As more Americans move to cities at a staggering rate, one study has found that the decades-old trend of growing urban sprawl is beginning to reverse.
The new study, titled “A century of sprawl in the United States,” was published in Proceedings of the National Academy of Sciences of the United States of America.
Written by McGill University assistant professor Christopher Barrington-Leigh and University of California, Santa Cruz assistant professor Adam Millard-Ball, the study is “the first long-run, high-resolution time series of street-network sprawl in the United States.”
The study investigated urban development patterns in the US, mostly typified by urban sprawl, over the last 100 years. Barrington-Leigh and Millard-Ball measured sprawl through street network connectivity in the United States from 1920 to 2012 and discovered that sprawl was becoming the norm even before car ownership was widespread.
But from 1994 to 2012, sprawl fell by approximately 9 percent.
“Places that were built with a low-connectivity street network tend to stay that way, even as the network expands,” wrote Barrington-Leigh and Millard-Ball.
“We also find suggestive evidence that local government policies impact sprawl, as the largest increases in connectivity have occurred in places with policies to promote gridded streets and similar New Urbanist design principles.”
The authors explain that “new developments have already turned the corner toward less sprawl.” They see modest numbers regarding vehicle travel and greenhouse gas emissions but expect benefits to compound in future years.
These benefits include reducing climate change and energy and material waste, as well as mitigating public health challenges.