Today's urban streets are usually planned for purposes of mobility: pedestrians, as well as a variety of vehicles such as cars, trucks, and sometimes bicycles, are usually factored into an urban street plan. However, urban streets are also increasingly recognized as public spaces, accommodating street vending, food trucks, markets, artistic interventions, political expressions, comfortable benches, green spaces. Although these are mostly not new activities to appear on streets, they are now given particular attention in public discourses, urban planning, media and academia, as public space in cities has become a more contested resource among different uses and ownership-constellations. Growing and diversifying urban populations are generating a particular strain on urban streets worldwide. In short, urban streets epitomize the challenges and opportunities that accompany the negotiations of space and uses attributed to mobility and public space in cities. They necessarily unite stationary and mobile functions – though this is not usually given room for in planning. Moreover, these functions are rarely studied from more than one perspective at once, which limits the analytical and creative thinking that inspiration is drawn from. In order to address these limitations, in this article we rely on insights from three theoretical fields - namely planning regulation, transitions and governance - and illustrations from concrete examples, to explore what urban planning might have to focus on to address the tensions in linking stationary and mobile functions in urban streets.