Walking to get to and from local destinations including shops, services, and transit stops is a major source of adults' health-related physical activity. Research has been using space syntax measures in examining how urban form is related to such routine walking for transport. This paper proposes to apply a theory of space syntax, natural movement, which posits street layout as a primary factor influencing pedestrian movement. Discussing how this theory can link urban form (street layout) and function (land use) with walking for transport, we propose a research agenda to produce new insights and advance methods in active living research.