FIGURE 2.21 Photo Essay: Urbanization in North America North America is highly urbanized, with 79 percent of the population living in cities. Some of the wealthiest cities in the world are located here, though only a few have achieved high levels of “livability.” Many cities, especially those in the United States, are characterized by sprawling development patterns that require high levels of dependence on the automobile. 2.21a Courtesy Bob Martin/Sports Illustrated/Getty Images, 2.21b Courtesy Mario Tama/Getty Images, 2.21c Courtesy Carol M. Highsmith/Buyenlarge/Getty Images, 2.21d Courtesy Barry Williams/Getty Images