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Journal ArticleDOI

Integrating people and place: A density-based measure for assessing accessibility to opportunities

28 Jul 2014-Journal of Transport and Land Use (Journal of Transport and Land Use)-Vol. 7, Iss: 2, pp 23-40
TL;DR: The goal here is to understand the magnitude and nature of the opportunities a mobile object had access to, given known location points and a time budget for its movement.
Abstract: Mobile object analysis is a well-studied area of transportation and geographic information science (GIScience). Mobile objects may include people, animals, or vehicles. Time geography remains a key theoretical framework for understanding mobile objects' movement possibilities. Recent efforts have sought to develop probabilistic methods of time geography by exploring questions of data uncertainty, spatial representation, and other limitations of classical approaches. Along these lines, work has blended time geography and kernel density estimation in order to delineate the probable locations of mobile objects in both continuous and discrete network space. This suite of techniques is known as time geographic density estimation (TGDE). The present paper explores a new direction for TGDE, namely the creation of a density-based accessibility measure for assessing mobile objects' potential for interacting with opportunity locations. As accessibility measures have also garnered widespread attention in the literature, the goal here is to understand the magnitude and nature of the opportunities a mobile object had access to, given known location points and a time budget for its movement. New accessibility measures are formulated and demonstrated with synthetic trip diary data. The implications of the new measures are discussed in the context of people-based vs. placed-based accessibility analyses.

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Citations
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Journal ArticleDOI
TL;DR: In this article, a cumulative transit-based job accessibility measure is applied and multiple data sources are used, including the transit travel-time data from a Chinese web mapping service and the population and employment distribution data from the 2010 Population Census and the 2013 Economic Census of Beijing.
Abstract: This paper documents inequitable transit-based accessibility to sectoral jobs among population groups with different educational attainment and hukou status in Beijing, China. A cumulative transit-based job accessibility measure is applied and multiple data sources are used, including the transit travel-time data from a Chinese web mapping service and the population and employment distribution data from the 2010 Population Census and the 2013 Economic Census of Beijing. We find clear differences in transit-based job accessibility among employment sectors and among population groups in Beijing. On average, jobs in the finance sector are the most accessible by transit, and jobs in the manufacturing sector are the least accessible by transit. Despite having the highest transit dependency, the low-educated migrant population has the lowest transit-based job accessibility regardless of employment sectors. The disparities are especially large when tying specific populations with specific sectors. Within 60 minutes, the low-educated migrant population using transit, on average, can only access 4.6% of total manufacturing jobs in Beijing. In contrast, the same measure for the highly educated local population accessing jobs in the finance sector is as high as 48.3%. The findings suggest that general transit improvements and jobs and population redistribution efforts, without specific sectoral and population considerations, are unlikely to create equal access to job opportunities. In Beijing, greater attention must be paid to connect the low-educated migrant population to low-skilled and decentralized jobs in the manufacturing, construction, and transportation and storage sectors.

6 citations

Journal ArticleDOI
TL;DR: The analysis of research results in the field of mass transit reveals an explicit similarity between TLD in different cities and the gamma distribution, which points to general regularities in various systems of mass Transit that lead to the similarity in TLD.
Abstract: Modern approaches to the modeling of transport demand imply the use of calibration procedures during the origin-destination (O-D) matrix estimation or transit assignment. These procedures lead to misrepresenting generated and attracted trips or changing the trip length distribution (TLD). It means that the methods of transport planning can be improved by means of determination, validation and implementation of the TLD to calculate the O-D matrix. The analysis of research results in the field of mass transit reveals an explicit similarity between TLD in different cities and the gamma distribution. It points to general regularities in various systems of mass transit that lead to the similarity in TLD. The regularities are determined by studying the spatial distribution of mass transit stops, which are considered trip origins and destinations. The experimental research was conducted in 10 Ukrainian cities using probability theory methods.

6 citations


Cites background from "Integrating people and place: A den..."

  • ...This tendency is partly determined by the increase in the opportunities to achieve a travel purpose in the city center (Horner & Downs, 2014)....

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01 Jan 2018
TL;DR: A large number of the questioned people believe that the current system should be upgraded to facilitate more efficient and effective measurement of climate change-related disasters.
Abstract: ...................................................................................................................................................... 12 Executive Summary .................................................................................................................................... 13 Background ............................................................................................................................................. 13 Objective ................................................................................................................................................. 14 Methods .................................................................................................................................................. 14 Results and Conclusions ......................................................................................................................... 15 Chapter

5 citations

Journal ArticleDOI
TL;DR: By using semi-Markovian and Brownian Bridge stochastic processes, this article offers a probabilistic time-dependent accessibility model that blends the magnitude of opportunities magnitude with the probability of individuals visiting.
Abstract: Accessibility is a fundamental notion in urban planning and its related fields. While accessibility is dynamic and varies during different time moments, most of the accessibility metrics are static and do not take this variation into account. In doing so, to address the questions of (1) how accessible urban opportunities are in different time moments and (2) how accessibility value of a person to a certain place changes regarding his/her spatiotemporal restrictions in time instants, this article—by using semi-Markovian and Brownian Bridge stochastic processes—offers a probabilistic time-dependent accessibility model that blends the magnitude of opportunities magnitude with the probability of individuals visiting. To show the model’s applicability, it was applied on a hypothetical case, along with two common accessibility metrics, and the outputs were compared. Then the proposed model was implemented in a study area for measuring temporal accessibility in two real policies made for daily markets in Isfahan, Iran. The first policy that presented the model application for analytical purposes was “market exclusion and area expansion,” and the second policy that depicted the model implementation for normative usage was “new market location.” Results of the model execution on the hypothetical cases indicated there was a significant difference between the outputs of the common metrics and the ones of the proposed model. In addition, in the study area, the first policy generated higher total accessibility value in comparison with the second policy when market 2 was excluded and the area for market 8 was doubled.

4 citations


Cites background or methods from "Integrating people and place: A den..."

  • ...…in the proposed model, it was attempted to connect people- and place-based measures together because despite the necessity of working in this area (Horner & Downs, 2014), scant studies throughout the literature have been dedicated to develop blended models (Miller & Wu, 2000; Neutens,…...

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  • ...However, despite the necessity of more investigations in this scope of research (Horner & Downs, 2014), a dynamic probabilistic accessibility model incorporating movement principles along with characteristics of urban opportunities has not yet been elaborated and applied in practice....

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  • ...Considering the literature on accessibility modeling and time geography, this paper has fostered an accessibility measure using the frameworks of Horner and Downs (2014) and Song et al. (2016)....

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  • ...By iterating the calculation of STP for a number of individuals, their choice set and movement pattern can be tracked (Horner & Downs, 2014)....

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  • ...Based on the perspective of statistical time geography, Horner and Downs (2014) enlisted network-based TGDE developed by Downs and Horner (2012) and applied it to identify links with more traversing probability and combined the attending probability with the opportunities attractiveness located…...

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Journal ArticleDOI
TL;DR: This study formulated logsum-type space-time accessibility measures that have theoretical and practical advantages over existing STAMs that satisfy the axioms of AM and demonstrate how the proposed STAMS can be used in practice, with an emphasis on parameter estimation.
Abstract: The ease of access to sites for activities is referred to as ‘accessibility,’ and the degree of accessibility is inherently the outcome of land use patterns and transportation networks. The...

4 citations

References
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BookDOI
01 Jan 1986
TL;DR: The Kernel Method for Multivariate Data: Three Important Methods and Density Estimation in Action.
Abstract: Introduction. Survey of Existing Methods. The Kernel Method for Univariate Data. The Kernel Method for Multivariate Data. Three Important Methods. Density Estimation in Action.

15,499 citations

Journal ArticleDOI

5,674 citations


"Integrating people and place: A den..." refers background in this paper

  • ...Note that this does not express the raw probability of finding the object at a location; rather it provides a relative measure of that likelihood, which that can be directly compared across all locations in the map (Silverman 1986)....

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Journal ArticleDOI
01 Jan 1970

3,730 citations

Journal ArticleDOI
TL;DR: In this article, an empirical analysis of the residential development patterns illustrates that accessibility and the availability of vacant developable land can be used as the basis of a residential land use model.
Abstract: An empirical examination of the residential development patterns illustrates that accessibility and the availability of vacant developable land can be used as the basis of a residential land use model. The author presents an operational definition and suggests a method for determining accessibility patterns within metropolitan areas. This is a process of distributing forecasted metropolitan population to small areas within the metropolitan region. Although the model presented is not yet sufficiently well refined for estimating purposes, the concept and the approach may be potentially useful tools for metropolitan planning purposes.

2,954 citations


"Integrating people and place: A den..." refers background in this paper

  • ...…approaches (Levine et al. 2012; Neutens, Schwanen, and Witlox 2011; Li et al. 2011; Harris 2001; Miller 1999; Burns 1979; Weibull 1976; Ingram 1971; Hansen 1959; Shen 1998)While precise definitions vary across disciplines and analytical contexts, generally accessibility is thought to mean the ease…...

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  • ...Accessibility-related research has thrived during the last few decades, with new data and computational tools facilitating innovations rooted in classical approaches (Levine et al. 2012; Neutens, Schwanen, and Witlox 2011; Li et al. 2011; Harris 2001; Miller 1999; Burns 1979; Weibull 1976; Ingram 1971; Hansen 1959; Shen 1998)While precise definitions vary across disciplines and analytical contexts, generally accessibility is thought to mean the ease with which activities can be reached in space....

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Journal ArticleDOI
TL;DR: In this article, the authors provide a framework for the development of accessibility measures and two case studies suggestive of the range of possible approaches are presented, as well as issues that planners must address in developing an accessibility measure.
Abstract: Accessibility is an important characteristic of metropolitan areas and is often reflected in transportation and land-use planning goals. But the concept of accessibility has rarely been translated into performance measures by which policies are evaluated, despite a substantial literature on the concept. This paper is an attempt to bridge the gap between the academic literature and the practical application of such measures and provide a framework for the development of accessibility measures. Issues that planners must address in developing an accessibility measure are outlined, and two case studies suggestive of the range of possible approaches are presented.

1,437 citations