The sustainable urban development is a subject of interest for regional policy makers and it needs appropriate
assessment based on futile instruments for research, and for practical reasonsl (planning and decision making).
Even if the sustainability’s attainment is a research topic field for academia and urban planners and managers
and, as well, an ambitious goal for any resource administrator, yet there is no precise way of defining and
measuring it. The sustainability of the urban development policy implies multiple and diversified aspects from
rational exploitation of the local resources and well-structured workforce to environmental issues, endowment of
modern urban facilities and infrastructure elements. As the urban sustainability is measured using a multitude of
basic indicators, needing proper information to make long term management decision and planning, the subject is
treated with fuzzy setsseen as an appropriate manner to deal with ambiguity, subjectivity and imprecision in the
human reasoning when processing large volumes of data, eventually unstructured and complex. The paper
proposed a modeling approach based on fuzzy sets inspired by the SAFE (Sustainability Assessment by Fuzzy
Evaluation), a model which provides a mechanism for measuring development sustainability. The papers intends
presenting a quantitative methodology in assessing the potential sustainability of urban development (in terms of
adequacy) by pointing the failures in pursuing trends that are associated to a robust growth in the urban areas.
The advantages of such approach are derived from taking into account the multi-criteria and uncertainty facets of
the phenomenon; also, having in mind that the sustainability remains a non-straight-cut concept, being vaguely
defined it implies a non-deterministic character by using the fuzzy set logic. The proposed model is designed to
assess the divergence from desired trajectories, the weak point in reaching indicators’ target (as they are
commonly regardedd as appropriate in what is understood as a good practices), it may then be addressed for
policy makers in indicating some action measures in urban administration as they intendenly strive towards
increasingly sustainable development on the long term.