GIS-based transport accessibility analysis to community facilities in mid-sized cities

Transport accessibility is an important issue for the sustainable development of cities. This work presents a GIS-based accessibility analysis approach that can be applied to assess accessibility to community facilities in medium-sized cities using publicly available data. For that purpose, a case study was developed using the road network and public transport data from Covilha municipality, in Portugal. Data collected on websites were treated and organized to build the network dataset and perform network analyses with the aid of the ArcGis (R) Network Analyst extension (creation of service areas and Origin-Destiny (OD) cost matrices). Four accessibility evaluation analyses were performed for two transport modes: accessibility to the municipality main community facilities by private and urban public transport (isochronous and OD matrices), by inter-urban public transport (time); and accessibility by private transport between civil parishes (isochronous and OD matrices). The population and the territory covered by different travel times were also determined. The case study results showed that the accessibility in Covilha is quite reasonable, either using private transport inside the municipality (maximum 30 minutes for covering nearly 95% of the resident population and 83% of the territory), or urban public transport inside the urban perimeter (maximum 50 minutes). However, the periphery civil parishes of the municipality have lower levels of accessibility for inter-urban public transport (reaching 115 minutes). The utility of the approach was validated through the results obtained in the case study, where it was possible to observe patterns of accessibility across the municipality for the considered modes, making it possible to improve the overall accessibility through the identification of priority areas of intervention.