Modelling for sustainable cities: Conceptual approach and an audit of existing sectoral models for transport, air pollution, land use, and population modelling.

Urban modelling theories and operational models date back to the sixties and seventies, and have been constantly improved since then. It seems therefore that there should be no problem with addressing city sustainability issues. After all, these models claimed to be tools to help planners in choosing the best policies, exactly the same objectives that we need sustainability models to fulfil.

The problem is that urban models have ignored many problems considered today as most pressing. They have not only ignored environmental issues, but also most quality of life issues. If we look at diagrams by Wilson (1981, p.265; 1977, p.3) or Wegener (1994), it is clear that these models focus on land use (understood as location and intensity of activities) and transport problems. The name “urban model” might be then misleading. This does not mean that environmental problems were not modelled at all: they were, but this research area was outside the interests of urban researchers and planners.

One possibility for the way forward is to use old models, integrate them and extend them to include missing components. In order to do this, one should first specify the components to be included in the integrated model, taking the sustainability concept and the new modelling objectives as a point of reference.