This article analyzes the relationship between transportation, land use and pollution in Latin American cities, and their consequences on urban quality of life. Economic growth and liberalization of national economies have lead to a strong growth in private motorization, yielding to growing congestion, which is the principal cause of urban degradation in our cities. A heavy concentration of cars in areas where high income population lives, together with an unorganized system of public transportation and lack of coordination between transportation and urban planning decisions, produce the inability to solve institutional and practical problems in the search of a higher quality of life. Heavy externalities are produced then, namely pollution, accidents, urban barriers and waste of energy. This article shows some examples and data on those phenomenons, introducing finally some successful experiences at world level, dealing with treatment and solving of this type of problems.