Everybody in town! Should periurban scattered settlement be prevented in order to decarbonize mobility?[¡Todos en la ciudad ! ¿Deben evitarse los asentamientos periurbanos para descarbonizar la movilidad ?]

This paper examines the effects on CO2 emissions from daily mobility of various scenarios of periurban residential location. These scenarios are studied on two contrasted periurban areas, one depending on the urban agglomeration of Lyon, the other on the urban agglomeration of Strasbourg. The study is focused on the polarization of urbanization, based on the hypothesis that, with regards to urban planning, the issue is less linked to the densification of the urban fabric than to its polarization. However, the relocation of housing in selected periurban poles results in limited reductions of CO2 emissions. The social and political costs of these scenarios and their low impact on CO2 emissions make their relevance even lower, especially when compared to mobility scenarios. Finally, the role of urban planning for easing these mobility scenarios is discussed.