Exploring sustainable urban mobility through the lens of theory of planned behaviour

Abstract

Urban areas worldwide face significant challenges in achieving sustainability, particularly within the urban transportation sector, which profoundly impacts economic, environmental, social, and mental well-being. In Sri Lanka, these challenges are exacerbated by unsustainable urban planning practices and mobility policies that inadequately reflect the context-specific factors influencing urban mobility behaviours. Therefore, the concept of sustainable urban mobility is critical for addressing these multifaceted issues, as it is fundamentally grounded in human-centred, economically viable, and environmentally responsible approaches. When implementing the most effective sustainable urban mobility approaches, active mobility and public transport often encounter challenges arising from numerous influencing factors. In this context, the study extends the Theory of Planned Behaviour (TPB) as a framework to systematically explore and deepen the understanding of these factors shaping urban mobility practices. Accordingly, through a mixed-method approach involving a literature review and focus group interview, six key variable categories were identified as influencing commuters’ transport mode choice. A single case study, centred on a documentary review, observations, and a questionnaire survey, was conducted to investigate the most influential variables within these categories, along with their magnitude of influence and the nature of their interrelationships in the Sri Lankan context. Subsequently, expert interviews were carried out to develop thirty strategic themes directly addressing the TPB variables that shape transport mode decisions. The resulting strategies emphasise that, beyond physical infrastructure development, context-specific interventions including age- and gender-responsive policies as well as strategies sensitive to environmental, social, and cultural values, are essential for the optimal performance of sustainable urban mobility. Ultimately, this study proposes a new paradigm in urban transport planning, arguing that sustainable urban mobility is not merely about planning for people, but people for planning, through the deep integration of environmental, social, cultural, and economic realities.