Multiple accessibility analyses of neighborhoods in Sydney

Climate change, hybrid working, and the pandemic have triggered significant changes in cities, including inner-city shrinkage and shifts in transportation modes and lifestyles. These changes have sparked interest in developing decarbonisation strategies to sustain socially and economically vibrant, inclusive cities that promote health and well-being through active mobility. Modifications to street network infrastructure have been a prominent focus of investment in this context, as it has now been demonstrated that street network design has a considerable influence on people's mobility behaviour in cities. Changes to street networks, such as prohibiting through-traffic and applying traffic calming strategies, can reduce car usage while also encouraging active travel, particularly over short distances. Increased active travel has significant environmental (i.e., enhanced air quality, reduced carbon emissions) and public health (i.e., enhanced physical and mental wellbeing) benefits.

This study, which is part of an ongoing larger research project, showcases a novel and technically advanced methodology to objectively evaluate the existing urban street networks in terms of their walkability and accessibility potential. Focusing on two SA2s (Statistical Area Level 2), which are medium-sized general-purpose areas, in Sydney, Australia, we employed refined GIS-based measures of accessibility using Place Syntax Tool (PST). PST is an open-access software that combines the space syntax description of the urban environment with traditional descriptions of the attraction. We conducted multiple accessibility analyses: (i) Syntactic centrality measures, including integration and choice, that can differentiate between well- and less well-connected streets within a given area; (ii) Attraction Distance, which measures network-based proximity to key amenities; and (iii) Attraction Reach to Population that calculates the number of people served by each amenity within a predetermined distance threshold. Through these analyses, we identified areas with a high residential population density but limited accessibility, and vice versa, and we identified spatial inequalities in how well key services (i.e., public transportation systems, and food outlets) serve the local population. These analyses offer a valuable tool with which to inform design interventions in the street network design, such as pedestrianisation of specific streets, improving the connectivity of access routes, including creating cycle corridors between the peripheral and central parts of the city, as well as improving access to key urban functions.