Source: United Nations, Department of Economic and Social Affairs, Population Division (2006). World Urbanization Prospects: The 2005 Revision. New York: United Nations.
World Urban Population, 1950-2010 with Projections to 2030 (in billions)
Between 1950 and 2005 the global urban population has more than tripled to reach 3.15 billion. While urbanization has considerably slowed down in more developed countries, the developing world is where cities are growing the most. It accounted for 68% of the urban population in 2000 and by 2020, 77% of the global urban population is expected to be in less developed countries. This process will be accompanied with significant surges in urban mobility demands. On the other hand, because of density advantages, mobility demands in urban areas can be more efficiently accomodated by collective transportation than mobility demands in rural areas.