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1.
A key issue affecting the viability and efficacy of intermodal transportation via truck and rail is the operational selection of intermodal ramps. In this paper, two alternatives for ramp selection are examined. Both methods seek to reduce total empty and circuitous miles incurred during intermodal drayage movements. The sensitivity to the ramp group configuration and to freight compatibility is tested to determine the robustness of the findings. The analysis is industrially motivated, using data supplied by J.B. Hunt Transport, Inc. The primary contribution of the paper is in quantifying the performance of the ramp selection methods in various operational settings.  相似文献   

2.
The current literature in the rail–truck intermodal transportation of hazardous materials (hazmat) domain ignores congestion at intermodal yards. We attempt to close that gap by proposing a bi-objective optimization framework for managing hazmat freight that not only considers congestion at intermodal yards, but also determines the appropriate equipment capacity. The proposed framework, i.e., a non-linear MIP and a multi-objective genetic algorithm based solution methodology, is applied to a realistic size problem instance from existing literature. Our analysis indicates that terminal congestion risk is a significant portion of the network risk; and, that policies and tools involving number of cranes, shorter maximum waiting times, and tighter delivery times could have a positive bearing on risk.  相似文献   

3.
We propose a bi-objective optimization framework for routing rail-truck intermodal shipments with hazardous materials, when shippers and receivers have access to alternate intermodal terminals. A tabu-search based solution methodology is developed, which together with the optimization framework is applied to realistic size problem instances to gain managerial insights. Our analysis indicates that drayage accounts for a significant portion of transport risk and that it can be reduced by scheduling direct and faster trains; and, that the mix of intermodal trains depends on the interest of the decision-makers, where the resulting traffic can facilitate planning emergency response systems.  相似文献   

4.
This paper introduces an Agent based modelling approach to model inter-urban freight transport between two or more trading regions. The use of the model is to ascertain the modal share of competing transport modes (road and intermodal) while taking complex transport service supply–demand dynamics into account. It is structured by modules describing company generation, supplier choice, modal competition and International road freight transport market dynamics. The behaviour of individual actors is simulated using normative agent behaviour and market knowledge. Using the micro-simulation approach, shippers and carriers (primarily road hauliers and a maritime based intermodal operator) interact through simulated contracts resulting in the generation of tours. The service performance of the tours is fed back into the model for decision making during contract deliberations. Preliminary application of model to Mediterranean case study show that market share gains of around 25–30% are obtained with policy interventions of financial subsidies to intermodal services and more frequent shipping services in the intermodal transport respectively.  相似文献   

5.
This article deals with an analysis, modeling, and assessing performances of supply chains served by long-distance intercontinental intermodal rail/road- and sea-shipping freight transport corridor(s). For such a purpose, the supply chains are defined and the methodology for assessing their performances under given conditions is developed. The methodology consists of the analytical models of indicators of the operational, economic, environmental and social performances of particular corridors and corresponding supply chains assumed to be dependent on the infrastructural and technical/technological capabilities. The models of particular indicators have been applied according to “what-if” scenario approach to assessing performances of the long-distance intercontinental inland and maritime freight transport corridors spreading between China and Europe in the scope of the “Silk Road Economic Belt” and “A New Maritime Silk Road” policy initiative. The results prove that the intermodal inland rail/road alternative could act as a serious competitive alternative to its maritime deep-sea counterpart under given conditions. Nevertheless, in order to realize the opportunities, large investments in the inland rail/road infrastructure are required to appropriately connect China with Europe.  相似文献   

6.
Intermodalism has become one of the most significant transformations of freight transportation in the United States over the past two decades. The coupling of shipping modes has enabled shippers to more fully realize the respective time and costs advantages of respective modes. The opportunity to take advantage of intermodalism when shipping manufactured goods overseas may provide an essential competitive edge to a company or to an entire region engaged in world commerce. The change in the freight accessibility map of the United States to foreign markets that can be ascribed to intermodal infrastructures and operations has so far not been studied. With the help of a geographic information system, this paper analyzes this transformation in the United States by mapping integral place accessibility measures of five-digit zip code areas with respect to gateways for export of manufactured goods, especially containerized freight. The performance of the intermodal freight network is evaluated by comparing accessibility measures based on the highway network and on the intermodal network, respectively, for all North American container ports, as well as for subgroups of container ports on the Eastern Seaboard, the Western Seaboard, and the Gulf Coast of North America. The paper discusses regional winners and losers in the new national freight transportation system.  相似文献   

7.
A train slot selection model based on multicommodity network flow concepts is developed for determining freight train timetables for scheduling rail services along multiple interconnected routes. The model seeks to minimize operating costs incurred by carriers and delays incurred by shippers while ensuring that the schedules and demand levels are mutually consistent. A column generation-based methodology is proposed for train slot selection to meet frequency requirements. This methodology is embedded in a simulation-based iterative framework, where demand for rail services is re-computed in accordance with the train schedule obtained by solving the freight train scheduling problem.  相似文献   

8.
The paper applies the choice model incorporating attribute cut-offs proposed by [Swait, J.D., 2001. A non-compensatory choice model incorporating attribute cutoffs. Transportation Research: Part B 35 (10), 903–928] to evaluate shippers’ preferences for freight service attributes. A stated preference experiment on a sample of Italian manufacturing firms shows that the marginal utilities of attributes are not constant over the whole range of values presented, and that significant improvements can be made by introducing non-linearities at points specified by individual respondents. It is found that the conventional model overestimates the importance of the attributes, though their relative ranking is maintained. The proposed choice model provides useful information on the difficulty of achieving a modal transfer of freight from road to truck-rail intermodal transport.  相似文献   

9.
Optimizing the aerodynamic efficiency of intermodal freight trains   总被引:1,自引:0,他引:1  
We develop an aerodynamic loading assignment model for intermodal freight trains based on an integer-programming framework to help terminal managers make up more fuel-efficient trains. This is the first use of optimization modeling to address the aerodynamics and energy efficiency of railroad intermodal trains. Several recommendations regarding railway equipment use, operations, and policy are proposed to improve fuel-efficiency and reduce emissions from intermodal transportation. Analysis of one major railroad intermodal route reveals the potential to reduce fuel consumption by 15 million gallons per year with corresponding savings of $28,000,000. Greater benefits are possible through broader implementation of the model.  相似文献   

10.
The dry port concept: connecting container seaports with the hinterland   总被引:4,自引:0,他引:4  
The dry port concept is based on a seaport directly connected by rail with inland intermodal terminals where containers can be dealt with in the same way as if they were in a seaport. The main purpose of the article is to extend the theory behind the dry port concept and to define three dry port categories; distant, midrange and close. The findings show that the dry port concept can help identify ways of shifting freight volumes from road to more energy efficient traffic modes that are less harmful to the environment, relieve seaport cities from some congestion and facilitate improved logistics solutions for shippers in the port’s hinterland.  相似文献   

11.
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.  相似文献   

12.
A generalized shipper transportation cost function is estimated to test whether coal shippers achieve allocative efficiency with respect to market prices when facing limited access to the full range of transportation services. Findings indicate that allocative efficiency with respect to market prices is achieved when shippers have access to all major transportation modes. In contrast, the condition for allocative efficiency is not met with respect to market prices when shippers’ modal choices are limited to trucking and rail services. Findings for the sample of shippers who face limited shipping choices is interpreted as suggesting an over-use of trucks relative to the use of trains due to price distortions of transportation services.  相似文献   

13.
Using a unique data set of individual shipments, port characteristics, and actual freight charges, we examined potential factors within management controls that affect the attractiveness of a port for containerized shipments. We hypothesized that the importance placed on each factor varies by the size of the shipper. We find support for our hypotheses that large shippers emphasize the factors affecting speed of delivery more than the freight charges compared to small shippers. These findings have managerial implications because investments in port development would pay off depending on the fit between the type of investment and the customers’ needs.  相似文献   

14.
We propose a novel model for dispatching trucks given the constraints and sources of uncertainty that arise in drayage operations. The proposed model is designed to minimize the expected cost and is generally applicable to cases including different distributions of random parameters. Numerical examples illustrate this robustness of the model, as well as the potential for reducing the drayage cost by increasing the available storage capacity and permitted number of terminal truck entries. Mathematical results derived within this paper (e.g. expected dwell time) can be used more generally in analyzing transfers in transportation networks under stochastic conditions.  相似文献   

15.
This paper identifies research opportunities which will enable the further integration of inland waterway transport in the intermodal supply chain. Intermodal transport may be interpreted as a chain of actors who supply a transport service. Inland navigation can play a crucial role in increasing supply chain service performance. A first group of research challenges lies in the evolving relationship between transport geography and logistics activities. The next set of research challenges has the objective to encourage efficient operations in IWT: development of a system wide model for IWT, integration of operational planning systems and analysis of bundling networks. A third group of research efforts is directed towards shippers and consignees who use the intermodal transport chain to send or receive their goods: further development of models that integrate intermodal transport decisions with supply chain decisions and creation of green supply chains. A fourth cluster of research challenges concerns the problem domain of external cost calculations. Finally detailed time series data on freight transport should be collected to support these future research tracks.  相似文献   

16.
This paper presents the findings of a stated preference research conducted in Tanzania (East Africa). The objective of the survey was to determine the relative importance as well as monetary values attached to freight transport quality attribute by shippers in this region. In-depth interviews with the logistic managers of companies that produce and ship goods were conducted. The freight transport quality attributes considered in this survey were flexibility, frequency, loss and damage, reliability, and transit time. The monetary values of these attributes have been computed as willingness to pay for their improvement as well as willingness to accept compensation for a decrease in their quality. The results show that shippers in this region consider travel time, loss and damage and frequency as the most important quality attributes. This may have relevant implications for the infrastructural transport policies to be implemented in the country.  相似文献   

17.
This study uses data from a large-scale freight survey conducted in the Tokyo Metropolitan Area to jointly analyze the spatial distribution of logistics facilities and their proximities to the locations of shipment origins and destinations. The aim of the study is to examine in detail the argument that logistics sprawls increase truck trip distances, and thus would incur negative impacts to the society. We found that between 1980 and 2003, logistics facilities in the Tokyo Metropolitan Area have migrated outward, albeit in a much smaller scale than the cases documented in some U.S. and European cities. Our analysis of the shipment data confirms that logistics sprawl increases truck travel. Furthermore, we found that, regardless of their age, logistics facilities tend to increase shipping distances as their distances to the urban center increase, due to the spatial mismatch between the locations of the facilities and the shipment origins and destinations. The findings underscore the importance of comprehensive efforts to coordinate land use, not only for logistics facilities but also other businesses that generate freight movements.  相似文献   

18.
How far can rail freight developments reduce lorry movements and promote sustainable urban distribution when planners discard economically infeasible projects? To expand current dedicated bulk long rail hauls, marginally viable, from Plymouth, UK, potential rail traffics must tap capacity to treble output and cut unit costs. Potentially, aggregated inter-county bulk road movements imply viable train hauls from upgraded railhead facilities. Optimal configurations of enhanced loading, storage and processing facilities and port-railhead links proffer reduced ship demurrage costs with upgraded port handling and relocated petroleum-loading facilities creating employment and further reducing lorry movements. However, in practice, non-viable developments are not sustainable.  相似文献   

19.
This study aims to propose a tangible approach to delimiting the probabilistic hinterland of a port of interest. We first build a geometric model for the probabilistic port hinterland based on intermodal network flows jointly using discrete choice analysis and geographical information of shippers. We further design an algorithm that can efficiently determine the hinterland boundaries using the sample approximation of shippers’ choice probabilities. We provide theoretical results that characterize the minimum computational effort required to achieve a certain degree of accuracy in the sample approximation. We also offer two numerical case studies to justify the proposed approach.  相似文献   

20.
This paper presents empirical estimates of market elasticities of demand and elasticities of mode choice probabilities in the intercity freight transport market. Results are derived from a mixed discrete/continuous choice model of mode and shipment size. The mode choice component of the full model was specified as a binary probit function. The two modes considered were rail and regulated common carriers (full truck load). Data was drawn from the US Commodity Transportation Survey consisting of individual shipments of manufactured goods identified at the most disaggregate level. Results obtained in this study are compared with those obtained in previous studies, and areas of similarities and dissimilarities in the magnitude as well as interpretation of the results are highlighted. The own-price and cross-price elasticities of mode choice probabilities were found to vary from 1.44 to 1.88, and from 1.54 to 1.75, respectively. The market price elasticities of demand were found to vary significantly across commodity groups and geographic territories. Among the 40 market segments considered, the truck price elasticity of demand ranged between −0.749 and −2.525; the rail price elasticity of demand was slightly larger, ranging between −0.956 and −2.489; and the rail–truck cross-price elasticity of demand ranged between 0.904 and 2.532.  相似文献   

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