1. Population clusters and transportation flows critical to the major industries on the continent. Indicate relative size and importance to South America such as the importance of the Interstate Highway System to the trucking industry in the United States or the Siberian Railroad to parts of Asia.
2. Relative location of population clusters over 1 million (i.e., SMSA, not city); ground, water, and air transportation networks between major population clusters (railroads, roads, major commercial airline routes), and major shipping routes (trucks, trains, planes, boats).