Pedestrian safety remains a marginalised aspect of road safety research and policy, despite its relevance to sustainable cities, public health, and social equity. This thesis investigates how pedestrian safety is shaped by the wider road safety system, one that extends beyond national boundaries and is influenced by international policy frameworks, funding mechanisms, and shared strategies. Global initiatives such as Vision Zero and the Safe System approach, adopted by the United Nations and national governments including the UK, prioritise reductions in killed or seriously injured (KSI) casualty statistics. These metrics support data collection, funding allocation, and safety intervention design across all levels of the system. This KSI-focused framing narrows the definition of safety, excluding near-misses, non-collision injuries, and the daily risks encountered by pedestrians, particularly those with protected characteristics. Through qualitative research comprising interviews, surveys, and participant observation with pedestrian groups in London, this study explores how road safety experts conceptualise safety and how those framings contrast with the lived experiences of pedestrians. Drawing on Constructivist Grounded Theory, Affordance Theory, and Research through Design, it exposes how systemic practices privilege numerical indicators of success while neglecting contextual and embodied knowledge. The findings reveal a consistent disconnection between institutional definitions of safety and the complexities of real-world pedestrian experience. A key contribution of this research is the development of GroundMap, an Affordance-Disaffordance diagnostic tool that makes visible what standard safety audits cannot capture: the removal of safety features, the creation of new risks, and the consequences of design decisions for diverse pedestrian groups. Applied across three phases of design practice in London, GroundMap produced evidence that transport authorities acknowledged as distinct from their routine datasets, resulting in commitments to revise existing designs. By situating pedestrian safety within a transnational system of targets, norms, and practices, the thesis calls for a broader, design-led reframing, one that engages directly with users and incorporates the diverse needs of those using public space. This work contributes to academic discourse in design, mobility, and policy studies by illustrating how international governance structures influence local safety outcomes, and how inclusive design methods can address persistent gaps in current approaches. Keywords: pedestrian safety, Affordance Theory, disaffordance, GroundMap, wicked problems, inclusive design, Vision Zero

Funding: LAHP [2086662]