Environment and Planning B: Urban Analytics and City Science

The increasingly complex living environment poses challenges in everyday life that traditional urban planning cannot meet. We argue that the methodology called the user-sensitive service design within urban planning is viable for many stakeholders in a situation where the infrastructure of everyday life is shattering and the uncertainty and ambiguity of the planning process and outcomes are prevailing. Our aim is to present the methodology and its application in the planning and development of digitised services in a neighbourhood of Helsinki. The methodology turns out to be a hybridiser and a bridge builder that embeds urban planning in the local context. In addition, it is a vehicle for transferring planning content to the phases of implementation and use, resulting in the emergence of glocal digital spaces.

Lock-in, the escalating commitment of decision makers to an ineffective course of action, has the potential to explain the large cost overruns in large-scale transportation infrastructure projects. Lock-in can occur both at the decision-making level (before the decision to build) and at the project level (after the decision to build) and can influence the extent of overruns in two ways. The first involves the ‘methodology’ of calculating cost overruns according to the ‘formal decision to build’. Due to lock-in, however, the ‘real decision to build’ is made much earlier in the decision-making process and the costs estimated at that stage are often much lower than those that are estimated at a later stage in the decision-making process, thus increasing cost overruns. The second way that lock-in can affect cost overruns is through ‘practice’. Although decisions about the project (design and implementation) need to be made, lock-in can lead to inefficient decisions that involve higher costs. Sunk costs (in terms of both time and money), the need for justification, escalating commitment, and inflexibility and the closure of alternatives are indicators of lock-in. Two case studies, of the Betuweroute and the High Speed Link-South projects in the Netherlands, demonstrate the presence of lock-in and its influence on the extent of cost overruns at both the decision-making and project levels. This suggests that recognition of lock-in as an explanation for cost overruns contributes significantly to the understanding of the inadequate planning process of projects and allows development of more appropriate means.

Fractal analysis offers potential as a tool for evaluating the visual qualities of street vistas. In this paper we outline the concept of fractal dimension as a measure of texture in images of built form and describe a methodology for comparing fractal dimension with perceptions of visual quality in street vistas. We find that a positive relationship exists between levels of fractal dimension and judgments of visual quality in street vistas and outline the applications that this relationship may have.

When the known properties of the dynamics of nonlinear systems are reviewed in the context of urban and regional modelling, it is argued that this provides an important new perspective for planners—analogous to the role of DNA in biology. As a preliminary, it is shown that effective modelling of urban and regional dynamics, particularly with a view to policy and planning applications, demands the articulation of a hierarchy of models. It is then possible to identify the structural ‘DNA’ for various layers which determine the dynamics and possible paths of development. This in turn allows the development of a ‘genetic planning’ concept by analogy with ‘genetic medicine’.

Using fractal theory and urban land-use maps for 1949, 1959, 1980, and 1996, this study is devoted to analyzing the evolutionary features of urban form and land-use structure in Hangzhou, China. We find that self-similarity exists in both the built-up area and the municipal area, and fractal properties tend to become better defined with time. The fractal dimension of each type of land use is less than that of all land use. From 1980 to 1996, the fractal dimensions of residential, industrial, and external transport increased while those of educational and virescent land use decreased, indicating that partial degradation accompanied holistic optimization during the process of Hangzhou's self-organizing evolvement. The mechanisms of the spatiotemporal evolution of urban form in Hangzhou are discussed, including socioeconomic development and the dispersal or concentration of activities. The Tandabing approach to urban spatial expansion, the Jianfengchazhen approach to urban construction, and a top-down urban management style led to differences in fractal evolution between Chinese and Western cities.

There are increasing concerns regarding the quality of urban public spaces. Wind is one important environmental factor that influences pedestrians' comfort and safety. In modern cities there are increasing numbers of high constructions and complex forms which can involve problems of significant wind discomfort around these buildings. Architects and town planners need guidelines and simple design tools to take account of wind in their projects. This paper reports the progress made in using computational fluid dynamics (CFD) simulations for assessing wind comfort in urban planning. Fluent software was validated for wind studies in urban environments by comparing CFD simulation results with published wind-tunnel tests. This validation shows that mean wind velocities around buildings can be simulated numerically with a very high degree of accuracy. On the basis of the results of a large number of CFD simulations, a methodology and simple graphical tools were developed to quantify critical wind speeds around buildings. In practice these should help architects and town planners when designing our built environment. Moreover, this study shows how numerical modelling is now a high-performance tool for developing useful guidelines and simple design tools for urban planners.

Spatial distance is a critical component of theories across the social, natural, and information sciences, but too often the methods and metrics used to describe spatial distance are implicit or underspecified. How distance is measured may influence model results in unanticipated ways. We examined the differences among distances calculated in three ways: Euclidean distances, vector-based road-network distances, and raster-based cost-weighted distances. We applied these different measures to the case of the economic value of open space, which is frequently derived using hedonic pricing (HP) models. In HP models, distance to open space is used to quantify access for residential properties. Under the assumption that vector-based road distances better match actual travel distance between homes and open spaces, we compared these distances with Euclidean and raster-based cost-weighted distances, finding that the distance values themselves differed significantly. Open-space values estimated using these distances in hedonic models differed greatly and values for Euclidean and cost-weighted distances to open space were much lower than those for road-network distances. We also highlight computational issues that can lead to counterintuitive effects in distance calculations. We recommend the use of road-network distances in valuing open space using HP models and caution against the use of Euclidean and cost-weighted distances unless there are compelling theoretical reasons to do so.

A web-based collaborative-argumentation mapping experiment, which was used as part of a planning process in the city of Tampere, Finland, revealed a need for analytical tools to interpret the users' meaning making with this particular public participation GIS instrument. The main reason for this was the complexity of mediated interaction between different actors in and by means of the application: written comments, graphic symbols, and aerial photographs were combined to make meaning in particular context-specific situations. An analytical framework is discussed; it is shown to have the potential to grasp this type of signification process by studying the dynamics of different semiotic means and the production of discourse and settings in practice.

In this paper a scenario study of the residential land-use development in the Elbe River Basin is presented. The study uses an approach that empirically determines suitability maps for the application within a land-use-change model. Recent urbanisation processes are explained in the first step and are used in simulations of future land use in the second step. Binomial logistic regression analysis is applied in an analysis of the location characteristics influencing residential land-use change. Estimation results are adapted and used as weights in the calculation of suitability maps, which consist of the location characteristics of residential land-use change. Including policy maps in suitability calculations allows important spatial restrictions to be accounted for and enables the impact of spatial planning on the allocation of residential developments to be analysed. The suitability maps are further applied to the Land Use Scanner model to simulate spatially explicit residential land-use developments in the Elbe River Basin. Results of this study show that empirically determined suitability maps used in models of land-use change can contribute to the operational use of scenario studies in political discussion support. Considerable differences in applied policy maps in terms of their contribution to the sustainable development of residential and use are discussed.

Past research has revealed that governments are often tempted to underestimate the costs and overestimate the benefits of infrastructure projects. However, an analysis of local-government estimates and accounts reveals that servicing land by local authorities in the Netherlands is an exception to this general phenomenon. The profits made by local authorities from land development are growing, while the costs, revenues, and results are, on average, underestimated by local authorities. This may have consequences for the explanation of budget overruns and the solutions that may be effective in countering this problem. It is not always necessary for there to be one single moment in the planning process at which a fully informed choice can be made; an alternative is to leave room for flexible, piecemeal decision making.

Fractal dimension is an index which can be used to characterize urban areas. The use of the curve of scaling behaviour is less common. However, its shape gives local information about the morphology of the built-up area. This paper suggests a method based on a k-medoid for clustering these curves. It is applied to forty-nine wards of European cities, and shows that the curves add interesting intraward information to our knowledge of the spatial variation of the urban texture. Moreover, morphological similarities are observed between cities: living, architectural, and planning trends are not specific to individual cities.