Public perception on hostile landscape architecture in urban residual spaces under flyovers in Western Province, Sri Lanka

Abstract

Residual spaces are unintended byproducts of infrastructure-led urban development, often found beneath flyovers or along transportation corridors. They highlight fragmented city planning and a lack of inclusive spatial strategies. These areas are informal and unsafe neighbourhoods where marginalized groups often live in neglect and poor management. As a result, these spaces reflect urban inequalities by highlighting the problems of spatial exclusion and access to shared urban resources in an unequal manner. To address such challenges, many global cities have adopted hostile architectural urban design strategies aimed at deterring unwanted behaviour through physical barriers or discomfort. This study aimed to explore the relevance and appropriateness of such strategies in the Sri Lankan context by evaluating public perceptions of residual spaces beneath three flyovers: Kelaniya, Nugegoda, and Dehiwala. Using mixed methods, the study examined the role of design elements like form, texture, colour, accessibility, functions, and visual weight on how people feel and belong in the place. It employed site-based observations and questionnaire surveys, including a pre-test/post-test analysis to record any perceptual changes with regard to an altered spatial design. Findings suggested that the absence of thoughtful landscape interventions contributed to increased misuse of the public space and social disengagement. Based on public perception data, it is anticipated that the necessity of the strategic hostile landscape interventions at residual spaces is increasing, not to exclude but to frame their controlled usage. In this study, it is suggested that the design of neighbourhood character of residual spaces should be capable of controlling behaviour and also the accessibility of the population by integrating landscape architecture.