It is common sense in the urban mobility, literature to address the positive aspects of mobility infrastructures because of their ability to connect urban spaces. In order to promote a critical debate about these elements, the dissertation aims to point out the dimension of segregation on mobility infrastructures, exploring two aspects: that of socio-spatial segregation, on a city and metropolis scale, addressing the center-periphery dichotomy, and the segregation of the urban form, on a neighborhood scale, either by the presence of scattered and fragmented urban fabrics, as well as by new and different scales of buildings built around the mobility infrastructures. Then, the research is based on the object of Avenida Brasil, an important expressway built in the 1940s, which crosses the city of Rio de Janeiro from one end to the other, serving as one of the structuring axes in the occupation of the west zone. In its extension, there are several modes of occupations, related to different dimensions of segregation. A comparative analysis, based on three distinct occupational patterns of low-income housing and its surroundings, is ultimately intended of to measure the impacts of segregation on stretches.