Environment and Planning B: Urban Analytics and City Science

We are interested in the generation of distinguishing place or route descriptions for urban environments. Such descriptions require a hierarchical model of the discourse, the elements of the city. We postulate that cognitive hierarchies, as used in human communication, can be sufficiently reflected in machine-generated hierarchies. In this paper we (a) propose a computational model for the generation of a hierarchy of one of these elements of the city—landmarks—and (b) demonstrate that a set of filter rules applied on this hierarchy derives distinguishing route descriptions from spatial context.

Distance constraint is a major concern in many spatial analyses. Buffering is one of the proximity techniques in GIS most commonly used to address this constraint. I introduce shape-based point buffering, an anisotropic and variable-distance buffer generation method conformal to the original polygons. In contrast with isotropic fixed-distance buffering, shape-based buffering is defined using a relative distance (percentage) instead of a real unit (for example, meters), and it allows all buffered boundaries to be formed at the same time. The construction and implementation of the buffering method are described below. Three emergency-response scenarios are designed to demonstrate potential applications of this buffering method, including a shape-based fixed-percentage buffer calculation and space distribution, a shape-based variable-percentage buffer region, and a reverse calculation of the task schedule from a probability surface constructed from shape-based buffers. Limitations of the method are discussed. The method has potential applications in emergency preparedness and planning to better address fairness issues when a geographic area must be zoned arbitrarily.

This paper presents a quasi-3D cellular automaton (CA) simulation model of cities. A 2D CA model includes a cell attribute that represents building height information. Dynamic processes are depicted using four parameters: initial building coverage, interaction with adjacent neighborhood, inertia, and noise. These parameters can assume simple economic interpretation. Some combinations of values of the parameters result in cities that experience paths of convergent growth. Some values lead to cities that experience phase transitions. We suggest a typology of resulting urban patterns and note the emergence of spatial clusters of high-rise buildings.

Understanding the stop-making behavior of commuters is important for planners and policy makers in their efforts to improve travel demand models and to develop transportation demand management strategies. Previous studies have identified various determinants of commuters' stop generation. However, the way in which accessibility affects stop-making decisions is not clear. Further, few studies have considered the impacts of attitudes and predispositions, which extensively influence travel behavior. Using 1256 commuters in Northern California, this study investigates the influences of accessibility and attitudes on evening commute stop-making behavior. Based on a bivariate selection model, we found that the propensity of workers to make stops is dependent on their attitudes, work-related attributes, neighborhood accessibility, and sociodemographic characteristics, whereas the frequency of trip chaining is primarily determined by sociodemographic characteristics. Accordingly, if we offer commuters opportunities to stop through land-use and transportation policies, they may tend to do so, but the intensity of chaining behavior depends on household needs, the individual's role in the household, and personal time constraints.

So far, the literature on Internet adoption by retailers has paid little attention to spatial variables. Using data on approximately 12 000 independent retailers, we investigate the geographical diffusion of Internet strategies in the Netherlands. In particular, we examine to what extent Internet adoption differs among shopping centers, cities, and regions, while accounting for organizational variables. Results suggest that independent retailers at city and village centers are more likely to adopt information-only and online sales strategies than independents located at shopping centers at the bottom of the retail hierarchy. Furthermore, independent retailers in large(r) cities have a higher probability of adopting the Internet than their counterparts in small(er) cities. On the regional level, the likelihood of Internet adoption is higher for independent retailers in core regions than for independents in the periphery. Thus, geography seems to matter for Internet adoption by independent retailers.

This paper investigates the impact of pedestrian environments on walking behavior, and the related choice of travel path for transit riders. Activity logs from trip surveys combined with transit-route and land-use information are used to fit discrete-choice models of how riders choose among multiple paths to downtown destinations. The work illustrates (1) how the quality of pedestrian environments along transit egress paths affects transfers inside a transit system, and (2) how the impedance of transferring affects egress walking path choices. The use of GIS techniques for path-based spatial analysis is key to understanding the impact of pedestrian environments on walking behavior at the street level. The results show that desirable pedestrian environments encourage transit riders to choose paths that are ‘friendlier’, even if they involve more walking after leaving transit. Policy implications for land-use planning and transit service planning are discussed.

Access coverage is important in public transit planning, as this is the means by which service is provided to riders. In fact the proximity of demand (population and employment) to stops or stations on the network to a great extent explains its greater or lesser usage by potential users. Coverage of service areas can be delineated by GIS through the creation of buffers around transit facilities based on Euclidean (straight-line) distance. A second method is based on calculations of distances along a street network (network distance). The choice of the distance calculation method affects significantly the final results in terms of population covered. This paper assesses the overestimation of the straight-line-distance method, which is the most widely used in coverage analysis, by comparing it with that of network distances. It investigates systematically the factors influencing this overestimation, such as the density of stops or stations, the coverage distance thresholds and the characteristics of the area analysed (street-network design, barriers, and population distribution in the neighbourhood of the bus stop or station). Finally, it concludes that the network-distance method provides systematically better estimates of transit ridership than the Euclidean distance method.

Recognition of the value of landscapes, environmentally, economically, and to quality of life—and, importantly, the embedding of these concepts in legislation such as the European Landscape Convention—has led to the need for an ‘objective’ assessment of these values and the potential impact of changes to them. But studies relating preference information to metric analysis of planimetric viewsheds have so far provided only limited explanation of preference. It has been suggested that this is due to the effect of perspective on the visual topology of the view generating different metrics in perspective from those on the flat map. The completion of the Pan European Study under the EU Framework 5 Visulands project provided a large sample of preference responses to a limited number of computer-generated simple landscape scenarios. As such this is an ideal opportunity to test the significance of perspective on metric correlation with preference. This paper considers the degree to which metrics are altered by a panoramic or viewshed analysis, and the significance of this for any correlation with the preference scores. The implications for the role of the respective media in planning are considered, including that of 3D visualisation as a means for eliciting opinion on landscape preference.

Bayesian belief networks offer an alternative to conventional estimation methods in estimating user preference or utility functions. Because parameter estimates are updated sequentially, this approach seems very promising in user-centred design and data collection systems. The application of such networks however poses several questions, related to speed of learning, sample heterogeneity and discretionalisation of the parameter space. This paper reports the results of a series of numerical simulations which were conducted to gain more insights into these operational decisions.

Construction initiation (CI) of floor area is an important socioeconomic and physical characteristic of urban structure and its evolution. Despite its importance and the availability of CI data, it has not attracted significant attention until now. Since the 1970s, the Tel Aviv-Yafo Municipality and Israel Central Bureau of Statistics have collected annual CI data pertaining to residential and nonresidential categories for subquarters. This paper presents an analysis of the spatial evolution of the city of Tel Aviv in the years 1976–2003, from the CI perspective. Novel aspects of this research are related to autocorrelation analysis CI patterns in individual years versus annually accumulated construction and in core versus noncore build up categories. It is shown that floor-area additions form relatively complex spatiotemporal patterns that are not referred to explicitly in existing urban studies of Tel Aviv. Autocorrelation results suggest the superimposition of current almost homogeneous or random spread over earlier phases of core area domination: the formation of uniform choice space. These random patterns represent primarily spontaneous residential regeneration processes since 1990, and major diffusion of the commercial and public activities beyond the central business district areas.

Public health initiatives have made important but relatively modest gains through individual-level and nonecological health-promotion efforts aimed at increasing physical activity. The previously overlooked built environment is now being considered as facilitating or hindering one's ability to be active. The multiuse greenway is an example of a facility that can support physical activity, but its level of use may be influenced by the accessibility characteristics of the areas surrounding the greenway. In this study, an unobtrusive methodology using GPS and GIS technology was employed to test whether two variables used to measure accessibility, proximity (population density) and opportunities (land-use mixture), predicted the use of greenway segments. The results presented here allow us to confirm that smaller walking and bicycling scales of analysis are better predictors of physical-activity behavior. The results also suggest that solely bringing environmental support for physical activity closer to concentrated areas of population does not necessarily equate to more use. It is important that areas with increased population density have correspondingly increased levels of land-use mixture if increasing physical activity is the goal.