By Carey L. Biron
WASHINGTON - Mapping informal footpaths could help city planners tackle a range of urban issues stemming from depopulation and vacant land, researchers said on Wednesday.
At the beginning of the decade, the northern U.S. city of Detroit had more than 5,680 informal paths, many of them in lower-income neighbourhoods, according to a study by the University of Michigan and Illinois State University.
By 2016 those numbers had plummeted, with total footpath length falling by 70% in the Lower Eastside of Detroit, found the report - which combined satellite imagery and interviews - as the city fenced off and transferred vacant land to private developers and others.
For a city in which a quarter of residents have no vehicle and poor access to public transit, the effect is significant, said co-author Joshua Newell, an associate professor at the University of Michigan.
"The city might want to formalize this, to look at how residents have used these paths, to facilitate the flow of traffic and also to deal with safety challenges," he told the Thomson Reuters Foundation.
From Finland to the United States, cities are turning to informal footpaths — also known as "desire lines" — to inform a more organic, responsive form of planning and fight issues like urban decay.
Officials in Detroit, a post-industrial city that has lost 65% of its population since the 1950s, are seeking to redevelop vast swathes of vacant land, totalling 23 square miles (60 sq km), according to the report.
"The city has such large amounts of (vacant) land, and they're not going to be able to sell all of these lots, so they'll have to think creatively to rescale the city and use it in a different way," said Newell in a phone interview.
A city hall spokesman did not respond to a request for comment.
Other cities have followed suit, with Finnish officials looking to where people walk in parks after snow has covered official pathways to guide future planning, for instance, and several U.S. universities using similar strategies.
Paying attention to desire lines "helps with using space in ways that is not only efficient but useful," said Andrew Furman, an associate professor at Canada's Ryerson University, who has studied the issue.
Furman said the Detroit study is important because it "reinforces how invisible desire lines often are when viewing many different maps of an area".
Many cities in the United States, Europe, Japan and elsewhere are suffering from declining populations amid post-industrial economic transitions, Newell said, and should be thinking about auditing their own footpaths.
For any city "thinking about redevelopment and transferring land from city to private or other uses, this is a key component," he said.