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Harry W.Richardson, Chang-Hee Christine Bae and Murtaza Hatim Baxamusa
Developing country cities in general have much higher congestion levels than
their developed country counterparts. This is, in part, a consequence of
densities, particularly in low-income countries where animals, market stalls on
the street and pedestrian overflows onto the road impede traffic. But it is also
the result of inadequate allocation of land to road space (Ingram and Liu,
1999), reflecting the fact that planning and design guidelines (to the extent
that they exist in developing countries) predated the introduction of the
automobile there. The situation has been exacerbated by the absence of traffic
management, and the absence, or very weak enforcement, of parking
regulations.
Environmental externalities
The great urban economist and demographer, William Alonso (whose untimely
death occurred in 1999), pointed out many years ago the fallacy of correlating
densities with environmental quality variables (Alonso, 1973). Of course,
traffic congestion tends to be worse in dense neighbourhoods, and because
damage to human health is the main component of many environmental costs
(e.g. of air pollution) total exposure (i.e. average exposure x the number of
people exposed) will be higher in high-density locations. But the quality of
the environment reflects many considerations that have nothing to do with
density. These include industrial structure, climate, topography, water sources,
institutions, regulations, the types of policy instruments and enforcement rates.
The correlation between SO 2 levels and densities is -0.18 (based on the data in
the master data set), hardly encouraging for those with faith in densification
strategies as a pollution control device. There may be a direct relationship
between the quality of water, sanitation facilities and solid waste management,
and the density of squatter settlements, but again other influences, such as the
presence or absence of slum upgrading programmes, may be much more
important than settlement density.
Hardoy and Satterthwaite (1992) have a different view. They argue that high
densities are an advantage: high population densities reduce the unit costs of
infrastructure and services with obvious environmental benefits in terms of
piped water, sanitation, garbage collection, drainage, etc.; high production
densities generate economies in waste-handling and facilitate regulation
enforcement. Even in squatter settlements, they argue that density is less
important than overcrowding (where cramped conditions can contribute to
transmission of infection and accident risks). However, they recognise that any
benefits from high population densities can be frittered away by the lack of
institutional capacities, e.g. to deliver services.
Sustainability and urbanisation
The sprea|d of the concept of sustainability, and its application in an urban
context, has been widely but not consistently discussed. Its urban aspects have
focused heavily on non-automobile dependence and on ecological footprint
discussions (e.g. the resource use associated with urban consumption levels),
with the presumption that developing country cities are more sustainable. If
this is the case, then the most convincing explanation would be the effects of
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