Cumulative (and self-reinforcing) spatial inequalities: Interactions between accessibility and segregation in four Brazilian metropolises

The inequalities that mark global society have been deepening worldwide. They materialize in cities, putting pressure on public transport systems for spatial and temporal supply, at the same time as mobility itself generates multifaceted inequalities. From empirical evidence of four socially and spatially distinct Brazilian cities — São Paulo, Rio de Janeiro, Curitiba, and Fortaleza — we explore how differences in scale, geography, class, and race are related to spatial segregation, leading to different levels of access to jobs by public transport in the global peripheral context. These juxtaposed and combined inequalities create highly unfair and strongly cumulative effects on some social groups, contributing to the reproduction of inequality. Based on public and open data and combining methodologies of spatial analysis to enhance comparability and reproducibility, we explore different areal units, time thresholds, and metrics in order to examine transport inequalities in different urban contexts and refine our results. Upper classes have higher accessibility than lower classes, whites have higher accessibility than blacks, and large cities are more unequal than smaller ones. However, racial inequalities combine and overlap with class and city inequalities, changing these dichotomic notions when multiple dimensions are considered. The groups that polarize social hierarchy also polarize the urban space, since the white upper class and the black lower class are more segregated, but the way segregation interacts with accessibility is not straightforward and varies according to the socio-spatial structure.