Several recent guests on New Books in Political Science have talked about the path to political polarization in the US, including Lilliana Mason, Dan and Dave Hopkins, and Sam Rosenfeld. The deep divides between the parties have an obvious geographic dimension, but what is the cause? What has allowed people to sort themselves into cities, suburbs, and rural areas of the country? Clayton Nall has an answer to these questions: highways. Nall has written  The Road to Inequality: How the Federal Highway Program Polarized America and Undermine Cities (Cambridge University Press, 2018). In the book, Nall connects the federal programs to expand highway construction through the country to differences in political attitudes. In short, highways have contributed to sorting and polarization, allowing people to live and work much farther away than in the past. Using a variety of interesting sources of data, Nall also shows how this sorting has had different impacts on attitudes about transportation spending, with Republicans and Democrats holding distinct views on how federal money should support the physical connections between communities.  Learn more about your ad choices. Visit megaphone.fm/adchoicesSupport our show by becoming a premium member! https://newbooksnetwork.supportingcast.fm/geography