What matters when it comes to “Walk and the city”? Defining a weighted GIS-based walkability index

Promotion of daily walking activity is the focal point of urban mobility in many cities, since it tackles issues that stem from the proliferation of auto-dependent lifestyles. The idea of walkability can be defined as the extent to which the built environment supports and encourages safe, comfortable and interesting urban walking trips. Thus, walkability is a relative composite measure, which can be geovisualized by assessing both built environment characteristics that affect people's travel behavior as well as information gathered through audits and surveys. To this end, our paper deals with the definition of a weighted GIS-based composite walkability index methodology. During the first phase the following parameters formulate the initial value of our index: population density, pathway network connectivity, land use mix and proximity to basic land uses. In the second phase, pathway characteristics such as its width, obstacles and condition, with problematic values negatively affect the index and reduce its value. Although the international debate in this scientific field has not yet concluded whether a walkability index should be weighted or not, we delve into the exploitation of the suitable index's parameters weights. In our study, weights ensued from a Pan-Hellenic electronic questionnaire survey constituting of a sample of 871 people mainly sought the hierarchical significance of each of the walkability index's parameters and sub-parameters according to the preferences of respondents which stated they basically choose walking/cycling to their daily destinations. Hierarchy analysis of results was carried out through the utilization of the Borda count election method, a consensus-based method instead of a majoritarian one. Results indicated that proximity to basic urban destinations is assigned the highest weight with a value of 38.3% and population density the lowest with a value of 13.8%. Finally, pathways with small or zero width reduced the index's initial value up to 41,1%.