Environment and Planning B: Urban Analytics and City Science

Conventional approaches to measuring accessibility benefits are not capable of fully measuring the total accessibility benefits of integrated land-use-transport strategies, in which both land-use and transport changes form part of the policy strategy. In this paper a comprehensive methodology for analysing accessibility impacts and accessibility benefits, which is based on location-based and utility-based accessibility measures within an integrated land-use-transport interaction modelling framework, is described and applied in a case study. The case study examines the accessibility benefits and related user benefits of intensive mixed-use strategies aimed at increasing the density and diversity of activities around railway stations for the Randstad area of the Netherlands for the 1996–2030 period. A heavy concentration of activities near railway stations is shown to result in decreasing marginal returns for public-transport users and disbenefits for car users.

The recent pursuit of regional planning agendas in England has coincided with a strong push from the government towards an evidence-based, information-intensive approach to policymaking, with the increased use of statistical indicators to inform and evaluate emerging regional policies. In this paper we aim to examine the monitoring arrangements, and the way indicators are used, in the development and monitoring of key regional strategies (Regional Planning Guidance, Regional Economic Strategies). The idea is to examine indicator usage and monitoring arrangements from a political–managerial perspective through an exploration of the realm of rational–technocratic activities of monitoring within the institutional environment of Regional Planning Bodies and Regional Development Agencies. Following a review of academic literature, we explore the regional intelligence management and the monitoring arrangements of the two key regional strategies in each of the English regions. The analysis is based on documentary and web-based reviews as well as in-depth interviews conducted with key regional actors.

One of the major challenges to providing full-rate digital subscriber line (xDSL) access to residential customers in rural or remote locations is the use of existing copper infrastructure. First, copper is not particularly good for moving high frequencies over extended distances. Second, much of the existing copper in the United States is of diminished quality. Third, digital loop carriers, bridge taps, load coils, and ambient interference negatively impact data transmission. Because of these problems, the geographic reach of xDSL services is limited. To combat this limitation, providers are installing remote digital subscriber line access multiplexers (RDSLAMs). RDSLAMs seek to maximise the amount of demand covered for a peripheral neighborhood and aggregate this data traffic onto a fiber optic connection for transport back to the central office (CO) for switching. Although this is more feasible than constructing a new CO, acquiring the rights of way and installing fiber is expensive. The purpose of this paper is to examine the complexities associated with locating RDSLAMs in a competitive telecommunications market through the use of an integer programming model—the remote access hierarchical assignment problem—and a geographic information system. Pertinent policy and technology related issues in residential broadband deployment and their impacts on high-speed services such as xDSL are highlighted.

The network metaphor in the analysis of urban and territorial cases has a long tradition, especially in transportation or land-use planning and economic geography. More recently, urban design has brought its contribution by means of the ‘space syntax’ methodology. All these approaches-though under different terms like ‘accessibility’, ‘proximity’, ‘integration’ ‘connectivity’, ‘cost’, or ‘effort’-focus on the idea that some places (or streets) are more important than others because they are more central. The study of centrality in complex systems, however, originated in other scientific areas, namely in structural sociology, well before its use in urban studies; moreover, as a structural property of the system, centrality has never been extensively investigated metrically in geographic networks as it has been topologically in a wide range of other relational networks such as social, biological, or technological ones. After a previous work on some structural properties of the primal graph representation of urban street networks, in this paper we provide an in-depth investigation of centrality in the primal approach as compared with the dual one. We introduce multiple centrality assessment (MCA), a methodology for geographic network analysis, which is defined and implemented on four 1-square-mile urban street systems. MCA provides a different perspective from space syntax in that: (1) it is based on primal, rather than dual, street graphs; (2) it works within a metric, rather than topological, framework; (3) it investigates a plurality of peer centrality indices rather than a single index. We show that, in the MCA primal approach, much more than in the dual approach, some centrality indices nicely capture the ‘skeleton’ of the urban structure that impacts so much on spatial cognition and collective behaviours. Moreover, the distributions of centrality in self-organized cities are different from those in planned cities.

The technology for determining the geographic location of cell phones and other handheld devices is becoming increasingly available. It is opening the way to a wide range of applications, collectively referred to as location-based services (LBS), that are primarily aimed at individual users. However, if deployed to retrieve aggregated data in cities, LBS could become a powerful tool for urban analysis. In this paper we aim to review and introduce the potential of this technology to the urban planning community. In addition, we present the ‘Mobile Landscapes' project: an application in the metropolitan area of Milan, Italy, based on the geographical mapping of cell phone usage at different times of the day. The results enable a graphic representation of the intensity of urban activities and their evolution through space and time. Finally, a number of future applications are discussed and their potential for urban studies and planning is assessed.

As exurban development spreads throughout fire-prone areas of the western United States, the threat of wildfire to life and property grows. To address this threat, wildfire mitigation, such as mechanical thinning, often takes place in areas close to exurban development. This study demonstrates the utility of spatially explicit dynamic models to understand better where the wildland–urban interface is, how it might change in the future, and how this might affect which land would be prioritized for mechanical thinning. Specifically, a model (WHAMED) is presented that forecasts the prioritized locations for future mechanical thinning as a function of projected exurban development in the montane zone of Boulder County, CO. To predict exurban development, WHAMED uses a cellular automata model with rules derived from statistical models of historical exurban development. The study tests two general sets of criteria for prioritizing mechanical thinning, that of the Community Protection Zone and the Healthy Forests Restoration Act of 2003. The study shows that under any forecast of exurban development, and under either set of criteria, prioritized land for mechanical thinning is set to expand primarily on US Forest Service land. Methodologically, the study illustrates the importance of making variability transparent and of providing multiple methods of model validation.

The political and spatial dimensions of US metropolitan areas are eminently interconnected through a recurring cycle of fragmentation and sprawl. In this paper we demonstrate the cycle at work by refining a land-use model developed in a previous paper and applying it to a national dataset of metropolitan counties. The recursive simultaneous-equations model is structured around five-year intervals, and enables us to observe how the political landscape (urban development patterns) at time t − 5 affects spatial outcomes (municipal fragmentation) at time t. The results suggest that regulatory failure may bear as much fault for urban sprawl as the more commonly cited market failures, and that it may therefore be worthwhile to shift the focus of the sprawl/antisprawl debate from its physical to its political dimensions. Future research should focus on identifying the systematic nature of sprawl and, as an extension, the various policy levers that may be used to mitigate its negative consequences. The paper improves on previous research in four key ways: by describing the underlying theory in greater detail; by rounding out the recursive relationship; by enriching the set of interdependent variables; and by expanding the geographic scope of the model. Its primary contribution is to deepen the pool of empirical evidence linking political structure to patterns of growth and change in US metropolitan regions.