With the rise of chronic diseases as the number one cause of death and disability among urban populations, it has become increasingly important to design for healthy environments. There is, however, a lack of interdisciplinary approaches and solutions to improve health and well-being through urban planning and design. This case study offers an HCI solution and approach to design for healthy urban structures and dynamics in existing neighborhoods. We discuss the design process and design of ROOT, an interactive lighting system that aims to stimulate walking and running through supportive, collaborative and social interaction.