Planning for the new European metropolis: functions, politics, and symbols/Metropolitan regions: functional relations between the core and the periphery/Business investment decisions and spatial planning policy/Metropolitan challenges, political responsibilities/Spatial imaginaries, urban dynamics and political community/Capacity-building in the city region: creating common spaces/Which challenges for today's European metropolitan spaces?

Why is it so difficult to address the emerging problems of European city-regional spaces? For almost three decades, planners and geographers have consistently mapped the changing social and economic form of cities. Two decades of continuous urban expansion and, more recently, transformation of the urban core, have blurred the existing categories of “suburbia” and “urban core”. Suburbia has changed dramatically from a homogeneous habitat of the middle class to a much more variegated and highly specialised, fragmented urban landscape. The urban core experienced dramatic changes as well. Nowadays, the city region is best portrayed as an urban archipelago of distinct economic and social spaces, consisting of highly specialised islands that are juxtaposed. Yet, despite these observations, and despite the extensive knowledge of the patterns that are emerging in urban and regional areas, European city-regional spatial policies still seem to have problems to plan for this new configuration. Institutional structures and practices remain geared towards the radial (core-centric) urban model of the past, which put outer areas in a dependent position in their relations with core cities. This historical pattern is evident in a range of issues, from social and housing policies to infrastructural policies oriented to serve core city economies. Peripheries are thus seen either as satellites or anchors of core cities’ development. This largely prevents planners and politicians from finding adequate responses to problems like social inequality, spatial disconnection and uneven economic development (Janssen-Jansen & Hutton, 2011; Kantor, Lefevre, Saito, Savitch, & Thornley, 2012). Whether one looks at issues of governance, environment, social polarisation or transport, it is hard to find a “problem owner” addressing these issues at a scale sufficient to grasp the changing urban landscape. This Interface argues that today’s European urban landscapes reveal a consistent change in the functional, political and symbolic relations between the core and the periphery, and that these changes need to be understood in their institutional context before planning interventions can be made effectively. We propose to structure the debate around three statements. First, there is a need to understand the nested economic driving forces and place-specific opportunities in the decisionmaking around key functions. Second, the urban transformation has led to a new political landscape with increasing interdependencies, which have resulted in asymmetric relationships that call for new solutions in regional policy-making. Third, the emerging city-regional spaces are increasingly reflected in the symbolic representation of new city-regional policies but are struggling to get adequate support to enable effective adaptation of the traditional view of cities. A response to the current problems of metropolitan change cannot come about without a fruitful interaction between the exercise of “interpreting” urban change and the task of “addressing” it through policy-making. The three aforementioned statements aim to provide fertile ground for discussing the theory and practice of planning urban transformations. In this Interfacewe attempt to emphasise the common elements of academic works oriented in explaining metropolitan dynamics, combining this with reflections on the past, present and future possibilities of action. In line with