Freight Carriers Research Articles

Zone pricing for time-definite LTL freight transportation with elastic demand

Because shipments to a pair of administrative divisions are typically delivered with the same time-in-transit service level, shippers expect that they should be charged the same price. Thus, the carrier clusters operation centers located in the same administrative division into a tier-1 zone. These zones are subsequently aggregated into a set of hierarchical zones for which the carrier defines and publishes a zone tariff chart. Zone pricing is a tactical decision that simultaneously determines the zone prices and an operational plan to use its operating capacity to maximize carrier’s profit while meeting the expected service level and operational requirements. We modeled this integral-constrained concave program using link formulation and proposed an implicit enumeration embedded with Lagrangian relaxation upper bounds to determine the optimal prices and operations plan. To meet the shippers’ expectation, we proved our model mathematically and demonstrated computationally, using Taiwan’s largest time-definite LTL freight carrier, that zone pricing has a negative impact on carrier profit in the process of aggregation.

TO STUDY AND FABRICATION OF AIR CUSHION VEHICLE

An Air cushion vehicle is a vehicle that flies like a plane but can float like a boat, can drive like a car but will traverse ditches and gullies as it is a flat terrain. An air cushion vehicle also sometimes called an air cushion vehicle because it can hover over or move across land or water surfaces while being held off from the surfaces by a cushion of air. A Hovercraft can travel over all types of surfaces including grass, mud, muskeg, sand, quicksand, water and ice .Hovercraft prefer gentle terrain although they are capable of climbing slopes up to 20%, depending upon surface characteristics. Modern Hovercrafts are used for many applications where people and equipment need to travel at speed over water but be able load and unload on land. For example they are used as passenger or freight carriers, as recreational machines and even use as warships. Hovercrafts are very exciting to fly and feeling of effortlessly traveling from land to water and back again is unique.

Efficacy of pH elevation as a bactericidal strategy for treating ballast water of freight carriers

Treatment of ship ballast water with sodium hydroxide (NaOH) is one method currently being developed to minimize the risk to introduce aquatic invasive species. The bactericidal capability of sodium hydroxide was determined for 148 bacterial strains from ballast water collected in 2009 and 2010 from the M/V Indiana Harbor, a bulk-freight carrier plying the Laurentian Great Lakes, USA. Primary culture of bacteria was done using brain heart infusion agar and a developmental medium. Strains were characterized based on PCR amplification and sequencing of a portion of the 16S rRNA gene. Sequence similarities (99+ %) were determined by comparison with the National Center for Biotechnology Information (NCBI) GenBank catalog. Flavobacterium spp. were the most prevalent bacteria characterized in 2009, comprising 51.1% (24/47) of the total, and Pseudomonas spp. (62/101; 61.4%) and Brevundimonas spp. (22/101; 21.8%) were the predominate bacteria recovered in 2010; together, comprising 83.2% (84/101) of the total. Testing was done in tryptic soy broth (TSB) medium adjusted with 5N NaOH. Growth of each strain was evaluated at pH 10.0, pH 11.0 and pH 12.0, and 4h up to 72h. The median cell count at 0h for 148 cultures was 5.20×106cfu/mL with a range 1.02×105–1.60×108cfu/mL. The TSB adjusted to pH 10.0 and incubation for less than 24h was bactericidal to 52 (35.1%) strains. Growth in pH 11.0 TSB for less than 4h was bactericidal to 131 (88.5%) strains and pH 11.0 within 12h was bactericidal to 141 (95.3%). One strain, Bacillus horikoshii, survived the harshest treatment, pH 12.0 for 72h.

Estimating order delivery times and fleet capacity in freight rail networks: part I - simulation modelling

We consider an unscheduled rail network with stochastic demand for freight movement between stipulated origins and destinations. Freight orders arrive over time and each order is fulfilled as soon as a locomotive and a rake become available. After transporting an order to its destination, the locomotive and associated rake become available to move new shipments and the dispatcher must determine a suitable resource management policy at this juncture, i.e., whether to hold resources at the terminating junction, or deadhead them to be used at an alternate origin. The dispatcher must also determine if deadheading is to be undertaken reactively, after receiving a request from another station, or proactively, in order to pre-position rolling stock in anticipation of future demand. The amount of deadheading required also depends upon the system resource levels, e.g., rake and locomotive fleet capacities. The determination of the best fleet size and associated deadheading policy to guarantee a given service level (e.g., expected customer order flow time) is a complex operational problem. In this paper, we describe a simulation modelling approach to this problem. Our approach is illustrated using real data from the Indian Railway System, one of the largest freight carriers in the world.

Estimating order delivery times and fleet capacity in freight rail networks: part II - analytic approximation

Rail transit is a critical component of intermodal supply chain networks. We consider the problem of providing order delivery time quotations in an unscheduled rail network, where customers place orders requiring movement of freight between specified origins and destinations. Each order is fulfilled as soon as the required rolling stock, e.g., locomotive and rake, can be assembled at the origin. Estimating an order's delivery time is a complex task, depending upon the available fleet capacity, deadhead policy and the level of congestion present in the network. In this paper, we develop an analytic approximation to estimate delivery time quotations for freight movements, along with required fleet capacity to meet a desired service level. The quality of the analytic approximation herein is validated using a real numerical example from the Indian Railway system, one of the largest freight carriers in the world.

A graph partitioning strategy for solving large-scale crew scheduling problems

Railway crew scheduling deals with generating driver duties for a given train timetable such that all work regulations are met and the resulting schedule has minimal cost. Typical problem instances in the freight railway industry require the generation of duties for thousands of drivers operating tens of thousands of trains per week. Due to short runtime requirements, common solution approaches decompose the optimization problem into smaller subproblems that are solved separately. Several studies have shown that the way of decomposing the problem significantly affects the solution quality. An overall best decomposition strategy for a freight railway crew scheduling problem, though, is not known. In this paper, we present general considerations on when to assign two scheduled train movements to separate subproblems (and when to rather assign them to the same subproblem) and deduct a graph partitioning based decomposition algorithm with several variations. Using a set of real-world problem instances from a major European railway freight carrier, we evaluate our strategy and benchmark the performance of the decomposition algorithm both against a common non-decomposition algorithm and a lower bound on the optimal solution schedule. The test runs show that our decomposition algorithm is capable of producing high-quality solution schedules while significantly cutting runtimes compared to the non-decomposition solution algorithm. We are following a "greenfield" approach, where no information on previous schedules is needed. Hence, our approach is applicable to any railway crew scheduling setting, including network enlargement, integration of new customers, etc.

Adaptative Approach to Implementing Good Practices to Support Environmentally Friendly Urban Freight Transport Management

The fast growth of cities combined with the growing needs of city users, including freight carriers, residents, shippers, trade associations, in turn leads to significant problems with transport coordination and achieving its highest possible efficiency (having taken into account efficient use of loading space, limiting the fleet operation costs, ensuring fast deliveries, etc.). These factors result in the need to search for methods that enable effective implementation of solutions aimed at streamlining and optimising urban freight transport management. All implementation processes may be completed based on three major approaches: developing completely new solutions from scratch – creation, direct copying of practically proven solutions – transfer and transferring practically proven solutions while making changes that mainly depend on the implementation environment – adaptation. The adaptation of good practice makes it possible to avoid mistakes and also to indicate to stakeholders the potential benefits experienced by the cities that have already been using good practice. This paper is focused on a methodology for efficient implementation of urban freight transport (UFT) measures based on the adaptation approach.

Genetic Algorithm-Based Approach for Estimating Commodity OD Matrix

This paper proposes an estimation approach for a commodity origin-destination matrix by using a sample commodity origin-destination (OD) matrix from a Commodity Flow Survey and also mode-specific OD matrices obtained from a transportation record of freight carriers. The proposed approach is formulated as a multi-objective bi-level optimization problem in which the upper-level seeks to minimize the sum of square deviation from the target matrices, while in the lower-level, user-equilibrium assignments of commodity OD matrix from a CFS and mode-specific OD matrices are performed. The developed model and the Genetic Algorithms-based solution algorithm were validated and tested on an intermodal transportation network of Korea. The results show that the model is able to produce an acceptable commodity OD matrix, implying that the proposed approach is applicable for a real-world problem.

Application of exact route optimization for the evaluation of a city logistics truck ban scheme

This paper presents an application of the exact solution approach for the Vehicle Routing Problem with Soft Time Windows based on the column generation scheme developed earlier by the authors, for evaluating a truck ban scheme from the environmental improvement aspect on a realistic logistics instance based on the Vehicle Information and Communication System data, which is an Intelligent Transportation Systems (ITS) application in Japan. Two different types of truck ban schemes are evaluated, one which denies truck entry on congested links (with average speeds lower than a threshold) and the other with and without the availability of the ITS-based data to freight firms. It was found that the Uniform truck ban on low travel speed links can result in a win-win situation, improving the environmental conditions as well as reducing the operation cost for freight carriers in a scenario where freight carriers do not have access to ITS-based travel time information. While the use of an exact optimization method and with ITS-based historical traffic information still helps in reducing environmental impacts, freight companies are slightly worst-off as far as the operation cost is concerned.

Joint operational decision-making in collaborative transportation networks: the role of IT

Purpose– This paper addresses horizontal supply chain collaboration among autonomous freight carriers in the less-than-truckload industry. The main purpose of the paper is to identify and explain the challenges with joint operational decision-making in this context and investigate the precise role of information technology (IT) therein.Design/methodology/approach– Empirical evidence is gathered by means of exploratory and explanatory case research, with multiple cases at the planning departments of European freight carriers operating in collaborative transportation networks.Findings– Collaborating carriers face fundamental challenges in joint operational planning and control of collaborative transportation, despite the broad availability of state-of-the-art IT. These operational supply chain challenges can be explained by technological differences of the available IT applications, which hinder integration.Research limitations/implications– Any expectations with regard to state-of-the-art XML or EDI-based IT integration for improved joint operational decision-making in collaborative transportation networks should be considered with care. In particular, the authors' research findings may encourage practitioners to consider new planning and control procedures and develop dedicated IT applications for collaborating freight carriers.Originality/value– The paper highlights the importance of horizontal supply chain collaboration for small and medium-sized freight carriers in the less-than-truckload industry and conceptualises how collaborative transportation networks are organised. Furthermore, an IT typology is introduced to explain the challenges with joint operational decision-making.

Finding Efficient and Environmentally Friendly Paths for Risk-Averse Freight Carriers

This paper aims to incorporate two important measures into a freight shortest path problem, namely reliability and sustainability. Reliability measure deals with the uncertainty of link travel time while sustainability measure tends to reduce the fuel consumption and emission along the path. Greenhouse gas (GHG) emission rates are generated from Motor Vehicle Emission Simulator (MOVES) model and approximated as a function of the average link travel speed. To model uncertainty, the link travel speed is treated as a discrete random variable with a given distribution. Freight carriers are assumed to be risk-averse; for example, given two paths with the same average cost, carriers prefer the one with less variability. The risk-averse behavior is captured by the second order stochastic dominance (SSD) relationship. Specifically, SSD constraints are introduced in our model to narrow down the feasible paths which dominate a chosen benchmark path. The reliable and sustainable routing model is formulated as an integer program that can be easily tailored to a variety of modeling preferences. The study experiments with eight variants of the base model, each corresponding to a different trade-off strategy between three objectives, namely, efficiency, reliability and sustainability. The numerical experiments illustrate the benefits of the models discussed in the paper.

DESIGNING COCOA TRANSPORT NETWORKS USING A SUPPLY CHAIN NETWORK EQUILIBRIUM MODEL WITH THE BEHAVIOUR OF FREIGHT CARRIERS

This paper presents a multi-channelled supply chain network equilibrium (SCNE) model with the behaviour of freight carriers, which is developed to represent the trading chain of cocoa in Sulawesi, Indonesia. The model takes into account the behaviour of local collectors, local traders, exporters, and freight carriers. Utilising this SCNE in the lower level, a combinatorial optimisation is undertaken in the upper level within the framework of mathematical programmes with equilibrium constraints, where a suitable set of transport network improvement actions is selected from a number of possible actions for improving the efficiency of cocoa supply chain network (SCN). The upper level is solved with a modified probability- based discrete binary particle swarm optimisation. Finally, the model is applied to an actual cocoa SCN in Sulawesi for investigating the impact of transport measures to the international trading of cocoa.

Vehicle Routing under Consideration of Transhipment in Horizontal Coalitions of Freight Carriers

In order to reduce operational costs related to transportation activities in road haulage, small and medium-sized freight carriers can establish horizontal coalitions and share their resources. Through exchange of customer requests with other members within the coalition, carriers can improve the operational efficiency of their transportation processes. In this paper, transhipment is integrated into the conventional pickup and delivery problem in the collaborative context. Specifically, vehicles involved in transferring the same request are synchronized at the transhipment points. A mixed-integer programming model is proposed for this problem. Based on this model the benefits of transhipment are analysed. Computational results show considerable cost-savings enabled by transhipment in the operational planning of carrier coalitions.

Practices of using weigh-in-motion technology for truck weight regulation in China

Trucks exceeding legal axle and gross vehicle weight limits can bring severe damage to infrastructure and increase the risk of traffic crashes. It is therefore important to ensure that freight carriers comply with weight regulations. This paper provides a comprehensive review of how weigh-in-motion (WIM) technology has been used to improve the truck weight regulation in China. In particular, a toll-by-weight method is introduced for trucks using toll roads. Compared to the conventional vehicle class based toll structure, the toll-by-weight method establishes a fair fee structure that prevents overloaded trucks from taking advantage of non-overloaded trucks. It also allows freight carriers the flexibility of moderate overloading by paying higher toll rates. This paper further proposes a mechanism of integrating toll-by-weight with effective weight enforcement for truck weight regulations. It encourages overloaded trucks to use toll roads instead of vulnerable non-toll roads, and helps to generate additional much needed revenues by local governments for highway construction, maintenance, and truck weight enforcement. In addition, technical and managerial problems affecting the applications of WIM are pointed out in this paper. Finally, perspectives on future WIM development and adaptions of other advanced technologies for truck weight regulations are presented.

A Global Freight Business Ecosystem Based on Low Carbon End-to-End Transport and Logistic Services

In this paper the authors present the global freight business ecosystem of the iCargo Integrated Project, that aims at advancing and extending the use of ICT to decarbonize co-modal logistics by enhancing intermodal transport reliability and optimizing environmental performances. iCargo users represent organizations involved in the provision of door-to-door low-carbon logistic services, covering an entire supply chain or a significant portion of it, producing less than alternatives, making use of the iCargo ecosystem to combine services through different transport modes and providers. The iCargo ecosystem actors are clients, like manufacturers and retailers, logistic services providers, including freight forwarders and carriers for the different transport modes, and providers of support services, ensuring access to physical and information infrastructures. The iCargo ecosystem foresees a common representation of door-to-door services with a decentralized architecture. The distinctive elements of the iCarg...

Collaborative transportation planning of less-than-truckload freight

Collaborative transportation planning (CTP) within a coalition of small and medium-sized freight carriers can be used as a powerful instrument to improve the operational efficiency of the coalition members. In such coalitions, transportation requests from different carriers are exchanged in order to reduce the total fulfillment costs. In this paper, the CTP for a set of independent carriers exchanging less-than-truckload transportation requests is considered. The realistic restriction that all collaborating partners have only limited capacities in their fleets is included in the consideration. To keep their autonomy, coalition members keep their sensitive information including customer payments and cost structures unexposed during CTP. A new decentralized request exchange mechanism for CTP is proposed while only vehicle routes are considered for exchange. It is tested on some newly generated instances and the CTP solutions are compared with those obtained by isolated planning without collaboration and those obtained by a heuristic approach for the centralized planning problem. The results indicate that our mechanism is very efficient and effective in terms of realizing potential cost-savings by CTP, even when capacity limitations and restrictions on the exposure of information are explicitly considered.

Service parts inventory control with lateral transshipment and pipeline stockflexibility

In equipment-intensive industries such as truck, electronics, aircraft and dredging vessel manufacturing, service parts are often slow moving items for which the transshipment time is not negligible. However, this aspect is hardly considered in the existing service logistics literature. In this paper, we consider this aspect and propose a customer-oriented service measure which takes into account pipeline stock and lateral transshipment flexibility. We provide an approximation method for optimizing the stock allocation subject to this service measure. Via extensive numerical experiments, we show that our approximation performs very well with respect to both system performance and costs. Moreover, our numerical experiments indicate that including lateral transshipments and pipeline stock flexibility in inventory decisions is more beneficial than lateral transshipments alone. This effect is larger for high demand rates and high lateral transshipment costs. Results from a case study in the dredging industry confirm our findings. We therefore recommend introduction of pipeline stock information such as the track and trace information from freight carriers in existing ERP systems.

The impact of collaborative backhaul routing on carbon reduction in the freight industry

The study investigates a practical freight carrier collaboration problem in a carbon-constrained business context. It examines to see if collaboration between carriers can reduce the environmental issues of freight movement. The introduction of carbon credit systems will stimulate freight carriers to decide whether it should trade carbon credits with its collaborators. This issue is examined by formulating the problem as a two-stage stochastic program to minimize the joint emission of the carriers while meeting their service commitments. The collaborative model developed can reduce emissions across a freight network by 3–20%.

Revenue management in road-based freight transportation

Purpose – Freight carriers operating in a spot-market environment are faced with uncertain future capacity demand, actual revenues, and properties of freight items. They require information about the expected future consumption of limited capacity to derive suitable request acceptance decisions. The purpose of this paper is to present a new idea to improve the handling of inaccurate information on the weight and volume of upcoming requests. Design/methodology/approach – The authors start with the definition of a new mathematical optimization model as the backbone of a capacity control system. This model is embedded within a rolling-horizon decision-making process involving consecutively arriving requests. Computational simulation experiments are carried out to evaluate the applicability and efficiency of the proposed decision support system. The authors investigate how the new model contributes towards keeping the negative impacts of inadequate forecasts of the expected volume of future requests as low as possible. Findings – In traditional application fields of capacity control (airline ticketing or hotel reservations) the physical extent of a request is always 1 (set/bed/room). In road-based freight transportation the variety of the physical extent of requests is much more complicated and complex. The major finding is that existing capacity control approaches are unable to meet the special requirements of road-haulage. Innovative capacity control features are necessary in order to cope with the higher request portfolio complexity. Originality/value – This paper addresses the requirements of a capacity control system for road-based freight transportation. An innovative decision support system is evaluated. For the first time, the authors present a comprehensive quantitative simulation study dedicated to this complicated decision-making situation.

Price and frequency competition in freight transportation

This paper develops a simple analytical model of price and frequency competition among freight carriers. In the model, the full price faced by a shipper (a goods producer) includes the actual shipping price plus an inventory holding cost, which is inversely proportional to the frequency of shipments offered by the freight carrier. Taking brand loyalty on the part of shippers into account, competing freight carriers maximize profit by setting prices, frequencies and vehicle carrying capacities. Assuming tractable functional forms, long- and short-run comparative-static results are derived to show how the choice variables are affected by the model’s parameters. The paper also provides an efficiency analysis, comparing the equilibrium to the social optimum, and it attempts to explain the phenomenon of excess capacity in the freight industry.