A San Francisco Chronicle article highlighted research findings by Urban Planning Associate Professor Adam Millard-Ball on the width of streets in San Francisco. In places with housing shortages, wide streets take up valuable land that could have been used to build more homes or other buildings, Millard-Ball said. While the average street in San Francisco is 50 feet wide, Millard-Ball proposed 16 feet as the functional minimum width for residential streets. In some areas of the city, streets are an average of 93 feet wide. Millard-Ball argued that in high-cost California counties like Santa Clara and San Francisco, the consequences of unnecessarily wide streets are enough to make the costs to narrow them worth it. For cities that are still growing, Millard-Ball suggested that planners build narrower streets to save land for housing. In established cities where narrowing the streets is not feasible, he proposed adapting unused street spaces into outdoor dining spaces, slow streets and other recreational spaces.