Lacking a strong public transit system, residents of Nairobi, Kenya, often get around the city using “matatus” — group taxis following familiar routes. This informal method of transportation is essential to people’s lives: About 3.5 million people in Nairobi regularly use matatus. Some years ago, around 2012, Sarah Williams became interested in mapping Nairobi’s matatus. Now an associate professor in MIT’s Department of Urban Studies and Planning (DUSP), she helped develop an app that collected data from the vehicles as they circulated around Nairobi, then collaborated with matatu owners and…
