Making Accessibility Visible: Visualizing Spatial Accessibility Through Multi-Dimensional Scaling Model

Abstract

Accessibility has progressively claimed a central role in policy discourse and planning in the Global South. However, availability of approaches for its assessment is still limited in practice. Multidimensional Scaling (MDS) is a statistical tool aimed at explaining relations of distances, such as the analyzed in accessibility, through the construction of a new space of projections. That way, results are easily visualized and interpreted. Our research explores the use of MDS for the visualization of spatial accessibility. Taking the cities of Pereira and Dosquebradas, which belong to the Metropolitan Area of the Centre-West (MACW) of Colombia, we calculate the shortest path from each intersection to the rest assuming trips in motorized and non-motorized transport modes. This approach allows to visually re-configure the spatial distribution of intersections in the transport network, graphically representing accessibility levels for different zones in the metropolitan region of analysis. The use of MDS enables a more intuitive interpretation of accessibility and the exploration of underlying factors that can influence spatial inequalities, as well as to visualize changes generated by different transport and land-use interventions. Results allow to visualize the configuration of the two municipalities in the metropolitan area in an easily interpretable fashion, identifying areas with limited accessibility and establishing comparisons between mode choices. The tool seeks to contribute to better-informing transport policy and accessibility appraisals and identifying potential spatial inequalities in relation to transport in urban areas, which was tested in various forums with local decision-makers and non-specialists in Colombia.

Roads Development Optimization for All-Season Service Accessibility Improvement in Rural Nepal using a Novel Cost-Time Model and Evolutionary Algorithm

“…Speeds are assigned to segments of this network which are used to calculate travel times between origin-destination pairs, with adjustments for impedances like traffic or border crossings. Implementations of network analysis range from the study of Páez (2004) on network accessibility's relationship to economic activity in East Asia, the study of intra-city accessibility in Colombia by Sabogal et al (2018), World Bank studies of accessibility to jobs in Cox's Bazar Bangladesh (World Bank, 2020), and even Google Maps's Directions tool.…”