  Despite modest declines in residential segregation levels since the Civil
Rights Era, segregation remains a defining feature of the U.S. landscape. This
study highlights the importance of considering physical barriers--features of
the urban environment that disconnect locations--when measuring segregation. We
use population and geographic data for 20 U.S. Rustbelt cities from the 2010
decennial census and a novel approach for measuring and analyzing segregation
that incorporates the connectivity of roads and the excess distance imposed by
physical barriers, such as highways, railroad tracks, and dead-end streets. We
find that physical barriers divide urban space in ways that reinforce or
exacerbate segregation, but there is substantial variation in the extent to
which they increase segregation both within and across these cities and for
different ethnoracial groups. By uncovering a new source of variation in the
segregation experienced by city residents, the findings have implications for
understanding the mechanisms that contribute to the persistence of segregation
and the consequences of segregation.
