The book discusses some of the issues related to proximity, challenges an acritical use of the concept and highlights several dimensions that may better frame the actual contribution of proximity to urban and mobility planning in different places.The contributions address the conditions required for ensuring accessibility by proximity and the different planning dimensions that can support its promotion, addressing issues related to the inclusiveness of this model, as well as the scalability and metrics of proximity we need to deal with in several different contexts.The first part of the book introduces some experimental approaches aimed at operationalising accessibility by proximity, while the second part discusses several planning issues related to the implementation of proximity at different scales.