20 JUL 2026 (MON) 14:35 - 15:05

Contemporary Urban Accessibility Frontiers: from Planar to Volumetric, from Human to More-than-Human, and from Single to Multi-purpose Accessibility

Mr. NG Ka Yiu Benjamin    

( Supervisor: Prof Peter K Koh )

Abstract:

Urban accessibility is central to equitable, sustainable, and liveable cities. However, dominant frameworks remain misaligned with the volumetric, relational, and multispecies realities of contemporary urban life. This PhD research critically reframes accessibility through three interconnected transitions: from planar (2D) to volumetric (3D), from human to more-than-human, and from single-purpose to multi-purpose accessibility. 

From Planar to Volumetric: First, the study addresses limitations of traditional 2D and 2.5D network models that overlook complex multi-layered urban connections. It proposes the development of an open-source 3D geospatial package in R and QGIS tailored for 3D geometric operations and accessibility measurements. Complementing this, the research advances an ontology of errors associated with 2D, 2.5D, and 3D models, enabling more realistic and accurate accessibility assessments. 

From Human to More-than-Human: Second, the thesis integrates insights from New Animal Geography and Transport Geography to examine how more-than-human actors, particularly pets, shape the accessibility of people. Focusing on Hong Kong’s ongoing debates about pet-friendly public transportation, this thesis will examine the complexity of public perception regarding pet-friendly public transportation and how it intertwines with the agency of companion animals. Additionally, this thesis incorporates advanced 3D accessibility analyses to simulate the social and environmental implications of various pet-friendly transportation scenarios. 

From Single to Multi-purpose: Third, the study challenges single-purpose accessibility metrics by embracing the trip-chaining nature of everyday mobility. It compares aggregated single-purpose indices with novel multi-purpose accessibility measures to better evaluate 15-minute city concepts. Applying this framework, the thesis will assess Hong Kong’s accessibility landscape and critically appraise its status as a 15-minute city. A cross-regional comparison will further illuminate how multi-purpose metrics can unravel a different perspective of 15-minute city measurements. 

By integrating volumetric modelling, multispecies perspectives, and multi-purpose analysis, this research advances theoretically rich and methodologically innovative tools for urban planning. It aims to support evidence-based policy and foster more inclusive, sustainable cities that recognise the complex realities of urban life.