Anew study confirms what urban residents and advocates have known for decades: that America’s urban highways are barriers to social connection. The research, published this month in the journal PNAS, quantifies for the first time how highways have disrupted neighborhoods across the 50 biggest U.S. cities. Every single city studied showed less social connectivity between neighborhoods where highways are present.
“Nobody could put a number on the disruption, and now we can give a score to every single highway segment,” says Luca Aiello, a professor at the IT University of Copenhagen and the study’s lead author.
By comparing the social connections between people living on either side of highways to a baseline model of the same city with no highways, researchers found that the three U.S. cities that have experienced the most social disruption from highway infrastructure are Cleveland, Orlando and Milwaukee.
To infer individual social ties, the study relied upon geolocated user data from social media platform X (formerly Twitter). Researchers assumed that two individuals were connected if they had mutual followers and estimated users’ home location based on where their posts were sent from.