STRATEGIC ENVIRONMENTAL ASSESSMENT PERFORMANCE CRITERIA — THE SAME REQUIREMENTS FOR EVERY ASSESSMENT?

Current interpretations of strategic environmental assessment (SEA) revolve around two main ideas. Firstly, SEA is seen as a concept for improving decision making through the assessment of environmental and potentially other impacts, not following any prescribed form, thus being flexible and leaving ample space for different interpretation. Secondly, a more rational view is taken and SEA is regarded a systematic instrument for improving decision making through assessment of the environmental and potentially other impacts, following a prescribed set of procedural stages and possibly other methodological aspects. Adopting the argument of the latter idea, this paper suggests that SEA performance criteria are not equally valid for every SEA, but differ for three distinct SEA types; policy-SEA, plan-SEA and programme-SEA. In order to provide empirical evidence, 25 assessments for transport and spatial/land use policies, plans and programmes (PPPs) are evaluated, based on the performance criteria introduced by the International Association for Impact Assessment (IAIA) at the Glasgow meeting in 1999 and endorsed in November 2001.