North America metropolitan area by population in North America: Greater Mexico City. Canada also breaks into the top ten largest metropolitan areas with the Toronto metropolitan area having six million people. The proximity of cities to each other on the Canada–United States border and Mexico–United States border has led to the rise of international metropolitan areas. These urban agglomerations are observed at their largest and most productive in Detroit–Windsor and San Diego–Tijuana and experience large commercial, economic, and cultural activity. The metropolitan areas are responsible for millions of dollars of trade dependent on international freight. In Detroit-Windsor the Border Transportation Partnership study
North America receives immigrants from all over Latin America and parts of Europe and Asia. Yet as cities grow in these warmer regions of North America, they are increasingly forced to deal with the major issue of water shortages. Eight of the top ten metropolitan areas are located in the United States. These metropolitan areas all have a population of above 5.5 million and include the New York City metropolitan area, Los Angeles metropolitan area, Chicago metropolitan area, and the Dallas–Fort Worth metroplex. Whilst the majority of the largest metropolitan areas are within the United States, Mexico is host to the largest