Environment and Planning B: Urban Analytics and City Science

In this paper we employ readily available categories of public data, rarely used in the literature on racial segregation, to scrutinise three research questions about the proposition of Lai and Yu (2001 Environment and Planning B: Planning and Design 28 295–314) that statutory zoning, which discriminates against a certain class of citizens, can be a form of price control. The key findings are that there was a large Chinese population on the Peak in Hong Kong even when the law did not allow Chinese people to own property there, that the process of acquiring European properties for residential purposes after the removal of the law was slow, and the Peak remained predominantly European until the 1980s. In other words, the factual evidence supports the argument that racially discriminatory zoning in the Peak District had not been predicated on racial animosity or aversion. The residential history of the Peak and another exclusively European housing enclave in Shek O established prewar under company law points towards the reality that the attempt to prevent the Chinese from buying properties in certain areas of Hong Kong was driven by idiosyncratic demands for a particular housing style. These two case studies demonstrated that contractual planning is much more capable of preserving the character of a neighbourhood than obligatory planning by edict. Some economic reasons behind the resilience of planning by mutual agreement and their implications for sustainable development are discussed.

Urban sprawl is one of the main factors underpinning the changes observed in European landscapes and environment. The analysis of a phenomenon of this sort is conditioned in large part by the availability of documented urban databases, validated by experts and regularly updated. From this point of view the Urban Morphological Zones (UMZs) produced by the European Environment Agency form an important prospect for the future. However, it is essential to set the results of this highly automated approach against the already well-documented national databases. In this paper we investigate the validity of the UMZs for reflecting urban entities, through comparisons with Danish, French, and Swedish national databases for year 2000. We propose a method based on a matching protocol between UMZs and national agglomerations which is based on conceptual and technical choices, in order to take account of the complexity of urban objects. Two main results are pinpointed. On a global level the UMZ database is fully adequate for comparing levels of urbanisation among states. There is no systematic bias in the delineation of urban areas by the UMZs and total urban populations differ only by 5% to 8%. Conclusions should be more cautious when the scale of observation is the town or city itself. In France, mean differences are as small as in Denmark and in Sweden, but certain large agglomerations display marked divergences that depend partly on local urbanisation patterns. We propose a typology of deviations which could be useful for the majority of states that do not have a national morphological urban database, in particular in Eastern Europe.

The causality issue has become one of the key questions in the debate over the relationship between the built environment and travel behavior. Since a residential self-selection effect exists, it is important to know if the observed influence of the built environment on travel behavior diminishes substantially once we control for self-selection. Using 5537 adult respondents to the 2006 Great Triangle Travel Survey in North Carolina, this study applied the propensity score matching approach to identify the causal effect of density on travel behavior and the relative contribution of self-selection to travel behavior. The results showed that, after removing self-selection bias, residents living in high-density neighborhoods travel, on average, 3.31 fewer miles per person per day than those who live in low-density neighborhoods. Self-selection effects account for 28%, 64%, and 49% of the observed influences of density on personal miles travelled, driving duration, and transit duration, respectively. We also found that different modeling approaches produce different point estimates, and that interval estimates of treatment effects tend to have a large variation. This points to a caveat of using point estimates to evaluate the impacts of the built environment on travel behavior.

A reliable and accurate short-term traffic forecasting system is crucial for the successful deployment of any intelligent transportation system. A lot of forecasting models have been developed in recent years but none of them could consistently outperform the others. In real-world applications, traffic forecasting accuracy can be affected by a lot of factors. Impacts of long-term changes to traffic patterns to short-term traffic forecasting are profound and this can easily make an existing forecasting system outdated. Therefore, it is very important for forecasting systems to detect long-term changes in traffic patterns and make updates accordingly. This paper presents a new forecasting mechanism, in which a dynamic hybrid approach is taken and self-learning ability is enhanced. Results of a case study show the proposed approach is feasible in enhancing the adaptability of traffic forecasting systems.

The concept of style is relevant for both the analysis and synthesis of designs. New styles are often formed by the adaptation of previous ones based on changes in design criteria and context. A formal characterization of style is given by shape grammars, which describe the compositional rules underlying a set of designs. Stylistic change can be modelled by grammar transformations, which allow the transformation of the structure and vocabulary of a grammar that is used to describe a particular style. In order for grammars to be useful beyond a single application, they should have the capability to be transformed according to changing design style needs. Issues of formalizing stylistic change necessitate a lucid and formal definition of style in the design language generated by a grammar. Furthermore, a significant aspect of the definition of style is the representation of aesthetic qualities attributed to the style. We focus on grammars for representing and generating styles of design and review the use of grammar transformations for modelling changes in style and design language. We identify a gap in knowledge in the representation of style in grammars and in driving strategic style change using grammar transformations.

The planning practice of focusing most rural development within larger settlements has failed to achieve goals of rural activity colocation. In a society where quality of opportunity has become dominant in location decisions, a broader imaginative perspective than the physical proximity of functions is required if meaningful activity colocation is to occur. The extent to which residents and employees can be encouraged to localise their activity is explored through case studies of three very different small towns within the English county of Norfolk. Although not of universal appeal, small towns provide an important niche for many rural actors. Rather than abandoning policy endeavours, there is potential to improve their effectiveness by ensuring that the possible benefits arising from the colocation of activity are realised. By adopting a more flexible approach to policy application, utilising complementary conceptions which are attentive to the specific characteristics of individual places, potential exceptions to policies of development concentration can be identified. However, in the UK context ongoing cutbacks in local authority budgets are likely to prejudice the conduct of the type of fine-grained local policy development required to achieve these objectives.

The use of housing market areas (HMAs) has become an important element of spatial planning and regional strategies in the UK. The use of HMAs also fits well within an era of market-responsive planning. In this paper we identify deficiencies in the existing planning advice for defining them in England and Scotland. The result is that the HMAs that have been produced lack consistency and are too often constrained to administrative boundaries for policy convenience. We also review existing academic studies and their theoretical underpinning. On the basis of this analysis we propose a rethink on defining HMAs, arguing for a tiered approach developed consistently on a national basis. We then develop a comprehensive tiered geography of HMAs for the whole of England. The advantages of this approach for spatial planning, and the prospects for its application, are then outlined.

In this paper we assess the efficacy of a dynamic adaptive planning (DAP) approach for guiding the long-term development of infrastructure. The efficacy of the approach is tested on the specific case of airport strategic planning. Utilizing a fast and simple model of an airport, and a composition of small models that can generate a wide spectrum of alternative futures, the performance of a dynamic adaptive plan is compared with the performance of a static, rigid implementation plan across a wide spectrum of conceivable futures. These computational experiments reveal that the static rigid plan outperforms the dynamic adaptive plan in only a small part of the spectrum. Moreover, given the wide array of possible futures, the dynamic adaptive plan has a narrower spread of outcomes than the static rigid plan, implying that the dynamic adaptive plan exposes planners to less uncertainty about its future performance despite the wide variety of uncertainties that are present. These computational results confirm theoretical hypotheses in the literature that DAP approaches are more efficacious for planning under uncertainty.

Visioning exercises using computer-based environmental visualization hold significant promise for communicating information and engaging communities in the development and review of planning proposals. The field of visualization research and practice has achieved significant advances in computer technology to the point where it is now possible to represent alternative planning and engineering scenarios with a high degree of photographic realism, data-driven accuracy, and spatial and temporal interactivity. Despite the noteworthy benefits and developments in the field of environmental visualization technology comparatively little research has investigated how visualizations are used in urban planning practice. In particular, research is needed that examines how visualization presentation is affected by the social context of planning practice and the independent judgment of the preparer, which may in turn influence plan evaluation and decision making. In this paper I discuss the significance of visualization for urban planning and design and present the results from a study where students and representatives of a citizen-led planning committee evaluated four visualization presentation styles according to perceived realism, credibility and preference for the visualized environmental plans.

The availability of high-resolution remote sensing imagery brings both opportunity and challenge to environmental designers and planners in obtaining high-quality landscape information for better design and planning decision making. To meet the challenge, in this paper we introduce a comprehensive approach to measuring urban vegetation data detailed to single patches of trees or shrubs and single patches of lawn or grass with multisource remote sensing imageries. Methodologically, the approach integrates advanced geospatial technologies to achieve the research objective. First, an automatic registration algorithm is applied to align an unorthorectified QuickBird satellite multispectral imagery to a high-resolution United States Geographical Survey orthoimage. Next, an image segmentation process extracts landscape objects from such multisource data for further object-based image classification. Third, the approach takes advantage of the strong power of a group of prioritized spectral, geometric, topological, and thematic image object features to produce satisfactory classification results. The approach was tested in the Oakland Metropolitan Area in California, USA and was assessed with both groundtruthing and imagetruthing data. The paper concludes with a discussion on the potential applications of both the approach and the generated data in environmental design and planning.

In this paper we propose an approach to identify the spatial policy parameters (termed the implementation intensity reflecting planning controls on corresponding spatial constraint) associated with a predefined alternative plan, namely, a predefined-binary urban form. During plan implementation, the alternative plan cannot be fully realized in some cases due to practical urban growth driven by both institutional forces and market incentives, which are comprehensive and complex. Few researchers have investigated spatial policies appropriate for an alternative plan. We aim to propose a novel approach incorporating constrained cellular automata and regionalized sensitivity analysis, a method for global sensitivity analysis to calculate the realization possibility and identify the spatial policy parameters for an alternative plan. This approach is first tested in a virtual space with four predefined urban forms and various point, line, and polygon spatial constraints, with both positive and negative impacts on urban growth. Finally, the approach is also tested in the Beijing Metropolitan Area to identify the required spatial policy parameters for four alternative plans with seven spatial constraints.