CONTEXT: Recent efforts to increase physical activity through changes to the built environment have led to strategies and programs that use existing public space, including bicycle lanes, temporary parks, and the ciclovia initiative (scheduled events in which streets are closed to motorized vehicles and opened for recreational activities) popularized in South America. OBJECTIVE: This article describes and compares the processes and structures involved in developing and implementing a ciclovia-type program in 2 US urban contexts: San Francisco, California, and St Louis, Missouri. Considering the current growth of and interest in ciclovia initiatives, important outcomes, lessons learned are offered for application in other, similar settings. DESIGN: Primary sources from both initiatives and from published research on ciclovias constitute the body of evidence and include year-end reports, grant applications, meeting minutes, budgets, published ciclovia guidelines, evaluation studies and Web sites, media sources, and interviews and personal communication with the organizers. MAIN OUTCOME MEASURES: Primary source documents were reviewed and included in this analysis if they offered information on 3 grounded questions: What processes were used in developing the initiative? What are the current structures and practices used in implementation of initiatives? What are important lessons learned and best practices from initiatives for recommendations to stakeholders and policy makers in other contexts? RESULTS: Among the categories compared, the structures and processes for implementation regarding buy-in and city department collaboration, route selection, programming, partnerships, media promotion, community outreach, and merchant support were relatively similar among the 2 initiatives. The categories that differed included staffing and volunteer engagement and funding. CONCLUSION: Buy-in from community partners, merchants, residents, and city agencies is critical for a positive experience in developing and implementing ciclovia-type initiatives in urban environments. When funding and staffing are inconsistent or limited, the quality and sustainability of the initiative is less certain.