From urban clusters to megaregions: mapping Australia’s evolving urban regions Matthew Kok Ming Ng, Zahratu Shabrina, Somwrita Sarkar, Hoon Han, Christopher Pettit Computational Urban Science, 2024 This study employs percolation theory to investigate the hierarchical organisation of Australian urban centres through the connectivity of their road networks. The analysis demonstrates how discrete urban clusters have developed into integrated regional entities, delineating the pivotal distance thresholds that regulate these urban transitions. The study reveals the interconnections between disparate urban clusters, shaped by their functional differentiation and historical development. Furthermore, the study identifies a dichotomy of urban agglomeration forces and a persistent spatial disconnection between Australia’s wider urban landscape. This highlights the interplay between urban densification and peripheral growth. It suggests the need for new thinking on potential integrated governance structures that bridge urban development with broader social and economic policies across regional and national scales. Additionally, the study emphasises the growing importance of national coordination in Australian urban development planning to ensure regional consistency, equity, and productivity.
Incorporating diminishing returns to opportunities in access: Development of an open-source walkability index based on multi-activity accessibility Josephine Roper, Matthew Ng, Christopher Pettit Journal of Transport and Land Use, 2023 In this paper, we argue for an explicit decoupling of “walkability” and “walking behavior” and for the advantages of a definition of walkability based on access. This provides impetus for a new approach to constructing and using walkability indices, combining accessibility theory with a goal of comprehensiveness and communicability. Diminishing returns-to-opportunities can be used to map the infinite origin-destination gravity potential space to a finite scale thus creating an easily communicable metric, or metrics. In addition, this method can be applied to any mode and applied to multiple destination types singly or combined. Application of this theoretical approach is demonstrated through the creation of a novel comprehensive open-source transport walking potential index, WalkTHERE. A 0-100 scale is used to represent the percentage of people’s total needs potentially accessible by walking. The index is applied to eight Australian and two European cities, and the specific data considerations and parameters chosen are described. Significant disparity is shown in walking access between different destinations within cities, and in walking access between cities. Walking access to recreational opportunities is highest, followed by education and shopping, with very little employment access for most residents. Avenues for expansion and further validation are discussed.
COLOURING AUSTRALIA: A PARTICIPATORY OPEN DATA PLATFORM J. Roper, P. Hudson, H. Petersen, C. Pettit, T. Russell, et al. ISPRS Annals of the Photogrammetry Remote Sensing and Spatial Information Sciences, 2022 Colouring Australia is a digital platform for collecting and visualising building level information across several Australian cities. It provides a valuable resource for bringing together data on building age, material, sustainability ratings, walkability and other key metrics as we plan for net zero cities. Colouring Australia comprises part of the international Colouring Cities Research Programme, which supports the development of open-source platforms that provide open data on national building stocks. In this paper we outline the technical architecture of the platform, and the development and visualisation of a building level walkability metric based on pedestrian access to destinations. This platform provides a useful digital tool for planners to understand which parts of the city are walkable and in turn this can support future active transport programs and policies. Future research will be to validate this novel walkability index through a series of stakeholder and public workshops using the Colouring Australia platform in an interactive tabletop environment where usability testing can be undertaken.
