Informing design processes via agent-based modelling: A computational design strategy for enhancing precinct walkability

By Xiaoran Huang

Uncertainty and the complexity of urban environment raise doubts about static and solid decisions in the field of urban design.

Cities, like all other open systems, are complex and sometimes self-organizing. The context of a project, as a starting point of urban design, is constantly changing in a non-linear way (Portugali, 2000). However, urban design nowadays almost always presents a fixed blueprint based on a snapshot of a situation. This approach is not capable of fulfilling the necessities of the urban regeneration process. (Beirão et al., 2011) Therefore, the objective of urban design needs to move from a static design of a particular layout toward complex and speculative solutions.

The interest of this research is in developing a computational design strategy for different speculations by implementing a flexible and user-friendly ABM (agent-based modelling) application. The research is framed by Dunne and Raby’s 2013 proposal that speculative design can be categorised into three scenarios: probable, plausible and possible; where probable describes what is likely to happen; plausible open-ups what-if questions; and the possible makes links between today’s world and all possible futures, including all extreme conditions.

If we see pattern order and regularity, we should … inquiry first of all what it is that the individuals who comprise the system to be doing and how it is that their actions, in the large, produce the pattern we see.

Schelling, Thomas C.

This research will be actualised via an ABM design prototype that focuses on precinct walkability issues. This approach will be validated and tested using three case studies in Melbourne, Tianjin and San Francisco. Varying disturbances will be introduced while the degree of speculations will determine the scales of disturbance.

To achieve technical achievability and design flexibility concurrently, this study is undertaken through four primary empirical and non-empirical research tasks. The first includes an in-depth study of the computational strategies, complexity issues and emergence phenomena involved in urban design. The second is to understand how agent-based modelling can potentially engage with different design speculations: enhancing precinct walkability has been chosen as the objective in this research. The third task proposes a novel digital design prototype to analyse and visualise walkability and test emergent properties to suggest design decisions. Lastly, the prototype will be evaluated and optimised by being implemented in different case studies, testing how to apply ABM in the urban design process in terms of enhancing walkability.

The main contributions of this research are threefold: it develops and tests a computational design strategy that informs multiple design speculations; it creates and applies a flexible and user-friendly ABM prototype; and it contributes to the understanding of how ABM can engage with walkability issues.