https://phys.org/news/2018-07-nairobi-car-free-daysthey-benefits.html

All of these changes will need to be done quickly and efficiently. Given the lack of public transport infrastructure in the city, those who can't afford a private vehicle generally commute using buses or matatus (40.6%) – privately owned minibuses which will be phased out. And those who can't afford any form of transport generally walk (39.7%).

But the effort will be worth it. Research shows that cities benefit from car-free days in many ways. This includes traffic decongestion and reductions in time wasted, fewer car crashes and less noise and air pollution. Car free days also increase social interaction and physical activity. Overall the change will, if sustained, improve the health and well-being of the city's residents.