SFI External Professor Luis Bettencourt and Nicholas Marchio from the University of Chicago have developed a new approach to mapping infrastructure needs across sub-Saharan Africa. Their research uses data on more than 415 million buildings in 50 countries, offering detailed insights into urban development at the street block level.
The study, published in Nature, introduces the concept of "block complexity," which measures how challenging it is to provide street access to every building within a neighborhood. The researchers found that areas with higher block complexity are often missing key services such as piped water, legal addresses, and emergency access—conditions common in informal settlements. According to their estimates, over half a billion people in sub-Saharan Africa live in these high-complexity zones, including both rural communities and regions on the edge of cities.
“This paper shows how we can measure and then begin to address those deficits for each household in every building, anywhere in the world,” Bettencourt says.
This research builds on a long-term project begun at the Santa Fe Institute aimed at creating predictive models for urban networks. The findings provide tools for local governments, NGOs, and development agencies to better identify where infrastructure improvements are needed most and to plan targeted solutions at the neighborhood scale.
The full paper is available in Nature under the title “Infrastructure deficits and informal settlements in sub-Saharan Africa” (September 03, 2025) at DOI: 10.1038/s41586-025-09465-2
