In recent decades, urban processes have experienced deep transformations. One of them has been the growing importance of urban sprawl. This article reviews its main features and the policies related to the paradigm of sustainability in three Latin American Megalopolises: Mexico City, Lima, and Santiago de Chile. For this purpose, we have carried out an extensive
compilation of the existing academic literature. Urban sprawl in those cities cannot be understood without considering the rising housing needs of popular classes, usually addressed through the sequence settlement-parceling-building-urbanization. Simultaneously high-income groups tend to create separated and gated commodities and there is increasing spatial mobility of the middle classes. Those processes tend to generate highly segregated and increasingly patched metropolitan areas. Sustainability is framed on models of urban governance based on ecological modernization. In this context, three main sustainable policies are analyzed: water supply, green areas provision, and transport. Conclusions stress: (1) Deep changes experienced and the path-dependent element observed in the social construction of sustainability (2) Consolidation of a model of socially segregated and ecologically differentiated urban polycentrism (3) Relevance of the different megalopolises as niches of experimentation and innovation in the construction of specific forms of sustainable transition
