Floating Catchment Area Model Research Articles

How does shared mobility impact metro-based urban commercial travel accessibility and Equity?

The integration of shared mobility services, such as bike-sharing and ride-hailing services, with metro systems enhances the effectiveness and convenience of urban mobility. Various transportation modes significantly impact the accessibility and equity of commercial travel for the purpose of shopping, entertainment, tourism, and catering, due to the diversity of options, destinations, and origins. This study, based on the primary urban regions of Chengdu in 2023, employs the Gaussian two-step floating catchment area model, Gini Index, and Lorenz curve to examine the effects of shared mobility on the accessibility pattern and spatial equity of commercial services. It shows that the bike-sharing-metro travel mode enhances overall commercial accessibility, whereas the ride-hailing-metro travel mode has a substantial impact on accessibility distribution. Additionally, the commercial accessibility distribution pertains to the arrangement of commercial establishments in short-distance travel, whereas it exhibits a central hub and peripheral locations for long-distance travel. While the equity of commercial services improves effectively, metro transportation remains situated at the core of the transportation mode. The creation of the metro transit-oriented development should thoroughly assess the impact of shared mobility on the station area and prioritize the equilibrium between urban commercial and residential sectors.

Measuring and optimizing the spatial accessibility of primary health care in remote and rural areas: a case study of Liannan Yao Autonomous County in China

The need for equitable access to primary healthcare services in the current global context has attracted widespread attention, prompting nations to continuously enhance their grassroots medical service levels. In response, China launched the "Healthy China" initiative, which prioritizes the enhancement of national health as a core goal of the healthcare system and uses this opportunity to deepen reforms aimed at strengthening primary care. However, in remote and rural areas, the optimization of medical resource allocation and the achievement of balanced service development remain critical challenges owing to limited resources. This study selected Liannan Yao Autonomous County, which is situated in the northwestern corner of Guangdong Province, as a case study due to its remote mountainous location, underdeveloped economy, and minority region characteristics. Through field research and interviews, this study thoroughly explored the needs of both supply and demand, factoring in elements such as the service capability of healthcare facilities and residents' travel thresholds to enhance the two-step floating catchment area model, thus making it more applicable to remote villages. By integrating electric bikes and cars, which are the primary means of transportation in rural areas, this study conducted a thorough analysis and comparison of the accessibility of medical services in Liannan Yao Autonomous County (Liannan County) . The results reveal significant disparities in healthcare accessibility, an uneven distribution of medical resources, and varying impacts of transportation conditions and facility service capabilities on accessibility. Notably, the study revealed that improving transportation conditions alone has limited effects in rural areas; the key lies in balancing medical service capabilities and the rationality of overall layouts. From the perspectives of equity and efficiency, this study employs the equitable coverage model and the efficiency-driven model to construct two scenarios, comparing accessibility changes in Liannan County under both conditions and proposing strategies to improve the spatial layout of local healthcare facilities. This research not only deepens the understanding of healthcare service accessibility in rural areas but also provides a scientific basis for optimizing resource allocation and enhancing primary medical services, offering valuable guidance and reference for Liannan County and other similar rural regions.

Research on the Evaluation of an Age-Friendly Layout of Medical Service Facilities in Wuhan City Based on Accessibility

Accessibility is an important indicator for measuring the level of medical facility services in cities. Traditional studies on healthcare accessibility for the elderly have typically focused on the capabilities of emergency services while overlooking the daily independent healthcare needs of the elderly. Taking Wuhan City as an example, the Gaussian two-step floating catchment area method is used in this study to measure the accessibility of urban elderly residents with respect to general hospitals, specialized hospitals, and community health service centers. It also analyzes the appropriateness of the medical facility layout for the elderly in Wuhan City. The research findings indicate the following: (1) The accessibility evaluation method for urban medical facilities established with the Gaussian two-step floating catchment area model can accurately assess the supply–demand relationship between the elderly and various levels of medical facilities. (2) The overall coverage of medical service facilities in Wuhan City is relatively high, but there are significant differences in accessibility for elderly residents in different areas. (3) The appropriateness of daily healthcare access for elderly residents in the central urban areas of Wuhan City is mainly influenced by the layout of general hospitals, while, in the peripheral areas, it is mainly influenced by the layout of specialized hospitals and community health service centers. (4) Improving the appropriateness of urban medical facilities for elderly individuals requires differentiated improvement measures tailored to the characteristics of different zones.

Detecting heterogeneity of spatial accessibility to sports facilities for adolescents at fine scale: A case study in Changsha, China

Abstract It is crucial for social sustainability that adolescents have access to social sports services fairly. However, there are few research studies on requirements for sports facilities and spatial accessibility of adolescents at a fine scale. Further, identifying the heterogeneity of the relationship between spatial accessibility and other factors and their scales simultaneously would be conducive to reveal the variations of spatial accessibility effectively under the potential scale effect. This research aims to explore the heterogeneity of spatial accessibility to sports facilities at a fine scale in Changsha, China. The Gaussian-based two-step floating catchment area model is first employed to evaluate spatial accessibility. Then, multiscale geographically weighted regression (MGWR) is applied to examine the relationship between spatial accessibility and its associated factors. The mean accessibility in Yuelu District (0.158) is the highest as well, and the standard deviation (0.236) is also the highest one. Both the accessibility (0.019) and its standard derivation (0.029) in Furong District are the lowest. The results show that there is a lack of balance of spatial accessibility for the clusters with different accessibility levels distributed in the study area. Some socio-economic factors, such as housing price and nighttime light intensity, have significant impacts on spatial accessibility for adolescents with spatial and scale heterogeneity by using MGWR. Based on heterogeneous distribution and association, suggestions for promoting spatial accessibility to sports facilities for adolescents are proposed.

Accessibility to ERCP-performing hospitals among patients with pancreatic cancer living in SEER regions.

The two most common interventions used to treat painless jaundice from pancreatic cancer are endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous transhepatic biliary drainage (PTBD). Our study aimed to characterize the geographic distribution of ERCP-performing hospitals among patients with pancreatic cancer in the United States and the association between geographic accessibility to ERCP-performing hospitals and biliary interventions patients receive. This is a retrospective cohort study using the Surveillance, Epidemiology, and End Results (SEER)-Medicare database for pancreatic cancer from 2005 to 2013. Multilevel models were used to examine the association between accessibility to ERCP hospitals within a 30- and 45-min drive from the patient's residential ZIP Code and the receipt of ERCP treatment. A two-step floating catchment area model was used to calculate the measure of accessibility based on the distribution across SEER regions. 7464 and 782 patients underwent ERCP and PTBD, respectively, over the study period. There were 808 hospitals in which 8246 patients diagnosed with pancreatic cancer in SEER regions from 2005 to 2013 received a procedure. Patients with high accessibility within both 30- and 45-min drive to an ERCP-performing hospital were more likely to receive an ERCP (30-min adjusted odds ratio [aOR]: 1.53, 95% confidence interval [CI]: 1.17-2.01; 45-min aOR: 1.31, 95% CI: 1.01-1.70). Furthermore, in the adjusted model, Black patients (vs. White) and patients with stage IV disease were less likely to receive ERCP than PTBD. Patients with pancreatic cancer and high accessibility to an ERCP-performing hospital were more likely to receive ERCP. Disparities in the receipt of ERCP persisted for Black patients regardless of their access to ERCP-performing hospitals.

Race, rurality and geographic accessibility to medication for opioid use disorder in the U.S.

ABSTRACT Disparities in geographic access to medication for opioid use disorder (OUD) are well documented. Further, historical implications of systemic racism and of the longstanding War on Drugs in the United States have driven both social and spatial inequities in access to treatment. This work builds on a previously published spatial access methodology that uses a gravity-based variant of the enhanced two-step floating catchment area model, to determine how OUD pharmacotherapy accessibility varies nationally at the census tract level. Medication for OUD (MOUD) accessibility scores are then analyzed by rurality and racial/ethnic segregation. The Getis-Ord Gi* statistic was used to identify clusters of high or low accessibility to MOUD, while the interaction index was used as a measure of segregation to assess the racial/ethnic population distribution. The results of the clustering statistic, and the associated significance values were then compared to rurality and interaction using the Chi-Square test to determine if hot or cold areas of access are independent of rurality and racial/ethnic spatial distributions. Lastly, the percentage of buprenorphine providers at capacity by census tract was calculated using the binary ‘at-capacity’ data attribute associated with each SAMHSA buprenorphine provider record. The results demonstrate distinct spatial variability of MOUD resources based on urbanicity and racial makeup that have significant implications for intervention or policy reform that seeks to encourage equal access to both treatment modalities.

Correlating Access to Primary Medical Care and Veterinary Care Providers: A Novel Application of Spatial Gravity Modelling.

Increasingly, health professionals are recognizing the need for a more holistic, or One Health, approach to wellness. Companion animals share the lives and homes of many Americans, and yet little research exists on the intersection of disparities of access to veterinary care and access to human health care. This research aims to fill that gap by exploring the use of a spatial model that identifies the relationship of supply and demand while also considering reductions as a function of travel time to a care facility. Four counties in Alabama were analyzed at the census tract level to determine the supply of primary care physicians and veterinary care providers. This research provides a unique application of the Enhanced Two-Step Floating Catchment Area model by independently examining access to each type of care and then comparing both access supply values at the census level. Results indicated a statistically significant positive relationship between access to both types of care, implying areas with lower access to primary care have concomitantly low access to veterinary care. Implications for practice include the introduction of this methodological approach, identification of future parameter specification research to improve the approach, and identification of an area of significant concern in the One Health framework. Further, the results can inform solution strategies such as offering integrated care interventions for both humans and their companion animal household members with direct use for policymakers aimed at increasing equitable access to health care across the One Health spectrum.

The Contributions of Population Distribution, Healthcare Resourcing, and Transportation Infrastructure to Spatial Accessibility of Health Care.

Population demand, healthcare resourcing, and transportation linkage are considered as major determinants of spatial access to health care. Temporal changes of the 3 determinants would result in gain or loss of spatial access to health care. As a remarkable milestone achieved by Targeted Poverty Reduction Project launched in China, the significant improvements in spatial access to health care served as an ideal context for investigating the relative contributions of these 3 determinants to the changes in spatial access to health care in a rural county. A national level poverty-stricken county, Chishui county from Guizhou province, China, was chosen as our study area. The enhanced two-step floating catchment area model and the chain substitution method were employed for analysis. The relative contributions of the 3 determinants demonstrated variations with villages. The relative contributions of healthcare resourcing were positive in all villages as indicated by sharp increases in healthcare resources. Population changes and transportation infrastructure expansion had both negative and positive effects on spatial access to health care for different villages. Decisionmakers should take into account the duration of travel time spent between where people live, where transport hubs are located, and where healthcare services are delivered in the process of formulating policies toward rural healthcare planning. For villages with poorly-established infrastructure, the optimization of population distribution and healthcare resourcing should be considered as the priority. A stronger marginal effect would be induced by transportation infrastructure expansion with increased spatial accessibility. This study provides empirical evidences to inform healthcare planning in low- and middle-income countries.

Impact of traffic congestion on spatial access to healthcare services in Nairobi.

Geographic accessibility is an important determinant of healthcare utilization and is critical for achievement of universal health coverage. Despite the high disease burden and severe traffic congestion in many African cities, few studies have assessed how traffic congestion impacts geographical access to healthcare facilities and to health professionals in these settings. In this study, we assessed the impact of traffic congestion on access to healthcare facilities, and to the healthcare professionals across the healthcare facilities. Using data on health facilities obtained from the Ministry of Health in Kenya, we mapped 944 primary, 94 secondary and four tertiary healthcare facilities in Nairobi County. We then used traffic probe data to identify areas within a 15-, 30- and 45-min drive from each health facility during peak and off-peak hours and calculated the proportion of the population with access to healthcare in the County. We employed a 2-step floating catchment area model to calculate the ratio of healthcare and healthcare professionals to population during these times. During peak hours, <70% of Nairobi's 4.1 million population was within a 30-min drive from a health facility. This increased to >75% during off-peak hours. In 45 min, the majority of the population had an accessibility index of one health facility accessible to more than 100 people (<0.01) for primary health care facilities, one to 10,000 people for secondary facilities, and two health facilities per 100,000 people for tertiary health facilities. Of people with access to health facilities, a sub-optimal ratio of <4.45 healthcare professionals per 1,000 people was observed in facilities offering primary and secondary healthcare during peak and off-peak hours. Our study shows access to healthcare being negatively impacted by traffic congestion, highlighting the need for multisectoral collaborations between urban planners, health sector and policymakers to optimize health access for the city residents. Additionally, growing availability of traffic probe data in African cities should enable similar analysis and understanding of healthcare access for city residents in other countries on the continent.

Measuring equality in access to urban parks: A big data analysis from Chengdu.

Spatial equality of parks is a significant issue in environmental justice studies. In cities with high-density development and limited land resources, this study uses a supply-demand adjusted two-step floating catchment area model (2SFCA), paying attention to residents' subjective preferences and psychological accessibility. It assesses equality of access to urban parks from two dimensions: spatial equality and quantitative equality at a fine scale of 100 × 100 m grid resolution. The spatial equality of urban parks in Chengdu is measured under different transportation modes (walking, cycling, and driving) based on multi-source geospatial big data and machine learning approaches. The results show: (1) There were significant differences in the spatial distribution of park accessibility under different modes of transportation. The spatial distribution under walking was significantly influenced by the park itself, while the distribution of rivers significantly influenced the spatial distribution under cycling and driving; (2) Accessibility to urban parks was almost universally equal in terms of driving, relatively equal in terms of cycling, and seriously unequal in terms of walking; (3) Spatial local autocorrelation analysis shows that park accessibility tended to be significantly clustered, with little spatial variation; and (4) The supply and demand of urban parks were relatively equal. The results can help urban planners to formulate effective strategies to alleviate spatial inequality more reasonably and precisely. The applied research methods can further improve the system of scientific evaluation from a new perspective.

Geographic disparities in access to Medication for Opioid Use Disorder across US census tracts based on treatment utilization behavior

Drug overdose is the leading cause of accidental death in the U.S. with deaths from opioid overdose occurring at a higher rate in rural areas. The gaps in the provision of healthcare services have been exacerbated by the opioid crisis leaving vulnerable populations without access to preventative care and education, harm reduction, both chronic and acute treatment of the symptoms of opioid use disorder (OUD), and long-term psychological support for those with OUD and their families. There has been a call in the literature -and a federal mandate-for increased access to opioid treatment facilities, but to date this access has not been operationalized using best practices in geography. Medication for Opioid Use Disorder (MOUD) with FDA-approved methadone or buprenorphine has been shown to increase treatment retention, reduce opioid use and associated health and societal harms, and reduce opioid related overdose, and as such is considered the most effective treatment for OUD. The objective of this study is to examine U.S. adults' spatial access to MOUD — specifically locations of certified Opioid Treatment Programs (OTPs) and DATA-waived Buprenorphine providers. A gravity-based variant of the enhanced two-step floating catchment area model is employed, where friction of distance is based on previously published willingness to travel distances for patients visiting OTPs, to assess how opioid agonist treatment accessibility varies across the nation. Findings suggest that there are extensive ‘treatment deserts’ where there is little to no physical access to MOUD, especially in rural areas. The significance of this work lies in the incorporation of treatment utilization behavior in the access metric, and the continued confirmation of gaps in access to OUD services despite federal efforts to improve accessibility.

Measuring COVID-19 vaccination coverage: an enhanced age-adjusted two-step floating catchment area model

BackgroundThere are only limited studies on access to COVID-19 vaccines and identifying the most appropriate health centres for performing vaccination in metropolitan areas. This study aimed to measure potential spatial access to COVID-19 vaccination centres in Mashhad, the second-most populous city in Iran.MethodsThe 2021 age structure of the urban census tracts was integrated into the enhanced two-step floating catchment area model to improve accuracy. The model was developed based on three different access scenarios: only public hospitals, only public healthcare centres and both (either hospitals or healthcare centres) as potential vaccination facilities. The weighted decision-matrix and analytic hierarchy process, based on four criteria (i.e. service area, accessibility index, capacity of vaccination centres and distance to main roads), were used to choose potential vaccination centres looking for the highest suitability for residents. Global Moran’s index (GMI) was used to measure the spatial autocorrelation of the accessibility index in different scenarios and the proposed model.ResultsThere were 26 public hospitals and 271 public healthcare centres in the study area. Although the exclusive use of public healthcare centres for vaccination can provide the highest accessibility in the eastern and north-eastern parts of the study area, our findings indicate that including both public hospitals and public healthcare centres provide high accessibility to vaccination in central urban part. Therefore, a combination of public hospitals and public healthcare centres is recommended for efficient vaccination coverage. The value of GMI for the proposed model (accessibility to selected vaccination centres) was calculated as 0.53 (Z = 162.42, P < 0.01). Both GMI and Z-score values decreased in the proposed model, suggesting an enhancement in accessibility to COVID-19 vaccination services.ConclusionsThe periphery and poor areas of the city had the least access to COVID-19 vaccination centres. Measuring spatial access to COVID-19 vaccination centres can provide valuable insights for urban public health decision-makers. Our model, coupled with geographical information systems, provides more efficient vaccination coverage by identifying the most suitable healthcare centres, which is of special importance when only few centres are available.Graphic abstract

Analyzing accessibility to fire stations: A floating catchment area model for stochastic transportation networks with travel time correlation

AbstractImproving the spatial accessibility of fire stations is a key factor in minimizing property loss and reducing injuries and deaths. Most existing studies neglect the effect of travel time correlation and uncertainty on the level of accessibility in non‐normally distributed networks. In this article, a two‐step floating catchment area (2SFCA) model is introduced to measure accessibility in correlated non‐normal uncertain transportation networks. The model extends the conventional 2SFCA measures by considering the catchment area of supply and demand locations in stochastic contexts. The proposed measure is applied to a study area to investigate the impacts of travel time correlation, travel time uncertainty, and non‐normal distributions on the accessibility value. It is further used to analyze access inequality between different areas of the case study and to identify segregated places in terms of accessibility to the fire stations. In addition, the conventional 2SFCA measure is executed to provide an evaluation of the outputs of the proposed model. Results highlight significant difference between the introduced model and the other existing measure. They also show inequality of accessibility in the study area and the way that the model parameters affect the accessibility level. Furthermore, results offer several methodological implications for accessibility analysis in time‐dependent networks.

Geospatial Analysis and Research on Social and Spatial Inequality of Compulsory Education: A Case Study of Hangzhou, China

Equal compulsory education is an important way to realize social and spatial equality, while the uneven allocation of educational resources in different regions and groups results in inequality of opportunity and solidification of social strata. Traditional research conducted on the basis of fixed search range ignores the special institutional background of Chinese school district system. In this paper, an improved Gaussian two‐step floating catchment area model is developed taking into consideration the school district system, while the bivariate local spatial analysis method and geographically weighted regression model are employed to study the social and spatial differentiation of compulsory education accessibility and its capitalization effects in Hangzhou. Results show that (1) the improved Gaussian two‐step floating catchment area model is more in line with the national condition of China’s “nearby schooling” policy; (2) the accessibility of compulsory schools in Hangzhou shows an obvious core‐periphery typology, and the aggregation effect of primary school accessibility is more significant than that of secondary schools; (3) compared to groups with high socioeconomic status, vulnerable groups are highly disadvantaged in terms of access to educational services; (4) spatial heterogeneity exists in education capitalization, and the areas where education accessibility has the strongest impact on housing prices are in the central city with rich high‐quality educational resources; (5) high‐quality educational resources, high‐priced communities, clusters of high socioeconomic status groups, and communities enjoying high‐level education accessibility are highly consistent in all spaces, which is the spatial expression of educational inequality. The research on Hangzhou, a regional central city, provides a theoretical basis and technical support for the humanistic shift in the allocation of educational resources.

A geospatial analysis of Type 2 Diabetes Mellitus and the food environment in urban New Zealand

The aim of this research is to analyse the spatial epidemiology of Type 2 Diabetes Mellitus (T2DM) and investigate associations with the built environment in urban New Zealand. Data on T2DM was sourced from the New Zealand Virtual Diabetes Register (2016), and data on environmental variables sourced from the Ministry for Primary Industries and Territorial Authorities (2013–2016). Novel measures of the built environment using an enhanced two-step floating catchment area model were established using data on fast food outlets, takeaways, dairy/convenience stores, supermarkets and fruit/vegetable stores. Rates of T2DM per 1000 population and standardised morbidity ratios were computed and visualised for all urban areas. Getis Ord was used to assess spatial clustering, and Bayesian modelling was used to understand associations between T2DM and environmental variables. Results indicate that T2DM is influenced by demographic factors, spatially clustered and associated with accessibility to environmental exposures. Health-promoting resources, such as fruit/vegetable stores, were shown to have a consistently protective effect on T2DM while those considered detrimental to health showed varying, and largely insignificant, associations. This is the first study in New Zealand to spatially quantify the effects of multiple environmental exposures on population level T2DM for all urban areas using a geospatial approach. It has implications for both policy and future research efforts as a deeper knowledge of local environments forms a basis on which to better understand spatial associations between the built environment and health, as well as formulate policy directed toward environmental influences on chronic health conditions.

Modeling spatial access to cervical cancer screening services in Ondo State, Nigeria

BackgroundWomen in low- and middle-income countries (LMIC) remain at high risk of developing cervical cancer and have limited access to screening programs. The limits include geographical barriers related to road network characteristics and travel behaviors but these have neither been well studied in LMIC nor have methods to overcome them been incorporated into cervical cancer screening delivery programs.MethodsTo identify and evaluate spatial barriers to cervical cancer prevention services in Ondo State, Nigeria, we applied a Multi-Mode Enhanced Two-Step Floating Catchment Area model to create a spatial access index for cervical cancer screening services in Ondo City and the surrounding region. The model used inputs that included the distance between service locations and population centers, local population density, quantity of healthcare infrastructures, modes of transportation, and the travel time budgets of clients. Two different travel modes, taxi and mini bus, represented common modes of transit. Geocoded client residential locations were compared to spatial access results to identify patterns of spatial access and estimate where gaps in access existed.ResultsOndo City was estimated to have the highest access in the region, while the largest city, Akure, was estimated to be in only the middle tier of access. While 73.5% of clients of the hospital in Ondo City resided in the two highest access zones, 21.5% of clients were from locations estimated to be in the lowest access catchment, and a further 2.25% resided outside these limits. Some areas that were relatively close to cervical cancer screening centers had lower access values due to poor road network coverage and fewer options for public transportation.ConclusionsVariations in spatial access were revealed based on client residential patterns, travel time differences, distance decay assumptions, and travel mode choices. Assessing access to cervical cancer screening better identifies potentially underserved locations in rural Nigeria that can inform plans for cervical cancer screening including new or improved infrastructure, effective resource allocation, introduction of service options for areas with lower access, and design of public transportation networks.

Urban Green Space Accessibility and Distribution Equity in an Arid Oasis City: Urumqi, China

Urban green space (UGS) is crucial to the healthy development of urban residents. However, UGS that is accessible can benefit residents to an even greater degree. Based on the two-step floating catchment area model (2SFCA) and the location quotient (LQ), we analyzed the changes from 1999 to 2019 in UGS walking accessibility and equity in built-up areas of Urumqi at different administrative levels, and how UGS policy affects the improvement of accessibility. The results showed that UGS accessibility and equity are not evenly distributed at different administrative levels and UGS categories. Although the overall UGS accessibility and equity has improved with policy implementation, these changes are caused by metro-level UGS construction in urban fringe areas. The improvement in UGS accessibility at the neighborhood level in densely populated areas is neglected, which leads to a mismatch between UGS construction and population distribution. In addition, the accessibility of UGS is also limited by geographical location, population density, road distribution, and water shortage in arid metropolitan Urumqi. Our research results provide a theoretical basis for Urumqi and other cities in the optimization of UGS structure and the realization of social equity.

Dynamic healthy food accessibility in a rapidly urbanizing metropolitan area: Socioeconomic inequality and relative contribution of local factors

The socioeconomic status (SES) related disparities in healthy food accessibility have been heatedly debated. Theoretically, a gap remains in the literature about how healthy food accessibility changes over time and the relative contribution of local factors to the change. Methodologically, one main obstacle to this issue emerges on how to address the nested structural interactions among SESs across different levels. This paper first proposes a novel theoretical framework on healthy food accessibility from a spatiotemporally dynamic perspective. Guided by this framework, we employ the enhanced two-step floating catchment area model to examine the dynamic accessibility to four types of healthy food stores (i.e., vegetable markets, supermarkets, seafood markets, and fruit stores) from 2016 to 2018 across communities within the Hangzhou metropolitan area, China. The chain substitution method is further utilized to quantify the relative contributions of local factors, including population demand, healthy food supply, and transportation linkage. Multilevel regression is finally applied to analyze the associations between healthy food accessibility and the nested SESs across community and subdistrict levels. Results reveal that the dynamics of healthy food accessibility and the contributions of the local factors substantially vary depending on the type of healthy food stores and over time. Social inequality in accessibility to supermarkets and fruit stores is much greater than that to vegetable markets. The impact of the SES at the subdistrict level is greater than that at the community level. This study demonstrates a new methodological procedure and can offer new insights into healthy food accessibility in rapidly urbanizing metropolitan areas.

Disparity in Spatial Access to Public Daycare and Kindergarten across GIS-Constructed Regions in Seoul, South Korea

In developed countries with decreasing fertility rates, the provision of public daycare and kindergarten (PDK) is considered to be an important policy for boosting national birth rates. Since PDK is free, its spatial accessibility becomes the most critical factor for parents in choosing the service. The study uses the popular two-step floating catchment area model (2SFCA) to analyze the spatial accessibility of PDKs at a 100 m × 100 m cell level in Seoul, South Korea. A GIS-automated regionalization method, Mixed-Level Regionalization (MLR), is employed to divide the study area into homogenous regions based on a concentrated disadvantage index (CDI). The analysis then proceeds to examine the disparity of PDK accessibility across these constructed regions. The result empowers parents to be informed of the access of PDKs in their current neighborhoods or to look for neighborhoods with adequate access. Several policy measures are proposed for improving overall accessibility of PDKs and more so for underserved populations.

Enhancing the Two-Step Floating Catchment Area Model for Community Food Access Mapping: Case of the Supplemental Nutrition Assistance Program

In this article, a Gaussian-based two-step floating catchment area (2SFCA) model is applied to evaluate the geographical accessibility to Supplemental Nutrition Assistance Program (SNAP)-authorized retailers. First, the proposed method considers the interaction between the food supply (in terms of categorized benefit redemptions) and demand (in terms of benefit-receiving households). Second, the model is used to visualize food access patterns at the level of refined administrative units (i.e., census block groups). The developed food access metric was compared to the U.S. Department of Agriculture (USDA) Food Access Research Atlas, justifying the validity of this new method for small area estimation. The following are important observations: (1) the choice of catchment size had a considerable impact on the accessibility measure in urban areas (or when small statistical units are used); (2) the 2SFCA measurement had a higher level of correspondence with that of the USDA Atlas at a smaller catchment size for identifying low food access units; and (3) there was no significant inequality regarding SNAP accessibility with respect to different socioeconomic deprivation variables. This new method can better assist the SNAP administration with store authorization on a refined geographic scale. Key Words: food access, inequality, scale, Supplemental Nutrition Assistance Program (SNAP), two-step floating catchment area (2SFCA).