Conformance in land-use planning: the determinants of decision, conversion and transgression

tOver recent decades, urban areas have expanded into agricultural areas. To contain outward spatialexpansion and regulate urbanisation, policy-makers should continually review and evaluate their plans.Planners may use conformance-based approaches in which they examine the relationships between plansand physical outcomes.This paper analyses land-use changes and their links to seventeen municipal master plans approvedduring the 1990s in the Lisbon Metropolitan Area. We evaluated the conformity of land-use changes tomunicipal master plans and identified the major measurable factors conducive to land allocation, con-forming changes, and nonconforming changes. We created three logistic-regression models to estimatethe probabilities of plot development in three different land-use pathways: (i) intended for developmentwithin municipal plans (conversion decision path); (ii) subsequently converted in conformity with theplan (conforming conversion path); (iii) converted in disagreement with the plan which had assumedthe land plot could not be developed (transgression path).Results show that previous urban dynamics and distances from Lisbon are the main drivers of all models.Transport networks affect policy decisions−as well as conforming and transgressive conversions. Thepolitical orientations of local governments significantly influence land-use evolution. Land-preservationpolicies and municipal decisions do not reduce transgression.This study is a contribution to the body of research literature regarding the evaluation of plan imple-mentation. It is shown how regression models can be used to refine conformance-based analyses. Morethan simply quantifying nonconformity, its determinants are identified.