Ensuring access to safe and affordable recreational spaces is vital for promoting well-being, especially in underserved communities facing barriers to physical activity. Shared use agreements, where school facilities are open for public use, offer a promising solution; yet limited research has examined how to maximize usage of these spaces. Framed under Social Cognitive Theory in a socioecological model, this dissertation comprises three studies contributing to this knowledge base to foster active, healthy communities. The first study was a scoping review of usage and physical activity behavior in school shared use spaces, highlighting the potential of shared use agreements to promote physical activity, especially when they included organized activities or space renovations. The study underscores the need for robust evaluations, gender- and population-sensitive interventions, and community engagement to maximize impact. The second study, adopting a pre/post, cross-sectional approach, assessed the impact of a multicomponent intervention on perceptions and usage of a school shared use path in South Phoenix (AZ). No statistically significant changes in usage were observed over time; however, access was a significant predictor of usage. Gender (female, negative) and safety perceptions (positive) were also identified as salient predictors of usage. The findings highlight the critical role of awareness (i.e., perceived access) in enhancing usage of school shared use spaces. The third study was a longitudinal natural experiment, with observational assessments of usage and related physical activity on one school shared use path over 12 months at an elementary school in South Phoenix (AZ). Moderate increases in usage over time were attributed to promotional efforts, social programming, and environmental modifications. Most users (>70%) of the path were observed walking, and were male, Hispanic, and adult. The study suggests that demographic disparities may exist. Implementing broader engagement strategies and understanding safety perceptions may facilitate more representative usage. Collectively, this dissertation provides a comprehensive evaluation of the potential of school shared use spaces to promote physical activity, while underscoring the importance of understanding complex factors influencing the usage of these spaces. Ultimately, the findings contribute knowledge to enhancing the usage of school shared use spaces, adding to the literature on their significance in promoting physical activity and community health, particularly in underserved regions.