Reducing truck emissions at container terminals in a low carbon economy: Proposal of a queueing-based bi-objective model for optimizing truck arrival pattern

This study proposes a methodology to optimize truck arrival patterns to reduce emissions from idling truck engines at marine container terminals. A bi-objective model is developed minimizing both truck waiting times and truck arrival pattern change. The truck waiting time is estimated via a queueing network. Based on the waiting time, truck idling emissions are estimated. The proposed methodology is evaluated with a case study, where truck arrival rates vary over time. We propose a Genetic Algorithm based heuristic to solve the resulting problem. Result shows that, a small shift of truck arrivals can significantly reduce truck emissions, especially at the gate.     

Space allocating strategies for improving import yard performance at marine terminals

This paper focuses on the organization of the import storage yard at container port terminals. Three new stacking strategies are introduced which take into account the containers’ arrival and departure rates and the storage yard characteristics. A mathematical model based on probabilistic distribution functions is developed to estimate the number of rehandles required to manage an import container yard. The model is applied to the three proposed stacking strategies. Results show that the optimal strategy depends on stacking height and the relationship between vessel headway and container dwell time.     

The value of specific cargo information for substitutable modes of inland transport

Communication about containers onboard a cargo carrier approaching a harbor with a hinterland operator who is to receive the containers usually reveals the total amount of goods (aggregate number of containers) to be transported inland upon unloading at the arrival dock. This communication is useful for the hinterland operator to plan and deploy its transport capacities. However, further transport of containers on the hinterland involve various transport modes at differing costs. For example, the delivery time requirement of a container dictates the most appropriate mode of inland transport, be it truck, rail, or barge, in decreasing order of speed, flexibility and cost, to move the container to the next destination. In general there may be several types of delivery time requirements and containers of each type is most economically moved inland in a corresponding transport mode. Trucking is usually used for containers that need urgent delivery and train or barge for not so urgent types. In order to efficiently plan the transport capacities for after-arrival conveyance of containers having multi-type delivery time requirements, not only should the aggregate number of containers, but also the number of containers of each type, be made available to the hinterland operator. We consider several information scenarios and in each scenario we solve a single-period capacity planning serving multi-type demands with product substitution. We then compare expected transport costs between information scenarios to evaluate the benefit of specific cargo information in improving the next-step transporting after containers are unloaded at the port of entry.     

The contribution of advanced package arrival information to efficient ground deliveries by international couriers

This paper quantifies how real-time access to information on the arrival status of packages consigned from overseas for subsequent truck transportation can contribute to the efficiency of international couriers’ ground delivery operations. The contribution is quantified by determining the eliminable ground transportation costs of next-best tactics that partially compensate for deficiencies in package arrival information. Next-best tactics include forecasting each package’s arrival status and adjusting ground delivery routes when actual arrival information becomes known. The study shows that the contribution can be significant, reaching hundreds of dollars per day. The study also finds that tactics using forecasts, even highly accurate forecasts, are not always the most effective next-best tactics.     

Using time-varying tolls to optimize truck arrivals at ports

An analytical point-wise stationary approximation model is proposed to analyze time-dependent truck queuing processes with stochastic service time distributions at gates and yards of a port terminal. A convex nonlinear programming model is developed which minimizes the total truck turn time and discomfort due to shifted arrival times. A two-phase optimization approach is used to first compute a system-optimal truck arrival pattern, and then find a desirable pattern of time-varying tolls that leads to the optimal arrival pattern. Numerical experiments are conducted to test the computational efficiency and accuracy of the proposed optimization models.     

Negotiating truck arrival times among trucking companies and a container terminal

Congestion of trucks in port areas has created serious environmental and traffic problems in many countries. One of main reasons for congestion is the concentrated arrivals of road trucks at peak hours. A negotiation process for smoothing truck arrivals in peak hours among multiple trucking companies and a terminal is addressed. The negotiation process is to be used for the appointment system for road trucks in container terminals. This paper suggests a mathematical formulation for smoothing the peaks in arrivals considering the inconvenience of trucks from changing their arrival times and the waiting cost of trucks in peak hours. This study proposes a decentralized decision-making model to support the negotiation process between truck companies and the terminal operator. It gives an acceptable solution to every player involved as well as the near optimal solution to the entire system from the global point of view. Numerical experiments are performed to validate the approach in this study.     

美国铁路集装箱运输对我国的启示

铁路集装箱运输有其独有优势。介绍了美国铁路集装箱运输现状，分析了我国铁路集装箱运输形式和现状．探讨了我国铁路集装箱运输广大的市场前景和实现良好经济效益的途径。     

Optimization of loading sequence and rehandling strategy for multi-quay crane operations in container terminals

In this paper, we consider the optimization of loading sequence and rehandling strategy in the terminal operation. We present an optimization strategy to minimize the number of rehandles, and establish a mathematical model to integrate the loading sequence and the rehandling strategy under the parallel operation of multi-quay cranes. Furthermore, we give an improved genetic algorithm to solve the model. We show the efficiency of the optimization strategy and algorithm by comparing them with previous strategies and heuristics.     

A reactive tabu search algorithm for the multi-depot container truck transportation problem

A container truck transportation problem that involves multiple depots with time windows at both origins and destinations, including the reposition of empty containers, is formulated as a multi-traveling salesman problem with time windows (m-TSPTW) with multiple depots. Since the problem is NP-hard, a cluster method and a reactive tabu search (RTS) algorithm are developed to solve the problem. The two methods are compared with the mixed integer program which can be used to find optimum solutions for small size problems. The computational results show that the developed methods, particularly the RTS algorithm, can be efficiently used to solve the problem.     

A heuristic algorithm for yard truck scheduling and storage allocation problems

The yard truck scheduling and the storage allocation are two important decision problems affecting the efficiency of container terminal operations. This paper proposes a novel approach that integrates these two problems into a whole. The objective is to minimize the weighted sum of total delay of requests and the total travel time of yard trucks. Due to the intractability of the proposed problem, a hybrid insertion algorithm is designed for effective problem solutions. Computational experiments are conducted to examine the key factors of the problem and the performance of the proposed heuristic algorithm.     

加快铁路货运专线建设推动集装箱中心站和港口一体化

论述修建上海至西安和深圳至昆明两条集装箱货运专线的必要性、效益及建设模式、运营前景，认为推动铁路货运专线、集装箱中心和港口一体化运作，可以从根本上改善物流效率。     

A modified ant colony optimization algorithm for multi-item inventory routing problems with demand uncertainty

This paper addresses an integrated model that schedules multi-item replenishment with uncertain demand to determine delivery routes and truck loads, where the actual replenishment quantity only becomes known upon arrival at a demand location. This paper departs from the conventional ant colony optimization (ACO) algorithm, which minimizes total travel length, and incorporates the attraction of pheromone values that indicate the stockout costs on nodes. The contributions of the paper to the literature are made both in terms of modeling this combined multi-item inventory management with the vehicle-routing problem and in introducing a modified ACO for the inventory routing problem.     

The integrated yard truck and yard crane scheduling problem: Benders’ decomposition-based methods

This paper proposes a novel integrated model for yard truck and yard crane scheduling problems for loading operations in container terminal. The problem is formulated as a mixed-integer programming model. Due to the computational intractability, two efficient solution methods, based on Benders’ decomposition, are developed for problem solution; namely, the general Benders’ cut-based method and the combinatorial Benders’ cut-based method. Computational experiments are conducted to evaluate the effectiveness of the proposed solution methods.     

Container drayage problem with flexible orders and its near real-time solution strategies

This article studies a container drayage problem with flexible orders defined by using requiring and releasing attributes as a unified formulation of various order types. A determined-activities-on-vertex (DAOV) graph introduces a temporary vertex set to formulate different truck statuses. The problem is formulated as a mixed-integer nonlinear programming model based on the DAOV graph. Four strategies including a window partition based (WPB) strategy are presented and evaluated extensively to solve the problem. Results indicate that the WPB method could solve the problem effectively and efficiently. Furthermore, this method is robust considering the operating time biases compared to other algorithms.     

A polynomial-time heuristic for the quay crane double-cycling problem with internal-reshuffling operations

One of great challenges in seaport management is how to handle containers under reshuffling, called reshuffles. Repositioning reshuffles in a bay (internal reshuffling) can improve the efficiency of quay cranes and help ports to reduce ship turn-around time. This paper studies the quay crane double-cycling problem with internal-reshuffling operations, and presents a fast solution algorithm. To reduce the number of operations necessary to turn around a bay of a vessel, the problem is first formulated as a new integer program. A polynomial-time heuristic is then developed. The analysis is made on the worst-case error bound of the proposed algorithm. Results are presented for a suite of combinations of problem instances with different bay sizes and workload scenarios. Comparisons are made between our algorithm and the start-of-the-art heuristic. The computational results demonstrate that our model can be solved more efficiently with CPLEX than the model proposed by Meisel and Wichmann (2010), and the proposed algorithm can well solve real-world problem instances within several seconds.     

Estimating an origin–destination table for US imports of waterborne containerized freight

Containerized freight imports into the US are growing at an average of 10% per year. This traffic is concentrated at a small number of US seaports. It is therefore important to have an accurate understanding of the flow of containers from their origin country through these seaports to their final destination. This paper develops an optimization model to estimate route flows and a corresponding multi-modal origin–destination table for containers by synthesizing data on international trade and railcar movements with a gravity model for the demand of container traffic. This analysis provides insights into the balance of rail and truck inland transportation from each port.     

国际集装箱中转站经济评价

通过对国际集装箱中转站功能的分析,论述了财务分析中各种运营收入、成本的测算方法;在经济分析中运用“有无对比法”,对国民经济效益进行了计算。提出为促进我国集装箱运输事业的发展,项目评价作为决策的中心地位应得到加强,项目评价方法也应进一步规范。     

Container storage and transshipment marine terminals

This study addresses the storage arrangement of transshipment containers on a container yard, in order to carry out efficiently the ship handling operations at a terminal where mega-containerships call. An optimization model is specified to investigate the flow of containers from the mega-containership to feeder ships using intermediate storage at the yard. A heuristic based on the lagrangian relaxation is formulated. The quality of the heuristic approach is tested in a number of experiments. In the experiments, various situations are analyzed with respect to mega-containership arrival rates, some strategies for stack arrangements and terminal layouts.     

专用铁路集装箱江海联运驳接方式研究

专用铁路集装箱江海联运具有较好的经济效益,是铁路运输的重要发展方向。为提升集装箱江海联运的效率,化解既有集装箱江海联运驳接方式的缺点,在阐述既有集装箱江海联运驳接方式及存在问题的基础上,提出专用铁路集装箱江海联运驳接方式,从设施布局、作业流程和实现效果等方面进行分析。专用铁路集装箱江海联运驳接方式可以打破海船与江船的倒装限制,提升集装箱江海联运驳接效率,降低集装箱江海联运成本。     

Network-wide assessment of ATM mechanisms using an agent-based model

This paper presents results from the SESAR ER3 Domino project. Three mechanisms are assessed at the ECAC-wide level: 4D trajectory adjustments (a combination of actively waiting for connecting passengers and dynamic cost indexing), flight prioritisation (enabling ATFM slot swapping at arrival regulations), and flight arrival coordination (where flights are sequenced in extended arrival managers based on an advanced cost-driven optimisation). Classical and new metrics, designed to capture network effects, are used to analyse the results of a micro-level agent-based model. A scenario with congestion at three hubs is used to assess the 4D trajectory adjustment and the flight prioritisation mechanisms. Two different scopes for the extended arrival manager are modelled to analyse the impact of the flight arrival coordination mechanism. Results show that the 4D trajectory adjustments mechanism succeeds in reducing costs and delays for connecting passengers. A trade-off between the interests of the airlines in reducing costs and those of non-connecting passengers emerges, although passengers benefit overall from the mechanism. Flight prioritisation is found to have no significant effects at the network level, as it is applied to a small number of flights. Advanced flight arrival coordination, as implemented, increases delays and costs in the system. The arrival manager optimises the arrival sequence of all flights within its scope but does not consider flight uncertainties, thus leading to sub-optimal actions.