hang Yang , Huanhuan Li , Lanbo Zheng , Zaili Yang","doi":"10.1016/j.tre.2026.104714","DOIUrl":"10.1016/j.tre.2026.104714","url":null,"abstract":"<div><div>In this research, an integrated inbound and outbound operational planning and scheduling problem is addressed for complex and large bulk ports. The practice of moving homogeneous dry bulk cargoes on a fixed terminal is changing as raw materials of different types are transported from/to the same terminals. It raises a new research challenge where unloading, stacking, reclaiming, conveying and loading operations must be coordinated to import/export blended products according to the tight specifications of customers. This paper aims to maximise resource utilisation and to satisfy demands as early as possible. The essence of the problem is to design the routing of product flows throughout the port logistics network such that supply and demand are matched optimally. This study presents a new framework that enables the modelling of the planning part as a multi-commodity flow problem and the scheduling part as a constraint programming (CP) problem. A novel dual-engine optimisation method that synergistically combines CP with deep reinforcement learning (DRL) is proposed to accelerate the scheduling phase. The method leverages DRL agents to fix key variables, thereby effectively accelerating the optimisation process of the CP solver. Comprehensive numerical experiments are conducted on real data sets as well as instances derived from real scenarios to validate the effectiveness of the proposed approach, demonstrating significant improvements in port scheduling efficiency. Additionally, strategic management analyses offer actionable insights to support decision-making in bulk port operations. The proposed methods provide a generalised methodology adaptable to a broad range of complex combinatorial optimisation problems in port logistics and beyond, paving the way for more intelligent and sustainable dry bulk port management.</div></div>","PeriodicalId":49418,"journal":{"name":"Transportation Research Part E-Logistics and Transportation Review","volume":"209 ","pages":"Article 104714"},"PeriodicalIF":8.8,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146135122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-01-31DOI: 10.1016/j.tre.2026.104678
Sepehr Pasha, S.Mehdi Sajadifar
The use of drones alongside trucks for parcel delivery has received considerable research attention, further stimulated by advancements in drone capacity and range that enhance operational viability relative to traditional methods. In this paper, we address a variant of the combined truck-drone routing problem, entailing multiple trucks collaborating with drones to meet the pickup and delivery demands of customers. In the proposed problem, drone energy consumption depends on the carried load; drones may serve multiple customers per flight, and each truck can launch and retrieve its drone multiple times at each customer node (multi-LR) to enhance overall utilization. We propose a mixed-integer linear programming model to minimize total cost, enhanced with problem-specific cuts, which are demonstrated through extensive computational experiments to effectively reduce runtime. The model includes flexible features that allow it to handle diverse operational constraints, such as restrictions on the number of flights performed and high-traffic areas. Given the complexity of the model, we develop an adapted algorithm from the literature, incorporating significant modifications along with a new acceleration strategy. The approach combines a maximum payload method in the first stage with an improved simulated annealing algorithm using problem-specific neighborhood operators in the second stage. Although our findings show that the multi-LR feature increases the number of flights performed, both the model and the adapted algorithm demonstrate its cost efficiency, achieving average transportation cost reductions of 14.51% compared to the system without multi-LR and 45.62% compared to the traditional truck-only system.
{"title":"Enabling the multi-LR ability of drones in the multi-visit truck-drone routing problem with pickup and delivery","authors":"Sepehr Pasha, S.Mehdi Sajadifar","doi":"10.1016/j.tre.2026.104678","DOIUrl":"10.1016/j.tre.2026.104678","url":null,"abstract":"<div><div>The use of drones alongside trucks for parcel delivery has received considerable research attention, further stimulated by advancements in drone capacity and range that enhance operational viability relative to traditional methods. In this paper, we address a variant of the combined truck-drone routing problem, entailing multiple trucks collaborating with drones to meet the pickup and delivery demands of customers. In the proposed problem, drone energy consumption depends on the carried load; drones may serve multiple customers per flight, and each truck can launch and retrieve its drone multiple times at each customer node (multi-LR) to enhance overall utilization. We propose a mixed-integer linear programming model to minimize total cost, enhanced with problem-specific cuts, which are demonstrated through extensive computational experiments to effectively reduce runtime. The model includes flexible features that allow it to handle diverse operational constraints, such as restrictions on the number of flights performed and high-traffic areas. Given the complexity of the model, we develop an adapted algorithm from the literature, incorporating significant modifications along with a new acceleration strategy. The approach combines a maximum payload method in the first stage with an improved simulated annealing algorithm using problem-specific neighborhood operators in the second stage. Although our findings show that the multi-LR feature increases the number of flights performed, both the model and the adapted algorithm demonstrate its cost efficiency, achieving average transportation cost reductions of 14.51% compared to the system without multi-LR and 45.62% compared to the traditional truck-only system.</div></div>","PeriodicalId":49418,"journal":{"name":"Transportation Research Part E-Logistics and Transportation Review","volume":"209 ","pages":"Article 104678"},"PeriodicalIF":8.8,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146081788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-02-14DOI: 10.1016/j.tre.2026.104740
Zheng Li , Haoming Meng , Chengyuan Ma , Ke Ma , Xiaopeng Li
The Markov property serves as a foundational assumption in most existing work on vehicle driving behavior, positing that future states depend solely on the current state, not the series of preceding states. This study validates the Markov properties of vehicle trajectories for both Autonomous Vehicles (AVs) and Human-driven Vehicles (HVs). A statistical method used to test whether time series data exhibits Markov properties is applied to examine whether the trajectory data possesses Markov characteristics. Kolmogorov–Smirnov test and Brown–Forsythe test are additionally introduced to characterize the differences in Markov properties between AVs and HVs. Based on several public trajectory datasets, we investigate the presence and order of the Markov property of different types of vehicles through rigorous statistical tests. Our findings reveal that AV trajectories generally exhibit stronger Markov properties compared to HV trajectories, with a higher percentage conforming to the Markov property and lower Markov orders. In contrast, HV trajectories display greater variability and heterogeneity in decision-making processes, reflecting the complex perception and information processing involved in human driving. These results have significant implications for the development of driving behavior models, traffic flow models, and traffic simulation systems. Our study also demonstrates the feasibility of using statistical methods to test the presence of Markov properties in driving trajectory data.
{"title":"Assessing Markov property in driving behaviors: Insights from statistical tests","authors":"Zheng Li , Haoming Meng , Chengyuan Ma , Ke Ma , Xiaopeng Li","doi":"10.1016/j.tre.2026.104740","DOIUrl":"10.1016/j.tre.2026.104740","url":null,"abstract":"<div><div>The Markov property serves as a foundational assumption in most existing work on vehicle driving behavior, positing that future states depend solely on the current state, not the series of preceding states. This study validates the Markov properties of vehicle trajectories for both Autonomous Vehicles (AVs) and Human-driven Vehicles (HVs). A statistical method used to test whether time series data exhibits Markov properties is applied to examine whether the trajectory data possesses Markov characteristics. Kolmogorov–Smirnov test and Brown–Forsythe test are additionally introduced to characterize the differences in Markov properties between AVs and HVs. Based on several public trajectory datasets, we investigate the presence and order of the Markov property of different types of vehicles through rigorous statistical tests. Our findings reveal that AV trajectories generally exhibit stronger Markov properties compared to HV trajectories, with a higher percentage conforming to the Markov property and lower Markov orders. In contrast, HV trajectories display greater variability and heterogeneity in decision-making processes, reflecting the complex perception and information processing involved in human driving. These results have significant implications for the development of driving behavior models, traffic flow models, and traffic simulation systems. Our study also demonstrates the feasibility of using statistical methods to test the presence of Markov properties in driving trajectory data.</div></div>","PeriodicalId":49418,"journal":{"name":"Transportation Research Part E-Logistics and Transportation Review","volume":"209 ","pages":"Article 104740"},"PeriodicalIF":8.8,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146174550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}