Mobility in the 15-Minute City

The project uses large scale urban mobility data sets derived by cell phone data to quantify to what extent US cities are conforming to the 15-min city vision, according to which primary services should be accessible within a 15min walking/biking radius. Besides accessibility, the project investigates to what extent local services are actually used by residents, and whether and to what extent localized mobility as promoted in the 15-min city concept might induce more social segregation within the city.

Team members include: Timur Abbiasov, Cate Heine, Edward Glaeser, Carlo Ratti, Sadegh Sabouri, Arianna Salazar Miranda, Paolo Santi

Image credit: Senseable City Lab, data via Safegraph

The 15-Minute City Quantified Using Mobility Data

Americans travel 7 to 9 miles on average for shopping and recreational activities, which is far longer than the 15-minute (walking) city advocated by ecologically-oriented urban planners. This paper provides a comprehensive analysis of local trip behavior in US cities using GPS data on individual trips from 40 million mobile devices. We define local usage as the share of trips made within 15-minutes walking distance from home, and find that the median US city resident makes only 12% of their daily trips within such a short distance. We find that differences in access to local services can explain eighty percent of the variation in 15-minute usage across metropolitan areas and 74 percent of the variation in usage within metropolitan areas. Differences in historic zoning permissiveness within New York suggest a causal link between access and usage, and that less restrictive zoning rules, such as permitting more mixed-use development, would lead to shorter travel times. Finally, we document a strong correlation between local usage and experienced segregation for poorer, but not richer, urbanites, which suggests that 15-minute cities may also exacerbate the social isolation of marginalized communities.

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Is the Tiny Little Neighborhood the City of the Future?

Why the hyper-local ‘15-minute city’ is gaining ground in urban planning circles, Henry Grabar for the Guardian.

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The Pushback Against the 15-Minute City

Carlo Ratti and Robert Muggah offer insights into the flaws and dangers of detractors of the 15-minute city in a Boston Globe opinion piece. 

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