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
Transportation in North America Transportation in North America Transportation in North America is about a varied transportation system, whose quality ranges from being on par with a high-quality European motorway to an unpaved gravelled back road that can extend hundreds of miles. There is also an extensive transcontinental freight rail network, but passenger railway ridership is lower than in Europe and Asia. The railroad network of North America (using standard gauge) is extremely extensive, connecting nearly every major and most minor cities. The United States, Canada, and Mexico have an interconnected system with railheads stretching from Hay River, Northwest Territories, Canada to Tapachula, Mexico,