Land-use/transport Interaction Models as Tools for Sustainability Impact Assessment of Transport Investments: Review and Research Perspectives

Interest in the appraisal of the sustainability impacts of transport policies has grown the last
few years, expressing the need for a balanced treatment of economic, environmental and
social impacts. This paper represents a first step in creating a framework for Sustainability
Impact Assessments; it will also review operational land-use/transport interaction models as
assessment tools. An in-depth analysis of the potential impacts of land-use and transport
policies, and scenarios, on the economy, society and the environment will present new
challenges to land-use/transport interaction models. The first challenge is related to
modelling behaviour: i.e. the model should estimate land-use, transport and accessibility
impacts in a theoretically sound and consonant manner, and consistently link the full set of
(long-term) land-use and (short-term) travel-behavioural responses to these policies. The
second challenge is to improve methodologies to (better) include the wider (macro-)economic
effects and the passive values. The third challenge is to generate more knowledge for
understanding ecological and social impacts, and for the development of related indicators
and methodologies to calculate them. A fourth, and final, challenge is related to the
presentation and integration of the sustainability impacts, not only including the economic,
ecological and social impacts, but also finding the ‘right’ balance between them. Although
recent model developments facilitate a far more comprehensive analysis than is common practice today, there is certainly a need for theoretical and practical research for conducting
Sustainability Impact Assessments of land use and transport policies and scenarios.