Distribución óptima del transporte intermodal: aplicación a la exportación de perecederos

[EN] This paper discusses the benefits using intermodal transport for fruit and vegetables. Multi-Criteria Decision Making techniques are applied for optimal allocation between land or intermodal transport. Also a sensitivity analysis is made for knowing changing priorities in decision-makers (exporters) to encourage a modal shift. The results show savings in intermodal transport costs in relation to land transport cost. However the exporter must assume increased time of delivery of goods.[ES] Este trabajo analiza los beneficios derivados del uso de la intermodalidad del transporte en el sector exportador de frutas y hortalizas, entendida como el empleo del transporte marítimo de corta distancia combinado con el tráfico por carretera. Se aplican técnicas de decisión multicriterio para realizar una distribución óptima entre la opción terrestre y la intermodal. También se realiza un análisis de sensibilidad que cuantifica los cambios de prioridades que tendrán que producirse en los decisores (exportadores) para motivar un cambio modal. Los resultados muestran que el empleo intermodal conlleva un ahorro en el coste de transporte; como contraposición el exportador debe asumir un aumento del tiempo de entrega de la mercancía.Este trabajo ha sido financiado parcialmente por el proyecto Redymar (P10/08) del Ministerio de Fomento y los fondos del MCINN y FEDER: proyectos ECO2008-02258 y ECO2008-03445.Pérez-Mesa, JC.; Salinas Andújar, JA. (2011). Optimal distribution of intermodal transport: Application to perishables exports. Economía Agraria y Recursos Naturales - Agricultural and Resource Economics. 10(2):93-119. https://doi.org/10.7201/earn.2010.02.05SWORD9311910

A Mixed Integer and Multiple Objective Programming Model to Analyze Coal Handling in New England

Mandated electric generation coal conversions in New England could place a severe strain on the coal handling and transportation facilities in New England ports. This paper presents an analytical scheme leading to the development of optimal plans for the reuse and redevelopment of marine transport networks in New England. Utilizing the port inventory that provides information on existing coal handling facilities and the capability of the ports to increase capacity of existing facilities or locating new facilities, a mathematical programming model is used to determine the optimal capacity, placement and railrod and marine interface of coal handling facilities within and between the New England ports and converting power plants. Initially a mixed integer programming model with a least cost objective is formulated. It is then expanded to a multiobjective programming problem in order to provide information to the port planners and decision makers on the tradeoffs between the costs and temporal efficiency of coal transporation and handling for various locational configurations. © 1983

The Impact of Coal Conversions on the Ports of New England

Historically, waterborne movements of coal into the New England regions were very important. This paper presents the results of a systematic study of the transportation of coal into the region to satisfy the anticipated energy demands of the electric utilities. The results of this analysis indicate that waterborne movements of coal can once again predominate. Even with the added investments necessary for the construction of new coal handling equipment at the ports of New England and the costs associated with additional coal transfers, water modes tend to be the most economical. The ports of Providence and Boston appear to have some geographical strategic importance to this coal trade.-Author

Modeling U.S. Coal Export Planning Decisions

This paper develops a network-optimization planning methodology for U.S. coal port infrastructure. The model analyzes the economic and geographic impacts of harbor deepening and offshore topping-off, improvements which are considered essential for the U.S. to maintain export levels in the face of lower-cost competition because they enable loading of the largest coal supercolliers. The Coal Logistics System (COLS) is a mixed-integer programming model that captures the interaction between coal types and origins, rail and barge networks, ports and intermodal terminals, economies of scale in ocean shipping, foreign demand for steam and metallurgical coal, and environmental regulation. Model results provide the optimal set of coal flows for minimizing the costs of producing, transporting, and transshipping coal. A base case is calibrated for 1985 in which the model predicts the throughput at each of five major ports within 10 percent of actual historical levels. Four scenarios evaluate the effects of dredging at Baltimore and Norfolk harbors and of an offshore topping-off facility in Delaware Bay on the basis of systemwide cost savings and interport competition. Scenario results indicate that coal traffic alone is sufficient to justify the channel deepening work recently completed at Norfolk or underway at Baltimore, but perhaps not both. The alternative of offshore topping-off of light-loaded supercolliers merits further study. The research demonstrates the applicability of optimization models for analyzing marginal supply regions, geographic and product competition, intermodal competition, competition for port forelands, traffic diversions between port hinterlands, and concentration of traffic. © 1991, Taylor & Francis Group, LLC. All rights reserved

Optimizing Freight Transshipments: An Evaluation of East Coast Coal Export Options

Many factors will determine the extent to which the U.S. will be a significant supplier of coal to world markets. Important among these factors is the ability of the domestic coal transport system to move coal from mines to export ports and the capability of these ports to efficiently transship the coal to export markets. This paper describes the use of a mixed-integer mathematical programming model, called the Coal Logistics System (COLS), to provide information for transportation infrastructure planning with regard to increasing U.S. coal exports. COLS is a comprehensive coal transportation model that includes the location and activity levels for coal handling technology. It is used in this study to evaluate potential patterns of export coal movements in the Eastern U.S. with respect to transportation costs, optimal location and activity levels for port coal handling facilities and related investment expenditures. © 1983

Mexican natural gas implications for the US market

Despite the current glut of natural gas in the USA, much future demand may not be met unless supplementary sources of supply are developed. Mexico is not now an important supply source but a September 1979 agreement may mean that large volumes of Mexican gas will be exported to the USA in the future. This paper presents a modified version of the out-of-kilter algorithm used to examine the possible impacts of this gas, with particular attention given to identification of those areas most likely to benefit from these supplemental supplies. The results indicate that if Mexican natural gas is introduced to the US pipeline network in either southern Texas or southern New Mexico in large quantities, serious pipeline capacity problems may inhibit the use of Mexican supplies as a supplementary source

A Dynamic Location‐Allocation Model for Evaluating the Spatial Impacts for Just‐in‐Time Planning

This paper presents an interperiod network storage location‐allocation (INSLA) model to solve the just‐in‐time production planning problem. The model is extended to a multiobjective problem in which trade‐offs between delivery time and transportation costs are analyzed. The results for a hypothetical problem show that in an attempt to reduce inventories on the part of the primary purchaser of raw materials, the possibility exists for less than optimal behavior in the system. 1990 The Ohio State Universit

Measuring the Vulnerability of Populations Susceptible to Lead Contamination in the Dominican Republic: Evaluating Composite Index Construction Methods

There are several suspected sources of lead contamination in the Dominican Republic (DR) to which populations, to a greater or lesser extent, may be exposed. These sources include: a lead battery recycling plant, a gold mine and vehicles using leaded gasoline. In this paper we create and compare indices of spatial vulnerability using different index construction methods including: the weighted average, ordered weighted average, and Data Envelopment Analysis. The vulnerability attributes used to create these indices include: exposure to lead effluents in water from the gold mine as measured by distance from potentially contaminated water, point source lead air emissions from the battery recycling plant estimated by air plume analysis; and mobile source exposure to lead emissions from road transportation measured by potential traffic impacts. The intensities of vulnerability to lead of the towns and cities in the DR, produced by each of the different index construction methods, are compared and evaluated. © 2011 Springer Science+Business Media B.V

An Interperiod Network Storage Location-Allocation (INSLA) Model for Rail Distribution of Ethanol Biofuels

In response to the US federal renewable fuels standards, new ethanol plants of varying sizes are being established in the US. The transportation challenge is to decide on how best to move raw materials to these existing and new ethanol plants, and to ship the fuel from the ethanol plants to markets around the country. In this paper, we extend the Interperiod Network Storage Location-Allocation (INSLA) model formulation into a Rail-INSLA model to address the transportation/transshipment issues associated with the rail distribution of ethanol biofuels that include: transporting less than unit train quantities from each plant, developing new sidings at ethanol plants to accommodate a unit train, and determining the optimal number and locations for carrier operated terminals for the agglomeration of less than unit train size shipments into unit train shipments. © 2009 Elsevier Ltd