This study documents how residential segregation is visible in social interactions in the (semi) public space of the red line L‐train in Chicago. While public spaces are often celebrated as spaces of cosmopolitanism, people tend to interact mainly with people who look similar and appear to be living in the same area in Chicago. People of different race and class, represented by the station where they board the train, do not encounter each other much in the L‐train because of the existing residential segregation in the city of Chicago. Blacks ride from the south to downtown while whites ride from the north to downtown. Different time frames are reserved for different people. Furthermore, on the train itself people prefer to be interacting with and sit next to people who appear alike; who seem to be from the same part of the city. Hence, I argue that social interactions on the subway are mainly an expression of geographical and social exclusion in the city. Residential segregation is visible in the “segregation of social interactions” in the red line L‐train. Consequently, while de jure segregation has been abolished in the 1960s in Chicago, segregating practices are still going on de facto in everyday life.