A less-than-truckload carrier collaboration planning problem under dynamic capacities

This paper addresses the deterministic dynamic single carrier collaboration problem for the small- to medium-sized less-than-truckload (LTL) industry. It is formulated as a binary (0–1) multi-commodity minimum cost flow problem and solved using a branch-and-cut algorithm. Its inherent network structure is exploited to generate the lower bounds to the branch-and-cut algorithm using the network simplex method and by relaxing the integrality constraints. Results from numerical experiments indicate inherent trade-offs at the higher degrees of collaboration between waiting for more affordable collaborative capacity and incurring higher holding costs. They also suggest that collaborating LTL carriers experience increased capacity utilization.     

Regional policy issues for rail freight services

This paper presents some of the results of the shortlines research project for Ademe (French agency for the environment) and Predit (French support program for surface transport research). The paper focuses on France, and makes some comparisons with North America and Germany. It is organized in two parts. The first part analyses the notion of “short line” freight railways in the European context. We observe that to date, unlike short lines in North America, which have mostly sought cooperation with major railways, the new rail operators in Europe are competing with the majors. The second part discusses regional policies on rail freight transport. We observe that for some time, local governments in France have been afraid that the on-going reduction of regional rail freight services will increase truck traffic and environmental impacts. Today, however, these governments appear to be more reluctant to promote rail freight activities than they were a few years ago. The current conditions under which local lines operate in Europe and especially in France, including small capacity on the infrastructure and high cost of labor and low productivity, may explain this reluctance.     

Modeling net rates for expedited freight services

We demonstrate the development, testing and application of statistical models to study actual billings (net of discounts) for expedited freight services. The models reveal the structure of net tariffs. They enable carriers to identify customers whose revenues are deficient considering services rendered, and terminals where revenues are deficient considering their mix of business. The models thus point to situations where business activities, pricing structures or negotiated discounts need review. The models also verify that the overwhelming determinants of monthly charges to shippers are the fundamental cost drivers for the industry, namely number of shipments, weight of shipments, and distance shipped.     

Routing design for less-than-truckload motor carriers using Ant Colony Optimization

One of the most important challenges that confronts less-than-truckload carriers serving many-to-many distribution networks consists of determining how to consolidate flows of small shipments. The objective is to determine a route for each origin–destination pair that minimizes the cost while still guaranteeing a certain level of service. This research studies different aspects of the problem and provides a metaheuristic algorithm (based on Ant Colony Optimization techniques) capable of solving real-life problems in a reasonable computational time. The viability of the approach has been tested with a real case in Spain and encouraging results have been obtained.     

The potential of horizontal collaboration in airport ground freight services

Since the global economic crisis of 2007–2011, the increasingly dynamic and challenging air cargo market in Europe has forced freight forwarders to improve their performance. In addition to improving their internal transport efficiency, they have also started to look at previously unexplored opportunities for horizontal collaboration in landside airport transport. The aim of this study is to reveal the potential of air cargo transport collaboration on a horizontal level, i.e. between multiple freight forwarders within a single airport. Reviewing existing literature on horizontal collaboration, with a focus on the air cargo industry, we propose a conceptual framework for transport collaboration in the air cargo industry. Based on a comprehensive study on air cargo transport movements within Schiphol, using a simulation model based on company data of 10,747 shipments (6977 tons of cargo) for a period of 30 days, we find several interesting results. Our main finding is that horizontal collaboration can improve the transport performance, by maintaining a high frequency of transport movements and maintaining an acceptable throughput time for air cargo shipments, and at the same time reduce transport costs by up to 40%. For smaller freight forwarders, the frequency of transport deliveries can even increase, while still allowing them to improve the average load factor of transport movements.     

Stopover and hub-and-spoke shipment strategies in less-than-truckload carriers

This paper presents a methodology to identify when freight consolidation strategies are cost-efficient in the less-than-truckload carriers operations. Shipments are assigned based on proximity and cost criteria to build an initial long-haul shipment solution. This initial solution is later improved by the implementation of Tabu Search algorithm. The proximity criterion takes into account the spatial distribution of shipments loads among centers. The results show that the proposed methodology may reduce the transportation cost by 20% compared to the solution of those heuristics only considering cost criterion.     

A multi-objective genetic algorithm approach to design optimal zoning systems for freight transportation planning

This paper contributes to the existing research on freight transportation, spatial and land use planning by investigating an improved spatial aggregation technique to delineate desirable freight traffic analysis zones. Zoning is a process of spatially aggregating several predefined basic spatial units (BSUs) into multiple zones. It plays a vital role in the transportation planning and decision-making process and is well-documented as the modifiable areal unit problem (MAUP). MAUP involves aggregating BSUs to obtain optimal zones satisfying specific criteria and constraints. This paper proposes an improved spatial aggregation methodology to develop a freight traffic analysis zone system by applying the multiobjective optimization concept using a genetic algorithm. The decision variables, namely, (i) Freight trip density; (ii) Number of establishments; (iii) Employment density; and (iv) Compactness, are chosen to represent the elements of freight, passenger traffic, and land use. The problem is formulated as a multiobjective network partitioning problem. The four objectives aim to create zones with better homogeneity and compactness. It is solved using a genetic algorithm with a weighted distance metric approach to prioritize the four objectives. Results show that zones resulting from the improved methodology are superior to the existing zones in terms of homogeneity of decision variables and compactness. The findings are expected to help the decision-making process of urban, transportation, and land-use planners in selecting appropriate freight traffic zone delineation strategies for a given region.     

适应现代物流理念的合肥铁路枢纽货运站布局规划

运输市场竞争的加剧,要求铁路货运业务必须向现代物流服务转变。结合合肥经济、交通发展现状及规划,提出了完善优化合肥铁路枢纽货运站布局、合肥综合性货运站搬迁的必要性,对物流化合肥铁路枢纽货运站选址的原则、方案及结果进行详细分析。     

The dynamics of modal split for freight transport

The paper presents a dynamic model of modal split in a multimodal freight transport system, which supposes that the evolution over time of transport demand is accompanied by a corresponding evolution of transport modes, and that users react with delay to cost variations. Starting with these hypotheses, and following the paradigm of random utility, a recursive equation is obtained, whose iterated application furnishes the sequence of the demand fractions on the various transport modes in the successive epochs of the time period during which the evolution of the transport system is studied and enables forecasting the future modal split evolution.     

Pricing freight rate options

In this paper we set up the theoretical framework for the valuation of the Asian-style options traded in the freight derivatives market. Assuming lognormal spot freight dynamics, we show that Forward Freight Agreements (FFA) are also lognormal prior to the settlement period, but that this lognormality subsequently breaks down. We suggest approximate dynamics in the settlement period for the FFA that leads to closed-form option pricing formulas for Asian call and put options written on the spot freight rate indices in the Black [Black, F., 1976. The pricing of commodity contracts. Journal of Financial Economics 3, 167–179] framework. In a Monte Carlo experiment we show that our formula gives very accurate prices, in particular for forward-starting freight options.     

做好铁路货运中心的规划与设计更好地适应物流产业和社会发展要求

铁路发展不仅仅在客运方面,重载和货运也在发展。铁路货场是最常见、最基础的铁路设施,也是站场设计最基本的技能。货场布置形式多年来没有太大的变化,自从集装箱结点站开始建设后,在铁道部领导的指引下,开始树立整列进出货场的新理念,此后发展战略装车点,进一步推动了铁路货场设计方式的变革。随着那曲物流中心的建设,为铁路货场设计理念的转变创造了实践和应用的条件。此后,在厦门、成都、贵阳、重庆、昆明、银川、南宁等地结合枢纽改扩建、优化整合既有货场设施,以及调整客货布局,新建了新一代铁路货运中心。结合这些货运中心的建设,谈谈铁路货运中心发展的前景与设计中的一些方法。     

The non-bulk market for rail freight in Great Britain

An increased role for rail freight is an objective of the British government. Limited growth potential exists in rail’s traditional bulk markets, so more non-bulk volume is needed. This paper focuses on non-bulk rail freight activity in Britain, through desk-based research and company interviews. It considers changes in both the intermodal and traditional less-than-trainload (LTL) markets over the last decade. Issues relating to the use of these two types of services are presented, covering the principal opportunities and major constraints. Growth potential for both intermodal and traditional LTL flows is identified, but success is dependent upon important pre-requisites being satisfied.     

An inventory-based simulation model for annual-to-daily temporal freight assignment

In the aggregate freight demand modeling literature, temporal assignment (annual to daily flows) is often oversimplified or neglected altogether. Unlike passenger flows, freight flows over the course of a year are not uniform and can vary significantly as the result of trade-offs between inventory and transportation cost management. We introduce the first temporal assignment model that explicitly considers these trade-offs for aggregate freight forecasting. A two-stage model is proposed that first decomposes aggregate annual zonal flows to firm group annual flows using a supply chain network model, which are then temporally assigned by simulating purchase order transactions throughout supply chains. Lot sizes are estimated with an Economic Order Quantity (EOQ) model and calibrated with monthly inventory data. The result is an aggregate-disaggregate-aggregate model that fits into aggregate freight forecasting models but makes use of more disaggregate logistical data. The model is illustrated with a simple replicable example, followed by a case study conducted with California statewide data to break out the distributed zonal flows into average daily volumes for network assignment. Calibration results using 2007 IMPLAN data showed a median percentage difference of simulated annual flows from FAF³ data of 2.38%, and a median percentage difference of simulated inventories from IMPLAN data of 4.85%, which suggests an excellent fit. Empirical validation results showed the model outperforms fixed factor approaches in mean value accuracy by 15–31%.     

A meta-model for passenger and freight transport in Europe

On the basis of the outcomes of five disaggregate national models for passenger transport, four national models for freight transport and two European transport models, a fast and approximate meta-model for passenger and freight transport in Europe has been developed. The meta-model for passenger transport includes a detailed segmentation of the population, which makes it possible to investigate the impact of policies on many different groups of the population. The meta-model for passenger and freight transport has been applied for a reference scenario for 2020 and to simulate many elements of the European Commission's Common Transport Policy. These policy measures were also assessed in terms of the consequences on the internal and external cost of transport.     

Nonlinear inverse optimization for parameter estimation of commodity-vehicle-decoupled freight assignment

A systematic approach to estimate parameters from noisy priors is proposed for traffic assignment problems. It extends inverse optimization theory to nonlinear problems, and defines a new class of parameter estimation problems in the transportation literature for networks under congestion. The approach is used to systematically calibrate a new link-based variation of the STAN model which decouples commodity flows and vehicle flows. The models are tested on a small network and then a case study with real data from California statewide implementation. Cross-validation shows 15% CV of the RMSE.     

Port choice and freight forwarders

In light of the growing supply chain power of 3PLs and very limited empirical studies on port choice from the freight forwarders’ perspective, this paper tries to evaluate the major factors influencing port choice from the Southeast Asian freight forwarders’ perspective, their decision-making style and port selection process and draw out some policy implications for port operators and authorities. Efficiency is found to be the most important factor followed by shipping frequency, adequate infrastructure and location. Their selection process is complex and a two-stage process and supports the new approach that models ports within the framework of a supply chain.     

Shift designs for freight handling personnel at air cargo terminals

This paper presents an integrated mixed integer linear programming (MILP) model for determining manpower requirements and related personnel shift designs for the build-up and break-down of the unit load devices (ULDs) at the air cargo terminal to minimize manpower costs. To utilize the manpower resources efficiently, we implement a new mechanism for demand leveling. In addition, we consider the qualification hierarchy between build-up and break-down workers. A case study based on the real-life data shows that the model is useful for manpower planning at air cargo terminals and the integrated approach is far superior to a traditional two-stage approach.     

Searching for policy priorities in the formulation of a freight transport strategy: a canonical correlation analysis of freight industry attitudes

An efficient and effective freight transport strategy can be aided by early professional contributions from key stakeholders. One broad group who have historically been given limited opportunity to influence the drafting of a freight strategy, are commercial road users and shippers who manufacture and distribute goods. Utilising a data set collected in Australia in 1996 from a sample of organisations involved directly and indirectly in road freight transportation, views were sought on road infrastructure changes, new road infrastructure, non-road infrastructure needs and transport policies. An optimal scaling approach using non-linear canonical correlation is implemented to search for structural relationships between the underlying policy and infrastructure dimensions and the various industry categories. This framework provides a powerful mechanism for identifying differences among stakeholders in terms of their support for or opposition to specific policies. Results reveal the considerable differences in attitudes associated with the component parts of the freight industry.     

Allocating collaborative costs in multimodal barge networks for freight bundling

In order to improve the competitive position and efficiency level of multimodal transport, consolidation of freight flows is often suggested. Bundling networks require cooperation between multiple partners in the multimodal transport chain. In this context, the question rises how benefits may be allocated fairly among the spatially distributed participants in the cooperation. A great deal of scientific literature reports on the behavior of allocation methods in collaborations between shippers or carriers making use of unimodal road transport. However, research on cost or savings allocation methods in multimodal transport is scarce. The main contribution of this paper is thus to provide a first insight in the complexity of sharing cost savings fairly among shippers who bundle freight flows in order to reach economies of scale in multimodal barge transport. By applying four different allocation methods to two realistic case studies, a comparison is made between simple and straightforward allocation mechanisms and more advanced techniques based on cooperative game theory. Special attention is paid to the savings division among coalition partners and collaborative stability. Results demonstrate the influence of cooperation characteristics on allocation outcomes and underline the value of carefully selecting appropriate allocation mechanisms when long-term stability of the multimodal barge collaboration is aspired.     

Interregional trade network analysis for road freight transport in Greece

This paper suggests a flexible decision support framework for the strategic planning of a freight transport hub network in Greece. The proposed methodology treats practical aspects related to the optimal number, location and geographical covering of hubs, through the network analysis of interregional trade, based on original survey data for road freight flows during 2004–2012. The results offer insights into the hierarchical structure of the network and related investment priorities, as the hub role of a prefecture is found to be strongly influenced by high population densities and manufacturing specialization, and its location along highway corridors.