Polycentricity, Performance and Planning: Concepts, Evidence and Policy in Barcelona, Catalonia

Despite strong efforts made by scholars to study the polycentric spatial organization of agglomeration in metropolitan areas, there is still no consensus about the conceptualization (i.e., identification and measurement) of polycentricity and its economic, social, and environmental (dis)advantages. Additionally, little is known in the policy realm about how polycentric development can be conceptualized in spatial plans and how the assumed benefits of polycentricity can be realized in planning practice. This is despite the fact that more than 75 percent of recent spatial plans developed for large metropolitan areas in OECD countries consider polycentric development to be the best strategy for managing urban development. It is therefore crucial to gain more insights into the multiple and reciprocal relationships among the polycentric spatial structure of metropolitan areas; their economic, social, and environmental performance; and how these metropolitan areas are planned through the elaboration of spatial plans. A deep understanding of these relationships will help to successfully address impending economic, social, and environmental challenges for people who currently live in metropolitan areas—this includes approximately 50 percent of the world’s population, considering only the non-metropolitan and metropolitan populations of OECD countries in 2014. This issue of A+BE provides valuable insights by conducting research that links knowledge of polycentric constellations and their economic, social, and environmental effects to planning practice and policy in metropolitan areas. Specifically, this book develops policy/discourse analysis to examine how the makers of spatial plans have addressed polycentric development over time. Moreover, this book contributes to the literature by proposing conceptual and empirical frameworks for identifying/measuring polycentricity on the intra-metropolitan scale and for broader testing of the effects of polycentricity on metropolitan performance. Evidence-informed guidelines for spatial development strategies are then provided. These guidelines are built upon the empirical substantiation that centers of a polycentric metropolitan structure are able to foster better performance of a metropolitan area when they are more spatially integrated, bigger, and more proximate to their smaller neighboring cities.OTB \u96 Research for the Built EnvironmentArchitecture and The Built Environmen

Borrowed size, agglomeration shadows and cultural amenities in North-West Europe

It has been argued that the concept of “borrowed size” is essential to understanding urban patterns and dynamics in North-West Europe. This paper conceptualizes this idea and provides an empirical exploration of it. A place borrows size when it hosts more urban functions than its own size could normally support. A borrowed size for one place means that other places face an “agglomeration shadow” because they host fewer urban functions than they would normally support. This paper explores the extent to which size and function are related for places in North-West Europe and tries to explain why one place borrows size while the other faces an agglomeration shadow by examining the position of places within the regional urban system. The presence of urban functions was approximated using high-end cultural amenities. We conclude that the largest places in their functional urban area (FUA) are better able to exploit their own mass. The largest place in a FUA is also better able to borrow size from nearby places and from (inter)national urban networks than the lower-ranked places

¿Cap a un sistema de metròpolis espanyoles policèntriques? Evolució de la influència dels subcentres en la distribució de la població

En el decurso de las últimas décadas el crecimiento de las áreas metropolitanas de los países que primero se industrializaron ha estado dominado por la descentralización tanto de la población como del empleo. Dichos procesos de descentralización se han verificado fundamentalmente bajo un modelo de crecimiento por dispersión y, en menor medida, por policentrismo. En este artículo se intenta comprobar si ese patrón es igualmente válido para las siete principales metrópolis españolas, que a pesar de tener tamaños y estructuras muy disímiles, han experimentado recientemente crecimientos significativos. A tales efectos se analizan los cambios en la distribución espacial de la población y se comprueba, mediante modelos econométricos, la capacidad de los subcentros de empleo para organizar en su entorno la densidad demográfica. Los análisis han revelado dos paradigmas divergentes de áreas metropolitanas. El primero, que caracteriza a las áreas fundamentalmente monocéntricas, evoluciona mediante una expansión del centro metropolitano (a pesar de que su núcleo más central se funde) y una explosión fragmentada y desestructurada en la ultraperiferia metropolitana. El segundo, que caracteriza a las áreas con un mayor nivel de policentrismo, evoluciona mediante una expansión más tímida del centro metropolitano y más vigorosa de los subcentros y sus periferias más inmediatas. Puede decirse, por tanto, que existe una divergencia en los modelos de urbanización de las principales metrópolis españolas.En el decurs de les últimes dècades el creixement de les àrees metropolitanes dels països que primer es van industrialitzar ha estat dominat per la descentralització tant de la població com de l'ocupació. Aquests processos de descentralització s'han verificat fonamentalment sota un model de creixement per dispersió i, en menor mesura, per policentrisme. En aquest article s'intenta comprovar si aquest patró és igualment vàlid per a les set principals metròpolis espanyoles, que tot i tenir mides i estructures molt diferents, han experimentat recentment creixements significatius. A tals efectes s'analitzen els canvis en la distribució espacial de la població i es comprova, mitjançant models economètrics, la capacitat dels subcentres d'ocupació per a organitzar en el seu entorn la densitat demogràfica. Les anàlisis han revelat dos paradigmes divergents d'àrees metropolitanes. El primer, que caracteritza les àrees fonamentalment monocèntriques, evoluciona mitjançant una expansió del centre metropolità (tot i que el seu nucli més central es fon) i una explosió fragmentada i desestructurada en la ultra perifèria metropolitana. El segon, que caracteritza les àrees amb un major nivell de policentrisme, evoluciona mitjançant una expansió més tímida del centre metropolità i més vigorosa dels subcentres i les seves perifèries més immediates. Es pot dir, per tant, que existeix una divergència en els models d'urbanització de les principals metròpolis espanyoles.In the course of the last decades the growth of metropolitan areas in the first industrialized countries has been dominated by the decentralization of both population and employment. These processes of decentralization have been verified primarily under a dispersion growth model and to a lesser extent by polycentrism. This article attempts to verify whether this pattern also applies to the seven major Spanish metropolitan areas, which despite having very different sizes and structures, have recently experienced significant growth. For this purpose is have analyzed the changes in the spatial distribution of the population and verified through econometric models the ability of the employment subcentres to organize population density in the surroundings. Analysis has revealed two divergent paradigms of metropolitan areas. The first, which characterizes the mainly monocentric areas, evolves through an expansion of the metropolitan centre (despite its central nucleus melts) and an explosion fragmented and unstructured in the metropolitan remoteness. The second characteristic of areas with a higher level of polycentrism, evolves through a shyer expansion of the metropolitan centre and most vigorous of the subcentre and its immediate periphery. It may be said, therefore, that there is a divergence in patterns of urbanization of the main Spanish metropolitan areas.Peer Reviewe