A Hierarchical and Georeferenced Approach for Freight Terminal Location

1 – Introduction: In transportation, decision-making phase has an essential role in the planning context. The actions of planners have to be efficient and dynamic to generate the best management of the resources and consequently maximize benefits. Recently, the intervening factors became more complex and related to political, economical and social interests, which have to be considered in the final decision. However, transportation decisions have been taken under a limited scope as consequence of the application of methodologies and models . According to Fortes and Paiva , methodologies have been limited to evaluate just travel time and operational costs in a transportation system, which limits and creates incomplete analysis based on cost benefit evaluations. In this sense, as indicated by Hhakee and Stromberg , a new environment with different conditions has made planners realize that new methods exploring computer’s capabilities to simulate complex process are needed. Computational instruments such as the Geographical Information Systems (GIS) can contribute to overcome the limitations observed in decision-making activities. GIS provides a large variety of tools that allow planners to simulate multiple scenarios and to visualize data / results due to its capabilities to process simultaneously attributes and location data related to geographical reality that can be combined with special functions for spatial analysis 4) . Many applications of GIS in transportation studies are noticed in recent years exploring mostly the capacity of storage and visualization associated with modelling techniques. Though such applications have generated several benefits to its users, they did not explore completely GIS potential in the sense that traditional transportation models were not conceived to fully incorporate geographical-spatial data and spatial analysis. Additionally and maybe the most important is the fact that transportation models and GIS are not designed to make planning decisions, although they provide better access and manipulation of the data. In order to combine the information generated by instruments such as GIS and then reach an extensive consideration of the factors influencing the decision-making, some efforts towards the development of Decision Support Systems (DSS) are observed 7) . In these works, it is clearly observed the intention to focus on the evaluation of variables that are not usually considered in transportation analysis through the manipulation of geographical and spatial elements using the framework of decision techniques. Both studies avoid an operation research modelling, which may be implemented without addressing human values and purposeful human activity , concentrating on the management of geographical-spatial information in order to facilitate group-decision. Following the same direction of these efforts, in this paper, we present the development and application of the integration of a decision-making technique (Analytic Hierarchy Process), GIS and Remote Sensing (RS) intending to establish a new approach for the determination of a freight terminal location. This new approach is necessary since traditional location theory is based on a particular hypothesis with a small number of location factors usually related to transport and labour costs, and logistic models just focus on the minimization of distances (costs) in the displacements . In opposition to these conceptions, we propose a hierarchical and georeferenced approach making possible a wider consideration of new variables and the participation of those involved in the decision. In this context, hierarchical stands for the levels of the decision structure using the Analytic Hierarchy Process (AHP), which corresponds to one’s understanding of the situation (goals, criteria, subcriteria and alternatives) , and georeferenced is related to the use of information with a reference in a geographical space, respectively. This paper is divided in four sections. After this introduction (section one), the basic concepts of the AHP-GIS-RS integration are presented in the section two in order to specify the characteristics of each element as well as their role in a decision-making context. Next, we report a case study for the application of the AHP-GIS-RS integration for the location of a freight terminal in Brazil, which is part of a postal transportation system. Finally in section four, it is discussed the relevance of this integration for transportation studies as well as some final considerations are presented.