Source: Urban population data from United Nations, World
Urbanization Prospects: The 2007 Revision Population Database.
Kenworthy J, and F. Laube (2001) The Millennium Cities Database for
Sustainable Transport, International Union of Public Transport
(UITP), Brussels and Institute for Sustainability and Technology
Policy (ISTP), Perth.
Sustainable Urban Passenger Travel, Selected Cities
The above map provides a typology of the sustainability level of
urban passenger transportation systems from a sample of 64 cities
across the world. The classification is mainly based on the
assumption that a high level of reliance on the automobile coupled
with low density levels is less sustainable than lower levels of
automobile dependency and higher densities. Five major classes can be identified:
The typology has a distinct geography. North American and
Australian cities are dominantly in class E with a few of the denser
cities (e.g. New York, Toronto) in class D. This is mostly related
to automobile dependency. European cities rank higher on the
sustainable passenger transportation scale, mainly due to the higher
role of public transit and denser urban settings. This
characteristic is also shared with many Latin American cities. East
Asian cities are generally on top of the urban passenger
sustainability scale. However, rapid development and motorization in
the majority of large Chinese cities (e.g. Beijing and Shanghai)
has resulted in a relative decline of their sustainability
level. Southeast Asia cities having a high level of automobile dependence, such
as Bangkok and Saigon, are is a similar situation.
Efficient and productive cities are not necessarily linked with
high levels of energy consumption
per capita. The first three classes of
cities (A, B and C) are characterized by high densities and rely on public
transit for mobility, while the last two classes (D and E) have
lower densities and rely on the automobile for most urban movements.
A shortcoming of the above classification is that it considers only
one dimension of urban transportation; the mobility of passengers.
Cities are also subject to intense flows of goods since they are
locations of production, consumption and distribution. Freight
distribution should thus be considered an important component of
- Class A. Comparatively most sustainable
transport. Very low automobile dependency, with public transport, walking
and cycling more prominent than cars, which involves very low gasoline use
- Class B. Comparatively more sustainable
transport. Low automobile dependency, public transport, walking and
cycling equal with cars, low gasoline use.
- Class C. Comparatively sustainable
transport. Moderate automobile dependency, important role for public
transport walking and cycling, moderate gasoline use.
- Class D. Comparatively less sustainable
transport. High automobile dependency, minor role
for public transport (important support for peak hour movements), walking and cycling, high gasoline use.
- Class E. Urban passenger transport systems
that are comparatively the least sustainable. They involve a very high
level of automobile dependency, a very limited role for public
transit, walking and cycling, as well as very high gasoline use.