A recent study, published in the Proceedings of the National Academy of Sciences (PNAS), examines the unintended social consequences of urban highways. While these roads were originally designed to improve mobility, the study, conducted with contributions from the Complexity Science Hub, the IT University of Copenhagen, and Sándor Juhász from Corvinus University of Budapest and ANETI Lab, demonstrates that highways act as barriers to social relationships. By examining the spatial social networks of individuals within the 50 largest U.S. cities, the researchers found that highways significantly hinder connections, especially for those living less than 5 km apart. However, at distances greater than 20 km, highways start to help connect areas within the city.
The study utilized a novel approach, combining geographical data with location data from X (formerly Twitter) to map social connections and quantify the "barrier effect" of highways. The findings are particularly striking in cities with high segregation, such as Cleveland, where highways were often built through or between homogeneous neighborhoods, physically separating communities. The study’s findings also raise concerns over the long-term consequences of such infrastructure on social cohesion and inequality.