Evaluating the pedestrian accessibility to public services using open-source geospatial data and QGIS software

Abstract

This study brings a rapid method to utilize the available open-source geospatial data in assessing the pedestrian accessibility to key public services/facilities. At this stage, we are testing the method in the case of Tirana, the capital city of Albania. Yet, the method is reproducible to other metropolitan areas around the world. Open street map (OSM) data and reference layers from Albanian National authority for geospatial information (ASIG geoportal) have been used as the raw material of the study. While the geospatial visualization, refinement, and analysis rely on the usage of QGIS software and the related plugins. QNEAT is the plugin that was used to generate the isochrones which indicate the spatial coverage of a certain service referring to the existing urban transportation/circulation network. The plugin enables the definition of different distance ranges. Our results show that certain public services serve to various amounts of the building stock at a gradient of walking distances. For example, more than 25% of the existing building stock has pedestrian access to caffes and pharmacies within a walking distance of 250 m. The same services serve to almost 90% of the same building stock within 1 km walking distance. However, services like banks are accessible only by 12.6% of the existing buildings within a walking distance of 250 m, and 67% at 1 km walking distance. The accuracy of the available geospatial data resulted to be vital for the reliability of the results. We conclude by highlighting the importance and utility of GIS-based methods of urban analysis in the processes of planning new public services in the city.