Although the world population has historically been rural, there are now more people in urban areas than in the rural hinterlands for the first time in history. According to UN estimates, in 2010 more than 3.5 billion people (50.6%) will inhabit urban centers around the world, with the highest concentration of large urban centers in Asia (Table 1, Figure 1). Typical of this concentration is the metropolitan complex of Tokyo and Yokohama, Japan, with the largest urban population of approximately 36 million people (Figure 2). The growing urban areas need to provide for citizens’ demands for housing, employment, transportation, infrastructure, and the vast array of services and facilities. To meet these demands, it is essential to understand the environmental, social, economic, and political characteristics of ...