Accessibility,equity and health care: review and research directions for transport geographers

Research at the confluence of accessibility, equity and health is flourishing. And yet, there is only slow and modest progress in terms of improving the spatial and temporal accuracy of measuring accessibility and equity of accessibility to health care services. This paper critically reviews the latest methodological and empirical research developments and trends in this area through a transport geography lens. More specifically, this paper discusses recent accomplishments in terms of modeling accessibility and provides a systematic and comprehensive literature review of their application in empirical studies of health care delivery. Based on this literature review a research agenda is put forward, identifying knowledge gaps that transport researchers can help to fill. These knowledge gaps pertain to the need for more spatially disaggregated, individualized and temporally-aware accessibility metrics, more sophisticated geocomputational tools to operationalize such metrics and improved measurement of equity considerations in empirical research.     

Accessibility measurements in São Paulo,Rio de Janeiro,Curitiba and Recife,Brazil

Increasing attention is given to public transport services in cities of the Global South as a tool to enhance social inclusion and support economic development. Against this background, developing and evaluating indicators that quantify the distribution of public transport services from a social equity perspective is essential. The aim of the study is, therefore, to assess the equity of public transport services in four metropolitan regions in Brazil (São Paulo, Rio de Janeiro, Curitiba and Recife) with two commonly used indicators of public transport provision. The first indicator measures proximity to rapid transit infrastructure (bus rapid transit, light rail and heavy rail stops with high frequency throughout the day), and the second measures accessibility to jobs by public transport. While simple indicators of proximity to public transport stops are most commonly used given their ease of operationalization and communication, accessibility to job indicators are more representative of the benefits provided to individuals by the public transport network. Combining these two indicators in one study provides a quantitative assessment of the socio-spatial distribution of public transport services in four large metropolitan areas in Brazil and the results demonstrate that lower-income households are disadvantaged in terms of public transport services in all four metropolitan areas. Furthermore, the results highlight the importance of quantifying accessibility by public transport, in addition to proximity to rapid transit, and thereby sheds light on the importance of developing openly available public transport schedules and geographic data. This study is of relevance to planners and researchers wishing to measure and evaluate public transport equity in the Global South.     

Accessibility modelling: predicting the impact of planned transport infrastructure on accessibility patterns in Edinburgh,UK

The achievement of good spatial accessibility and equity in the distribution of urban services is one of the supreme goals for urban planners. With Scottish Government backing, the City of Edinburgh Council (CEC) has started to construct a tram network to cater for the future needs of Scotland’s capital city by providing an integrated transport solution using trams and buses. Spatial Network Analysis of Public Transport Accessibility (SNAPTA) which is a GIS-based accessibility model has been developed to measure the accessibility by public transport to different urban services and activities. The model responds to several limitations in other existing accessibility models in planning practice. It offers an alternative and practical tool to help planners and decision makers in examining the strengths and weaknesses of land use – transport integration. SNAPTA has been applied to a pilot study in Edinburgh city to identify the contribution of the infrastructure improvements of the tram system and Edinburgh South Suburban Railway (ESSR) to improved accessibility by public transport to six types of activity opportunities. This paper outlines the concept and methodology of the SNAPTA model, and presents the findings related to this pilot study with a focus on changes in potential accessibility to jobs between four different public transport network scenarios. The accessibility values so obtained help to identify the gaps in the coverage of the public transport network and the efficiency in the spatial distribution of urban services and activities. The findings focus on whether the planned transport infrastructures for Edinburgh will lead to better accessibility and reduced inequity (in terms of accessibility) across the city.     

Assessing equity in transport accessibility to work and study: The Bogotá region

This research was aimed at exploring levels of equity in accessibility to employment and education in the city-region of Bogotá, Colombia's capital city. Building on consolidated methodologies for the assessment of potential accessibility, we estimate accessibility indicators at the zone level, evaluate how potential accessibility varies among income groups, and present evidence related to transport mode, in order to analyze social and spatial inequalities produced by the distribution of accessibility to employment and education activities. The research incorporates a method to evaluate how accessibility varies among zones according to average income and mode of transport in order to produce evidence-based arguments that can inform transport policy in the city-region of Bogotá, and other similar contexts in the Global South. Our results show strong distributional effects of the socio-spatial and economic structure of the city-region, its transport infrastructure and services, and the effect of current transport and land-use policies for citizens of different income groups. The tools and empirical evidence in this research seek to contribute to informed policy development in Latin America and other developing contexts, and feeding current debates on the role of accessibility in addressing social and spatial inequalities stemming from urban mobility.     

Exploring public transport equity between separate disadvantaged cohorts: a case study in Perth,Australia

This paper explores the equity distribution of public transport for three separate disadvantaged cohorts including elderly residents, low-income households and no-car households for Perth, Western Australia. It also undertakes a city-wide equity analysis of Perth and compares this with a published analysis for Melbourne. Overall the public transport distribution of the three socially disadvantaged groups was identified to be less equitable when compared to the population as a whole. The elderly had the most inequitable distribution of population relative to other cohorts. Perth’s population exhibits a 0.52 Gini coefficient suggesting a relatively unequal spatial distribution of services to the population. However, this is much better than Melbourne (at 0.68). Results imply that 70% of Perth’s population have only 33% of services supplied, whilst in Melbourne this figure was 19%. Policy implications and areas for future research in this field were identified.     

Accessible accessibility research challenges

Accessibility is a key concept in the field of transport geography. There is a rich, though not very mature, body of literature on this topic which is largely application-driven. The focus in the literature is generally on methods and concept and/or on applications. Applications generally focus on ex ante or ex post evaluations of the implications for accessibility of (candidate) policy plans. An important question is which are the main challenges in the area of accessibility research? This paper aims to examine this question and provide a research agenda for the coming one or two decades or so. The focus is on putting relatively new topics on the agenda, rather than making suggestions for improvements of given accessibility indicators. The paper does not aim to provide a complete list, but rather proposes avenues for future research focusing on (1) indicators to express accessibility, and (2) evaluation. In the area of indicators the challenges include the impact of ICT on accessibility; the inclusion of the robustness of the transport system in indicators; comparing perceptions of accessibility and traditional accessibility indicators; the option value; and the indicators of accessibility for goods transport, air transport, and slow modes. In the area of evaluation the paper discusses the pros and cons of the logsum as an accessibility measure, ethical aspects, comparisons of accessibility indicators to evaluate a specific case, and the needs of the clients of accessibility research.     

Prioritizing low-stress and equitable bicycle networks using neighborhood-based accessibility measures

As cities across the United States strive to create comfortable bicycle networks for mainstream users, three topics have garnered attention: project prioritization criteria, accessibility to everyday destinations, and social equity. However, these topics have not often been integrated in research or practice. This paper introduces a method to assess the extent to which reductions in “Bicycle Level of Traffic Stress” (LTS) on segments of a citywide bicycle network increase accessibility to supermarkets, pharmacies, banks, and public libraries. Six accessibility performance measures are developed and evaluated for 278 neighborhoods in Baltimore, Maryland using a GIS-based approach. The demographic distributions of accessibility results are further analyzed, focusing on disadvantaged populations. Using a set of 106 proposed bicycle projects, the marginal accessibility gains and cumulative demographic impact across affected neighborhoods are assessed for each project. These results are ranked and crosslisted to identify a set of projects that balance accessibility gains with equity objectives. The prioritization results demonstrate some overlap with the short-term priorities embodied in City of Baltimore's 2015 Bike Master Plan, but they also highlight projects in other areas, specifically those that would serve neighborhoods most disadvantaged in terms of racial segregation, high poverty rates, and low rates of vehicle ownership.     

Improving Bus Service Levels and social equity through bus frequency modelling

Bus lines play an essential role in providing urban public transport service. Demographic and socioeconomic characteristics determine the specific transport service needs of districts that, in most cases, are not served by the existing bus routes. Small changes in the frequency of a bus route can have a direct effect on the territorial distribution of a city's public transport service. Adjusting the frequencies of a bus fleet can help planners improve the service level and adapt the fleet's spatial distribution. A bus frequency optimization methodology is proposed to improve harmonization between service level and social equity in public transport. The method relies on a simple spreadsheet that integrates geographic data about bus routes and socioeconomic information about city districts. Simulation and optimization procedures are coordinated to appropriately adjust the routes to the geographic space. The proposed method is tested in a real case study that demonstrates its usefulness in analysing the service level and equity of a transport system and improving a city's public transport planning.     

Measuring the accessibility and spatial equity of urban services under competition using the cumulative opportunities measure

As accessibility becomes an increasingly relevant concept in the analysis of sustainable transport and urban development, the accuracy of accessibility measures becomes increasingly vital. While more complex measures are gradually gaining popularity with increasing data and computational resources, policy makers and planners are still prone to opt for less complex methods that are easy to use and interpret. The cumulative opportunities measure is the most widely applied accessibility measure in planning practice, but it is also among the least accurate due to its lack of consideration of the impact of competition for those opportunities. This study seeks to highlight the impact of addressing competition for different urban services in the cumulative opportunities measure. A competition component is added to the measure, which is applied to a case study of three types of urban services in the Perth metropolitan area; jobs, primary/secondary education and shopping. The results show that considering competition changes the spatial patterns of accessibility and its equity. Since this approach reveals demand-supply imbalances, it can more accurately determine spatial inequalities in accessibility, and hence increases the utility of the cumulative opportunities measure. We also find that the three services had varying levels and spatial patterns of accessibility and spatial equity, thus relying on any single one of them for assessing spatial structural performance can be misleading.     

Determining intra-urban spatial accessibility disparities in multimodal public transport networks

Urban rail systems have been added to public transport systems, thereby changing distribution disparities in urban spatial accessibility. These disparities reflect both the ability of the public transport system to meet the needs of residents and the locational pros and cons of public service facilities. In this paper, integrated accessibility metrics are used to assess the disparities in Nanjing, Jiangsu Province, China. This is achieved by dividing the urban space into a multilevel grid that can be easily combined with grid-based population data to facilitate accessibility modeling, calculation, and evaluation. Additionally, an acquisition method for more accurate travel time data in the multimodal public transportation network was developed on the basis of an Internet mapping service. This provides a realistic, multimodal, door-to-door modeling approach that avoids the requirement of building complex traffic networks through Geographic Information System (GIS) software and simplifies road network modeling efforts. The results show that this modeling method can be used to reflect the accessibility disparities in the Nanjing urban space objectively and accurately.     

Are we keeping up? Accessibility,equity and air quality in regional planning

Many US metropolitan areas have undergone dramatic shifts in socioeconomic organization.. As urban areas gentrify, many low-income residents and communities of color have transitioned towards the exurban periphery. These suburban neighborhoods tend to have fewer employment opportunities and are fairly disconnected from public transportation networks serving the urban core. Using regional transportation plans (RTPs) for three California MPOs, we show that the transportation accessibility and environmental health issues affecting these exurban communities are unique and inadequately captured by the MPOs' current equity metrics. MPOs performance evaluation is regional and achieving equity within the urban core communities will not address emerging equity, accessibility and air quality concerns for exurban communities. With a brief history and a focused case study of RTPs for the San Francisco Bay Area, San Diego, and Fresno, we examine how air pollution, equity, and transportation interact in three different types of 21st century cities. We find that when allocating limited transportation funds, California metropolitan planning organizations (MPOs) prioritize the improvement of existing public transportation in urban core areas over expansion of transit networks towards disconnected exurbs. This approach is an effective way to reduce vehicle miles traveled (and thus, air pollution) at the regional level due to high population concentrations in urban cores. However, this approach also concentrates the air quality benefits of VMT reduction in these same urban core areas. Exurban residents' on-road and near-road exposure to Traffic-Related Air Pollution (TRAP) will not be reduced by improving public transit within the urban core. We argue that although these suburban and exurban communities are a small percentage of the regional population, they have a right to share in the benefits of transportation investments, particularly given the historical and ongoing patterns of displacement and economic exclusion from urban core areas.     

Fair accessibility – Operationalizing the distributional effects of policy interventions

A fair distribution of public transport benefits is a commonly stated goal of agencies and operators of public transport. However, it is less complicated and costly to provide accessibility in some parts of cities and their surroundings than in other parts. Densely populated areas, and areas situated closer to the city center therefore often have higher public transport accessibility than remote or sparsely populated areas. Neglecting these realities results with an unrealistic assessment of equity in service provision and hampers their consideration when setting policy goals. In this study, we propose a framework for investigating equity in the distribution of accessibility, where the suggested goal is to provide residents with equal accessibility for equally dense and central areas. For the Stockholm County, we show that accessibility may seem to be distributed horizontally inequitable and vertically regressive. However, once controlling for how dense and close to the city center residents live, while still being horizontally inequitable the distribution of accessibility in Stockholm County is found progressive, i.e., benefiting those with lower incomes. We demonstrate the proposed method for the case of skip-stop train operations and find that it shifts our constructed accessibility measure toward a more horizontally inequitable and vertically progressive state. We conclude that our proposed method can be a potent way for public transport agencies to measure and concretize equity goals and evaluate policy changes.     

History of thought and prospects for road pricing

Policy implications of the research program presented in this issue of Transport Policy are discussed according to their theoretical, historical and political origins. Problems related to government taxation are analysed in the light of the early literature on transport externalities pricing that began with Pigou [Pigou, A.C., 1920. The Economics of Welfare. MacMillan, London. (References are usually made to the 1932, 4th ed.)]. We then discuss decision-making processes in transport pricing implementation involving redistribution issues, acceptability, user's satisfaction and equity. The article also briefly reviews the general agenda of EU transport policy     

Towards inclusive transport landscapes: Re-visualising a Bicycle Sharing Scheme in Santiago Metropolitan Region

Bicycle Sharing Schemes (BSS) are re-emerging as promising components of urban mobility solutions worldwide. However, the lack of consistent collaboration strategies between different actors and institutions, which have been tested in a wide range of cities and contexts regarding their design, tender, operation and expansion, raises significant social and governance implications. Urban transport features as a melting pot for diverse policy objectives, ranging from business model innovation, public tendering, and accessibility increase to the equity and social justice agenda.By employing a Multi-Level Perspective (MLP) framework and by introducing alluvial diagrams and circular dendrograms to BSS planning through a mixed-methods approach, this article illustrates an innovative tool in managing BSS in the context of the Global South. The strength of such diagrams has been underestimated to date since they can be particularly useful for public and private urban transport planners and policy-makers. Visualising user flows in such a manner, particularly in near-live time, may offer valuable insight on the operational challenges of BSS. Findings of the cross-sectional survey in Santiago de Chile confirm that maintenance is significant for user satisfaction levels. Furthermore, decisions regarding BSS expansion and modification could be based on such analysis and diagrams due to the precise identification of both the busiest and those under-represented BSS stations based on revealed preferences.     

Assessing equity in park accessibility using a travel behavior-based G2SFCA method in Nanjing,China

Spatial equity of parks is a major concern in environmental justice studies. While many measurements have been used to evaluate access to parks, few studies have considered the impact of travel behavior on park accessibility. This study aims to establish a travel behavior-based Gaussian two-step floating catchment area (TB-G2SFCA) method to assess spatial equity of parks in the Nanjing region, and Local Moran's I index is applied to identify spatial agglomeration patterns in assessing equity. The results demonstrate that (1) the traditional single-mode model maybe cannot provide accurate approach to evaluating park accessibility while the TB-G2SFCA method can provide a more realistic park accessibility evaluation; (2) the inhabitants of most communities distributed south of the Yangtze River can obtain better park services than the northern areas; (3) the spatial disparities of equity in park accessibility are severe in three suburban districts, relatively minor in four central districts, and insignificant in two central districts. These findings may assist urban planners and policy makers to frame more reasonable policy and planning to improve spatial equity to parks in urban areas.     

Planning for low carbon mobility: Impacts of transport interventions and location on carbon-based accessibility

Accessibility has been conceptualized and applied in different ways, depending on the underlying political objectives. In the context of climate change and ambitious emission reduction targets, environmental concerns have risen high on the political agenda. Existing methods for assessing transport-related environmental impacts typically depend on realized or modeled travel behavior. Many of them do not entail a spatial dimension, ignore the importance of the land use component, lack scenario building capabilities or have limited communication value. Consequently, accessibility analysis and planning could make a valuable contribution towards a low carbon transition, but needs to attune to the specific objective of reducing transport-related greenhouse gas emissions. This paper introduces a novel conceptualization of location-based accessibility, where CO₂ emissions are used as a travel cost in place of time or monetary costs. By identifying and assessing options for interventions in the land use and transport system, carbon-based accessibility instruments might serve a number of potential decision-making purposes related to low carbon mobility planning. Carbon-based accessibility of a business park in the Munich region is analyzed in multiple scenarios to demonstrate the application potential of the method. The experiential application focuses on the effects of changes in vehicle efficiency and occupancy rates of both car and transit, but also compares the resulting carbon-based accessibility levels to alternative sites with the transport system unchanged. Applying carbon-based accessibility instruments to real-world planning issues could enhance strategic decision-making processes in the context of climate change mitigation.     

“I am like a deaf,dumb and blind person”: Mobility and immobility of Chinese (im)migrants in Flushing,Queens, New York City

This paper contributes to research on daily mobility experience of (im)migrants in cities and expands the conceptualizations of mobility by examining intentionality and its relations to locality. Through place-based research on mobility and immobility of Chinese (im)migrants in Flushing, Queens, New York City, this paper explores: 1) mobility patterns of recent (im)migrants in an urban setting; 2) the constraints, resources and their coping strategies for everyday mobility; and 3) the dialectal relationship between voluntary and involuntary immobility, and between mobility and ethnic communities. This study reveals that immobility is not always the result of inaccessibility, but structural barriers in the broader society such as socioeconomic inequality and racial discrimination. Involuntary immobility encourages overdependence on locality. With its high place accessibility, Flushing provides (im)migrants with a plethora of ethnic mobile resources, as well as social networks and community resources. The relative immobility among Chinese (im)migrants in Flushing is compensated by the flows and movements of people, goods and information both at the local and transnational scale. The contrast between insider-ness and outsider-ness further enhances their attachment to the local community and discourages them from moving. Thus, locality mitigates involuntary immobility but paradoxically nurtures voluntary immobility that hinders the transfer of potential mobility to actual mobility, and physical mobility to social mobility. Without considering locality, stillness is easily mistaken for immobility; without considering intentionality, accessibility is easily equated to mobility. Therefore, solutions to transportation equity do not lie solely in transportation accessibility itself, but more broadly in individual capability, immigration policy, labor market equality and community development.     

Future accessibility impacts of transport policy scenarios: Equity and sensitivity to travel time thresholds for Bus Rapid Transit expansion in Rio de Janeiro

The accessibility impacts of transport projects ex-post implementation are generally evaluated using cumulative opportunity measures based on a single travel time threshold. Fewer studies have explored how accessibility appraisal of transport plans can be used to evaluate policy scenarios and their impacts for different social groups or examined whether the results of project appraisals are sensitive to the time threshold of choice. This paper analyzes how different scenarios of full and partial implementation of the TransBrasil BRT project in Rio de Janeiro (Brazil) will likely impact the number of jobs accessible to the population of different income levels. The analysis is conducted under various travel time thresholds of 30, 60, 90 and 120 min to test whether the results are sensitive to the boundary effect of the modifiable temporal unit problem (MTUP). Compared to a partial operation scenario, the full implementation of TransBrasil that extends this corridor into the city center would lead to higher accessibility gains due to network effects of connecting this BRT to other transport modes. Nonetheless, the size of the accessibility impacts of the proposed BRT as well as its distribution across income classes would significantly change depending on the time threshold chosen for the accessibility analysis. Considering cut-off times of 30 or 60 min, both scenarios of TransBrasil would lead to higher accessibility impacts in general and particularly for low-income groups, moving Rio towards a more equitable transportation system. However, under longer thresholds of 90 and 120 min, an evaluation of this project would find much smaller accessibility gains more evenly distributed by income levels. The paper highlights how time threshold choice in cumulative opportunity measures can have important but overlooked implications for policy evaluation and it calls for further research on the MTUP in future transport and mobility studies.     

Transit Deserts: Equity analysis of public transit accessibility

Areas, where disadvantaged and transit-dependent populations are provided with inadequate amounts of transit supply, can be labeled transit deserts. Exploring transit deserts may help transit agencies improve accessibility to services while improving transit distribution and equity. This study utilizes the concepts of transit demand and transit supply to identify transit deserts in the City of Dallas. The comprehensive public transit accessibility (CPTA) score is introduced to evaluate accessibility to transit and to provide a holistic view of transit supply. While previous studies have primarily used proximity or spatial indicators to describe accessibility, this study utilizes a comprehensive set of spatial and temporal measures (connectivity to the network, connectivity to destinations, service frequency, flexibility, and time efficiency) to estimate accessibility to transit. Overlapping areas of high demand (transit dependency) and low supply (as measured using the CPTA) are then characterized as transit deserts. The CPTA score and its application to the analysis of transit deserts provides a universal framework which can be broadly applied by transit agencies, city officials, and transit stakeholders. The contributions of this study are as follows: first, developing a comprehensive framework to estimate transit supply or accessibility; and second, introducing a methodology for identifying transit deserts.     

基于空间成本分配的北京城市轨道交通票价方案选择评价

成本的空间分配是公共交通公平的重要内容,受不同票价方案影响。为了比较不同票价方案下的空间成本分配差异,运用可达性方法,采用北京地铁及其计程票制数据在城市轨道交通站点间票价的基础上计算区域站均票价,分析不同票价方案下北京区县空间成本分布格局差异,给出区县票价方案择优结果,并对2014年北京城市轨道交通票价听证会选择的票价方案进行评价。结果显示,北京各区县并不适合一种票价方案,各区域有最佳的票价方案选择,选择一种票价方案会导致区域间不公平,为城市轨道交通票价调整政策提供一定的参考。