Nairobi's traffic problem had become legendary. A city of five million people served by road infrastructure designed for one million. In 2019, construction began on the Nairobi Expressway, a raised toll road running from Mlolongo on the outskirts of the city to Westlands, bypassing the central business district. When it opened in 2022, it genuinely worked. The journey that had taken two hours in traffic took twenty minutes. Kenyans who could afford the toll used it daily. Those who could not continued to sit in jams. Infrastructure had improved. The inequality it reflected had not.