Urban design interventions reduce fear of crime in public spaces in gender-sensitive ways

Fear of crime in public spaces is a major policy problem worldwide. Environmental Crime Prevention (ECP) proposes that modifying the built environment can reduce fear of crime, but key questions remain: are these interventions equally effective across genders, and what intensity maximises safety perceptions while optimising costs? We evaluated three interventions: 'Eyes on the Street' (adding windows to blind walls), neutral stimuli (removing graffiti by repainting walls), and 'Nature-Based Solutions' (integrating tidy vegetation into urban infrastructure) in the context of ‘Broken Windows’ disorder. Interventions were applied at varying intensities across four types of public spaces. Using a randomised experiment in Chile with photo simulations and an adapted Positive and Negative Affective Schedule, we collected 18,150 perception ratings from 2,028 respondents. Results show that safety improvements are positive but non-linear, indicating diminishing returns beyond a certain intervention intensity. Critically, responses were highly gender-specific: interventions were more effective for males, suggesting that environmental changes alone do not fully address women's perceived insecurity.