Public spaces design has for a long time been restricted to a primarily functional approach: travel and parking have been given preferential treatment to the detriment of local life and the urban environment. Grand Lyon has managed to introduce a policy and a way of organising its departments so that public spaces are better dealt with, through a more global approach to the public and to the characteristics of the various sites, and by exerting more influence in respect of the implementation of those policies. Thus, besides the information catalogued therein, the first part of this report is dedicated to bringing to the fore the working methods and strategies that have evolved for overseeing the development of a conurbation's public spaces. The case of the Cité Internationale is presented with reference to the way the project was set up and organised. The particularity of the project was the creation of a special monitoring and co-ordinating structure, the SEM de la Cité Internationale, its expansion potential over a 25-year period and the large number of actors present from both the public and private sectors during the design and development phases. This study is an opportunity to present an example of a method for the completion of complex projects.