Ayse Ozbil

Bio: Ayse Ozbil is an academic researcher from Northumbria University. The author has contributed to research in topics: Street network & Poison control. The author has an hindex of 6, co-authored 10 publications receiving 205 citations. Previous affiliations of Ayse Ozbil include Okan University & Georgia Institute of Technology.

Understanding the link between street connectivity, land use and pedestrian flows

Abstract: The distribution of pedestrian movement by street segment in three areas in Atlanta is modeled in relation to measures of street connectivity and land use. Although land use accounts for the pronounced differences in average pedestrian volumes per area, the connectivity of the street network affects the distribution of pedestrians on a street-by-street basis within each of them. The measures of connectivity that are used describe the density of street connections and the extent to which streets are sinuous or aligned. This study enhances previous findings, particularly those using space syntax, by better controlling for the effects of land use as compared to the effects of street connectivity and network layout. Asserting the independent role of street network design is important given that streets act as the long-term framework within which land uses change over time. The measures of street connectivity are easy to implement on a GIS platform to support the evaluation and development of designs and regulatory frameworks that promote walking, whether it be in the interest of public health, in reducing automobile dependence or in supporting vibrant urban communities.

Comparative Associations of Street Network Design, Streetscape Attributes and Land-Use Characteristics on Pedestrian Flows in Peripheral Neighbourhoods

Abstract: Research has sufficiently documented the built environment correlates of walking. However, evidence is limited in investigating the comparative associations of micro- (streetscape features) and macro-level (street network design and land-use) environmental measures with pedestrian movement. This study explores the relative association of street-level design-local qualities of street environment-, street network configuration –spatial structure of the urban grid- and land-use patterns with the distribution of pedestrian flows in peripheral neighbourhoods. Street design attributes and ground-floor land-uses are obtained through field surveys while street network configuration is evaluated through space syntax measures. The statistical models indicate that the overall spatial configuration of street network proves to be a stronger correlate of walking than local street-level attributes while only average sidewalk width appears to be a significant correlate of walking among the streetscape measures. However, the most significant and consistent correlate of the distribution of flows is the number of recreational uses at the segment-level. This study contributes to the literature by offering insights into the comparative roles of urban design qualities of the street environment and street network layout on pedestrian movement. The findings also offer evidence-based strategies to inform specific urban design and urban master planning decisions (i.e., the provision of more generous sidewalks on streets with relatively higher directional accessibility) in creating lively, walkable environments.

Modeling street connectivity and pedestrian movement according to standard gis street network representations 018

Abstract: We study three 1 mile x 1 mile areas in Atlanta to establish correlations between street configuration and densities of pedestrian movement. Two kinds of analysis are used: first, standard syntactic analysis applied to axial maps drawn to cover surrounding areas large enough so that Radius 3 Integration values assigned to observation spaces suffer no edge effects; second, new techniques of analysis that can be applied to standard GIS representations of street center-lines. It is shown that the new measures post-dict movement densities as well as the standard syntactic measures.

The Effects of Street Configuration on Transit Ridership

Abstract: This study examines the impact of street network connectivity on transit patronage. The aim is to better understand how connectivity affects the decision to use public transportation after we control for population density and the effect of walking distance from the transit station. Data on population densities, transit service features, and annual average daily station boardings are drawn from Chicago (CTA), Dallas (DART), and Atlanta (MARTA). Results suggest that metric reach, which measures the street length that is accessible within a walking range, has significant impact on ridership levels jointly with population density and two attributes of transit service features. In particular, the estimates indicate that metric reach is a stronger predictor of transit use than station area population densities.

What is a Walkable Place? The Walkability Debate in Urban Design

Abstract: What exactly is meant by the term ‘walkability’? In professional, research and public debates the term is used to refer to several quite different kinds of phenomena. Some discussions focus on environmental features or means of making walkable environments, including areas being traversable, compact, physically enticing and safe. Others deal with outcomes potentially fostered by such environments, such as making places lively, enhancing sustainable transportation options and inducing exercise. Finally some use the term walkability as a proxy for better design whether composed of multiple, measurable dimensions or providing a holistic solution to urban problems. This review both problematizes the idea of walkability and proposes a conceptual framework distinguishing these definitions. This matters for urban design, because what is considered a walkable place varies substantially between definitions leading to substantially different designs. By mapping the range of definitions, this review highlights potential conflicts been forms of walkability.

Urban network analysis. A new toolbox for ArcGIS

Abstract: This paper introduces an open-source Urban Network Analysis (UNA) toolbox for ArcGIS. The toolbox can be used to compute five types of network centrality measures on spatial networks: Reach; Gravity Index; Betweenness; Closeness; and Straightness. Though primarily developed for the analysis of urban streetand building-networks, the tools are equally suited for other spatial networks, such as railway networks, highway networks, or utility networks. Unlike previous network centrality tools that operate with two network elements (nodes and edges), the UNA tools include a third network element – buildings – that can be used as the spatial units of analysis for all measures. Two neighboring buildings on the same street segment can therefore obtain different accessibility results. The UNA tools also allow buildings to be weighted according to their particular characteristics – more voluminous, more populated, or otherwise more important buildings can be specified to have a proportionately stronger effect on the analysis outcomes, yielding more accurate and reliable results to any of the specified measures. The toolbox is built for easy scaling – it can operate on small-scale and detailed networks of dense urban areas, as well as large-scale regional networks. The toolbox requires ArcGIS 10 software with an ArcGIS Network Analyst Extension. RÉSUMÉ. Cet article présente l’utilitaire open source « Analyse d’un réseau urbain », ou UNA (Urban Network Analysis), pour ArcGIS. L’utilitaire permet de calculer cinq types de mesures de centralité sur des réseaux spatiaux : Reach, Gravity Index, Intermédiarité, Proximité et Straightness. Bien qu’ils aient été développés avant tout pour analyser des réseaux de rues ou de bâtiments en contexte urbain, les outils sont adaptés également à l’étude d’autres réseaux spatiaux, comme des réseaux ferroviaires, autoroutiers ou de services. À la différence des utilitaires de calcul de centralité existant précédemment, qui prenaient en compte deux éléments du réseau (les nœuds et les arêtes), les outils UNA intègrent un troisième type d’éléments – les bâtiments – qui peuvent être utilisés comme unités d’analyse spatiale pour toutes les mesures. Les outils UNA permettent aussi de 288 RIG. Volume 22 – n° 2/2012 pondérer les bâtiments en fonction de leurs caractéristiques particulières : les bâtiments plus gros, plus peuplés, ou plus importants pour quelque autre raison, peuvent être spécifiés et avoir un effet proportionnellement plus important sur les résultats de l’analyse, ce qui permet d’obtenir des résultats plus précis et plus fiables pour chacune des mesures opérées. L’utilitaire permet des changements d’échelle faciles : il peut être appliqué à des réseaux à petite échelle et haut niveau de détail dans les zones urbaines denses aussi bien qu’à des réseaux régionaux à grande échelle. L’utilitaire nécessite le logiciel ArcGIS 10 avec une extension pour l’analyse des réseaux (ArcGIS Network Analyst Extension).

How do local actions affect VMT? A critical review of the empirical evidence

Abstract: For environmental, economic, and social reasons, reducing vehicle miles traveled (VMT) has become a goal of transportation and land use planners in communities around the world. There are many policy ideas for how to reduce VMT. However, information about how effective each of these actions might be in a particular context is not generally available. In this paper, the authors summarize and critique the best evidence from the literature on how much various factors affect VMT. The authors look at a broad range of factors, including land use characteristics such as residential density and land use mix, as well as specific transport policies and programs such as transit improvements, road pricing, and programs aimed specifically at changing people’s travel choices. Overall, it is clear from the literature that local-level policymakers can take actions that are likely to reduce VMT. However, gaps in the knowledge base remain, and often the results that are in this literature are presented in a way that is not useful for real-world decision making. In addition to summarizing findings from the existing literature, the authors provide an assessment of the gaps in the evidence base, and detailed suggestions for making future research in this area most useful to policymakers who aim to reduce VMT.