A recent study shows that for every significant freeway that gets built in a major city, population declines by about 18%. Nathaniel Baum-Snow, author of the study, talks with Planetizen.
Nathaniel Baum-Snow is a professor of economics at Brown University. His research has been remarkable consistent and urban-centric since writing his dissertation in 2000 on "The Effects of New Public Projects to Expand Urban Rail Transit." Baum-Snow’s work came to our attention when he was cited in a recent Boston Globe article quoting his study that concluded that each new federally-funded highway passing through a central city "reduces its population by about 18 percent." The implication of this type of data-driven evidence of the effect of highway construction on cities is often hard to find, so we went to the source.
You can read the interview here: http://www.planetizen.com/node/43413 [1]