In the next 20 years, African cities will more than double in population, and their spatial extent could more than triple. What form will this growth take? The current planning regime in African cities focuses on Comprehensive Master Planning, a slow and costly methodology. Many of these plans are never built, but the cities continue to grow rapidly in the absence of a framework. Recent evidence from the NYU Stern Urbanization Project indicates that this growth is highly informal and poorly laid out, lacking a network of arterial roads, for example. Over time, this will negatively impact productivity and the efficiency of the metropolitan labor markets in these cities – cities that are expected to drive GDP growth across the continent. As an alternative, NYU Stern Urbanization Project has developed a methodology entitled “Making Room for Urban Expansion,” which proposes to secure the bare-minimum public goods necessary for orderly growth – a network of arterial roads, and a hierarchy of public open space. In partnership with the Government of Ethiopia, NYU has tested this methodology in eighteen Ethiopian cities. This Ethiopia Urban Expansion Initiative has resulted in the designation and protection of hundreds of kilometers of arterial roads and large reserves of public open space. Beyond paper plans, the Ethiopia Urban Expansion Initiative has led to real changes on the ground, from the construction of many kilometers of road to a dramatic increase in the supply of land on the market in these cities. The conclusion is clear – a viable new method has been developed for addressing the rapid growth of Africa’s cities.