This chapter studies civil society’s engagement in social innovations that facilitate, promote or challenge the sharing of public spaces for bicycle use in cities. It illustrates civil society organisation's expanding role with innovative practices aimed at changing local environmental, social, cultural or economic unsustainable patterns and, impacting the field of environmental sustainability. Tracing the evolution of the stream of social innovation included selecting intermediate milestones during the period and mapping the contributions of key actors in advancing the innovation toward that milestone as reached within each respective city. The resulting analysis produced a thick story for each city. The chapter discusses the results, covering them in three parts: the city background, the dimensions of innovativeness and the evolution of social innovation. Copenhagen shows that a supportive culture is indispensable for reaching dimensions that have a lasting environmental impact, but it is less clear how the other cities could engage in creating a similar larger impact.