In places like Dar es Salaam, far more children are killed by the drivers of cars, trucks and motorcycles than are killed by Aids, malaria or diarrheal diseases.
A growing movement is taking aim at motor vehicles in the quest to solve traffic congestion, slash carbon emissions and create more-livable cities.
One of Europe's most car-dependent capital cities is speeding up its timeline for change.
Rome and Paris saw the biggest drops in pedestrian activity. London, LA and Sydney saw the least.