The use of topological indicators in the analysis of communication networks. Essay on the road network of Catalonia

Abstract

This article summarizes the results of the application of topological indicators to the analysis of the road network of Catalunya. The concepts of geographical centrality and accessibility have been contrasted as a means of measuring the spatial heterotrophy resulting from the form and characteristics of the road network. The relative accessibility of different settlements has been used as a basis for establishing a matrice of potencial interactions among different parts of the region, which, in turn, bears an influence on the localization of economic activities.

The study does not attempt to structure the relationships of this potential in order to assess the degree of influence of relative accessibility on the evolution of the regional economy. It attempts exclusively to demonstrate the suitability of geographical methods for studying and planning road network, in contrast to conceptually biased methods of dubious value based on traffic demand, methods which have been so widely used in this country over the last decade.

This article consist of:(a) a methodological outline of the study, (b) a description of the road network, (c) the selection of the sectors of the network to be evaluated through the chosen indicators, (d) the structuring of the graph and its associated matrices, and (e) its application to the analysis of the spatial variations in settlement distribution in Catalonia. Some of the alternative actions projects proposed by various public and private authorities are also described, and a comparative analysis of their effects on the relative accesibility of the vertices of the network is made. A comparison of inversion costs to the demographic and spatial repercussions of this accessibility makes it possible to establish a hierarchy of projects, and estimate their relative contribution in reestablishing territorial equilibrium in Catalonia.