Some of the most pressing issues are so ubiquitous that they become invisible. But often, it is exactly these issues that are fundamental to our way of life. Take transportation: It is far more than a means of getting from A to B. Transportation is a gateway to opportunity and a reflection of a country’s class and gender relations, economic stability, political history and culture. It’s also arguably a basic right.

This series explores its role in three cities of the global south: Bogotá, Colombia; São Paulo, Brazil; and Nairobi, Kenya. In each city, transportation takes on a unique form. From Bogotá’s innovative use of the BRT (bus rapid transit) system, which has since become a model for countries around the world, to Nairobi’s informal and often dangerous Matatu mini bus system, to a highway in São Paulo that becomes a unique public space each week.