Walkable Distance Research Articles

Spatial uncertainty and environment-health association: An empirical study of osteoporosis among “old residents” in public housing estates across a hilly environment

BackgroundBuilt environment can influence physical conditions of older adults (e.g. osteoporosis). However, traditional methods using 2-dimensional circular buffer as a spatial structure to measure neighbourhood effect may create bias in health estimation, especially for the hilly and compact environment across low-income neighbourhoods (e.g. public housing estates). MethodsWe evaluated the environmental influences on self-reported osteoporosis among “old residents” (age≥65) in Hong Kong (n = 2077). Twelve public housing estates across hilly neighbourhoods in Hong Kong were selected as study sites. A cross-validated approach was developed to evaluate four spatial structures (2D circular, 2D service area, 3D circular, 3D service area). To determine problems of spatial uncertainty, we compared odds ratios (OR) and differences in effect sizes from models using different spatial structures. When all adjusted models achieve significant results based on 95% confidence intervals (CI) and with all positive/negative ORs, this study reported to have reached “a result with consistency”. Results from the 3D service area were then used to explain the environment-health relationship. ResultsDifferent spatial structures can yield different results. Particularly, circular buffers overestimated environmental effects on self-reported osteoporosis. Overestimated measures were related to walkability and accessibility but not greenery. Specifically, results from the 3D service area showed that more public space and health facilities within a walkable distance (500 m) from a location of subject's residence were negatively associated with self-reported osteoporosis (adjusted ORs: 0.44 [0.29, 0.66]; 0.94 [0.90, 0.99]). However, more major transport facilities at the immediate distance from residence (200 m) was positively associated with self-reported osteoporosis (adjusted OR: 1.11 [1.01, 1.23]). ConclusionsPhysical conditions (e.g. osteoporosis) of older adults living in a hilly neighbourhood could be driven by walking behaviours. It is necessary to include local terrain and road network to define a walkable neighbourhood for environment-health estimations to minimize spatial bias.

The Land Use and Individual Correlates of Pedestrian Commuting: Who Walks to Their Work or Place of Study in the Large Cities of the MENA Region?

The body of research on the determinants of pedestrian commuting and the characteristics of on-foot commuters at the international level and especially in the Global South is inconsistent; hence, this study focuses on this topic with the case of megacities in the Middle East and North Africa. The study is based on 8284 face-to-face interviews with respondents in the three cities, 4543 of whom worked, and of those 4543, 658 individuals walked to their work or place of study. By using binary logistic regression, the determinants of walking to work were identified. Age, household car ownership, last relocation time, intersection density, number of accessed facilities from home, average walking accessibility to neighborhood amenities, and commuting distance are the significant determinants of on-foot commuting. The study identifies younger commuters with fewer cars or no driving license living in neighborhoods with connected street networks as the walkers. The results of the Mann–Whitney U Test show that there is a significant difference between the values of these determinants for walking commuters and those who commute by other modes. Based on these findings, this paper encourages urban planners and decision-makers of the MENA region to use urban land use, including street networks and access to local facilities, to motivate commuters to commute on foot, especially those who work within a walkable distance to their work or place of study.

“Planned greenspace” or “natural greenspace” in a high-density city with compact environment? An empirical study of osteoporosis among senior population

Osteoporosis is a major physical health issue in healthy ageing among urban populations. However, few studies have investigated how greenspace can influence osteoporosis, especially to those who lived in a compact city with high-density living environment. Furthermore, no studies have investigated how “planned greenspace” and “natural greenspace” can separately influence osteoporosis among senior population. We hereby conducted an empirical study to evaluate the relationship between osteoporosis, “planned greenspace” and “natural greenspace”, based on the use of land use data derived from local geospatial information and satellite images. Our results showed that seniors who were 1) aged, 2) female, 3) less educated, 4) smokers, and 5) with chronic respiratory diseases were associated with osteoporosis. Considering factors of greenspace, a higher percentage of planned greenspace surrounding the residence may be a protective factor while natural greenspace did not influence the individuals. Specifically, a 10% increase of planned greenspace within the 600-m radius area surrounding the residence was negative associated with osteoporosis (−2.8% [-5.1%, −0.5%]). Based on our results, development of planned greenspace may be necessary, as compact built environment of a high-density city often resulted in a lack of planned greenspace for physical activities. Along with the World Health Organization (WHO) guidelines for an age-friendly city, our findings suggest that improving the planned greenspace in a walkable distance around one's neighboring environment is a potential strategy for prevention of osteoporosis and related physical health issues as well as for life quality improvement among the senior population.

Improvements in space-time accessibility as outcomes of heavy rail transit development in the sprawled residential district. Empirical evidence from Gdańsk

The sustainable mobility paradigm is essential to cities’ climate mitigation. Transit-oriented development (TOD) supporting the concentration of housing, workplaces, facilities, and services within a walkable distance of transport nodes connected by efficient public transport results in the use of sustainable mobility implementation. Despite the growing scientific interest in TOD, the legal, economic, cultural, and physical obstacles complicate and slow down its implementation process. This article provides new insight into the outcomes of planned heavy rail transit (HRT) development across the sprawled residential district, which emerged due to market-driven housing development, intense individual motorisation, and permissive spatial policy that enables extensive housing without relevant transit investments. Based on quantitative data regarding spatialities of the case study area, space–time accessibility was the primary research method. Despite the unfavourable local context to mass transit, the investigation reveals significant planned HRT line spatial-time accessibility attempts. The most significant is the by-transit travel time reduction and an increase in to-transit accessibility. Due to urban sprawl outcomes, the HRT line requires an extensive feeder system. It increases operational costs and risks the reliability of the whole trunk-and-feeder system due to possible feeder operation disturbance resulting from road congestion. The study outcomes yield significant implications for urban transport policy.

Creating grocery delivery hubs for food deserts at local convenience stores via spatial and temporal consolidation

For many socioeconomically disadvantaged customers living in food deserts, the high costs and minimum order size requirements make attended grocery deliveries financially non-viable, although it has a potential to provide healthy foods to the food insecure population. This paper proposes consolidating customer orders and delivering to a neighborhood convenience store instead of home delivery. We employ an optimization framework involving the minimum cost set covering and the capacitated vehicle routing problems. Our experimental studies in three counties in the U.S. suggest that by spatial and temporal consolidation of orders, the deliverer can remove minimum order-size requirements and reduce the delivery costs, depending on various factors, compared to attended home-delivery. We find the number and size of time windows for home delivery to be the most important factor in achieving temporal consolidation benefits. Other significant factors in achieving spatial consolidation include the capacity of delivery vehicles, the number of depots, and the number of customer orders. We also find that the number of partner convenience stores and the walkable distance parameter of the model have a significant impact on the number of accepted orders, i.e., the service level provided by the deliverer. The findings of this study imply consolidated grocery delivery as a viable solution to improve fresh food access in food deserts. In light of the recent global pandemic and its exacerbating effects on food insecurity, the innovative solution proposed in this paper is even more relevant and timely.

Time-Use and Spatio-Temporal Variables Influence on Physical Activity Intensity, Physical and Social Health of Travelers

Using a multi-dimensional three-week household time-use and activity diary, this study aims to investigate the interaction between time-use and activity travel participation, built environment, leisure-time physical activity, travel parameters, and physical intensity on physical and social health. The relationship between time-use and activity travel participation is complex. Therefore, physical activity (PA) intensity is assumed to intermediate the relationship between endogenuous and exogenous variables. This study use a comprehensive set of data that was collected at a household level for twenty-one (21) consecutive days. A total of 732 individuals and 191 households were recorded, representing 0.029% total population of Bandung Metropolitan Area (BMA). The data analyzed with descriptive and linear regression analysis using Statistical Package for Social Sciences SPSS version 26.0.0 software (IBM: Armonk, NY, USA). An advanced model, such as the hierarchical Structural Equation Model (SEM), is used to validate the relationship between activity patterns and health parameters. The estimated results indicate that a minute increase in public transport mode has an 8.8% positive correlation with physical health and 9.0% with social health. Furthermore, an increase in the one-minute duration of in-home maintenance and out-of-home leisure activities are positively correlated by 2.9% and 3.2%, respectively, with moderate-intensity PA and by 4.5% and 1.8% strenuous-intensity PA. Additionally, high accessibility and availability of basic amenities at a walkable distance and using auxiliary time in social activities are significantly correlated with better physical and social health. Moreover, this study adopted multidisciplinary approaches for better transport policy and a healthier society with a better quality of life.

Using the location-allocation P-median model for optimising locations for health care centres in the city of Jeddah City, Saudi Arabia.

Considering spatial accessibility of health services is a critical part in the planning and management of health services. There is evidence that poor geographical locations can obstruct prompt basic health care services to some population sections. We developed a location-allocation P-median model for health centres after analysing their sites, demand location of health services and the road network in Jeddah, Saudi Arabia. This model attempts to optimize health care services network and to put forward location recommendations to maximise service coverage. Our model is shown to be useful as it provides a robust evidence base to urban planners and policymakers responsible for making spatial decisions for the development of the health sector. Besides, it follows the paradigm of new urbanism that encourages decentralisation of essential facilities including basic healthcare in cities, where emphasis is on offering all basic services within walkable distances of 15 min. or less.

Evaluation of neighborhood resources and mental health in American military Veterans using geographic information systems

Neighborhood-level social determinants are increasingly recognized as factors shaping mental health in adults. Data-driven informatics methods and geographic information systems (GIS) offer innovative approaches for quantifying neighborhood attributes and studying their influence on mental health. Guided by a modification of Andersen’s Behavioral Model of Health Service Use framework, this cross-sectional study examined associations of neighborhood resource groups with psychological distress and depressive symptoms in 1,528 U.S. Veterans. Data came from the Veteran Affairs (VA) Health Services Research and Development Proactive Mental Health trial and publicly available sources. Hierarchical clustering based on the proportions of neighborhood resources within walkable distance was used to identify neighborhood resource groups and generalized estimating equations analyzed the association of identified neighborhood resource groups with mental health outcomes. Few resources were found in walkable areas except alcohol and/or tobacco outlets. In clustering analysis, four meaningful neighborhood groups were identified characterized by alcohol and tobacco outlets. Living in an alcohol-permissive and tobacco-restrictive neighborhood was associated with increased psychological distress but not depressive symptoms. Living in urban or rural areas and access to VA care facilities were not associated with either outcome. These findings can be used in developing community-based mental health-promoting interventions and public health policies such as zoning policies to regulate alcohol outlets in neighborhoods. Augmenting community-based services with Veteran-specialized services in neighborhoods where Veterans live provides opportunities for improving their mental health.

Utilisation of Community Audio Towers in Health Education for Prevention of Cervical Cancer by Health Workers in Kyotera District, Uganda: A Cross-Sectional Study.

PurposeCommunity audio towers (CATs) are a communication resource that can be utilized by public health practitioners to enhance health communication in rural and peri-urban settings. However, information on availability of this channel of communication for use in health education and promotion remains scanty. We determined the availability of CATs for use in cervical cancer health education among health workers for prevention of cervical cancer in Kyotera District, Uganda.MethodsUsing a cross-sectional study design, health workers were randomly selected from health facilities in Kyotera District. Eligible participants were health workers who had worked in the district for at least one year. A pre-tested study questionnaire was self-administered. Descriptive statistics were used to determine availability and use of CATs, while factors associated with the use of CATs were determined by logistic regression analysis.ResultsBetween March and April 2020, 160 health workers were enrolled, and of these, 102 (63.8%) were females and 69 (43.1%) were nurses. Most of them, ie, 143 (89.4%) reported that CATs were within walkable distance from their workplaces; 140 (87.5%) indicated that CATs are conveniently located, and 129 (80.6%) reported that it was easy to secure airtime to sensitise communities on health issues. Only 26 (16.3%) had ever used CATs for cervical cancer health education. Health workers at facilities without a plan that includes CATs as a channel of health communication were less likely to utilise CATs (OR = 0.04, 95% CI (0.0043–0.37), p = 0.005) while those who had ever managed a patient with cervical cancer (OR = 16.48, 95% CI (3.4–79.7), p < 0.001) were more likely to utilise CATs.ConclusionAlthough CATs were deemed readily available, there was low utilisation for cervical cancer education and promotion of preventive services by health workers. Health facilities need to strategically include CATs in their plans to increase utilisation.

Using Exploratory Spatial Analysis to Understand the Patterns of Adolescents’ Active Transport to School and Contributory Factors

Active transport to school (ATS) is a convenient way for adolescents to reach their recommended daily physical activity levels. Most previous ATS research examined the factors that promote or hinder ATS, but this research has been of a global (i.e., non-spatial), statistical nature. Geographical Information Science (GIS) is widely applied in analysing human activities, focusing on local spatial phenomena, such as distribution, autocorrelation, and co-association. This study, therefore, applied exploratory spatial analysis methods to ATS and its factors. Kernel Density Estimation (KDE) was used to derive maps of transport mode and ATS factor distribution patterns. The results of KDE were compared to and verified by Local Indicators of Spatial Association (LISA) outputs. The data used in this study was collected from 12 high schools, including 425 adolescents who lived within walkable distance and used ATS or MTS in Dunedin New Zealand. This study identified clusters and spatial autocorrelation, confirming that the adolescents living in the south of the city, who were female, attended girls-only schools, lived in more deprived neighbourhoods, and lived in neighbourhoods with higher intersection density and residential density used more ATS. On the other hand, adolescents who were male, attended boys-only schools, lived in less deprived neighbourhoods, had more vehicles at home, and lived in neighbourhoods with medium level intersection density and residential density used more ATS in the northwest of the city as well as some part of the city centre and southeast of the city. The co-association between spatial patterns of the ATS factors and the ATS usages that this study detected adds to the evidence for autocorrelation underpinning ATS users across the study area.

The impact of perceived risk and disease prevention efficiency on outdoor activities and avoidance behaviors in the urban parks during COVID 19 pandemic

PurposeCOVID 19 has had a profound effect on peoples’ activities and the use of public spaces. Before the COVID 19 pandemic urban parks, as healthy places, were of the most favorable places for urban citizens, but nowadays no vitality is found in urban parks due to the absence of people. The perceived risk seems to affect peoples’ decision-making for the visit to urban parks. This study aims to examine the impact of COVID 19 perceived severity and vulnerability on peoples’ visit to the urban parks and further exercise avoidance. It is expected that the result of this study would shed light on the people’s perception of healthy urban parks to exercise during COVID 19.Design/methodology/approachThe participants were recruited from a neighborhood with the greenest and largest parks in Iran that were selected for the study. It was to assure that participants have access to the urban parks within their walkable distance. The mixed-method approach was applied to achieving the research goals. A total of 404 participants attended the survey. A series of semi-structured interviews were conducted to examine the strategies that reduce peoples’ worries about using urban parks during the COVID 19. Data were analyzed using SmartPLS.FindingsThe study hypothesized that peoples’ awareness of COVID 19 affects their perceived risk and disease prevention efficiency. Besides, it was hypothesized that perceived risk and efficacy effects outdoor activities worries exercise avoidance and behavioral avoidance in the urban parks. The result of the study supported the research hypothesis. The more knowledge people acquire of COVID 19 and the lack of efficacy of treatments, the higher they will avoid outdoor activities and exercise. The means of knowledge and perceived risk were higher than previously reported studies.Originality/valueThe result of this study is very important, as it statistically proves that peoples’ priorities and factors that affect their willingness to use public spaces are very much affected by their perception of a healthy environment. It also canonizes the role of facility managers in bringing peoples’ trust in the use of public spaces and more specifically urban parks during pandemic disease distributions.

Redrawing the Planners’ Circle

Problem, research strategy, and findings For decades, planners have been drawing circles of a quarter-mile radius to determine easily walkable distances for neighborhood and activity center planning. However, the radius of such “planners’ circles,” or walksheds, is often informed more by convention than by data. Here we examine walk-trip distances based on two national household travel surveys for the United States and Germany. We describe how walk distances vary by personal and trip characteristics, with a particular focus on trip purpose and pedestrian age. We conducted both univariate and multivariate analyses to compare patterns between the United States and Germany. The multivariate analysis examines quantile regressions for 50th, 75th, and 90th percentiles to understand both typical and longer walk distances. The observed distances that people walk vary significantly across age groups, trip purposes, and national contexts. Leisure trips tend to be longest, whereas shopping and errand trips tend to be shortest. There are substantial differences between the United States and Germany in the average lengths of walks (mean/median walk distance: Germany, 1,490/980 m, 0.93/0.61 miles; United States, 970/530 m, 0.60/0.33 miles) and in the effects of independent variables. A significant portion of the variation in walk-trip distances between the United States and Germany is likely due to Germany’s higher quality walk environments. Takeaway for practice Rather than always resort to a quarter-mile or 400-m radius, planners can use the data here to customize the size of the planners’ circle, or walkshed, they draw to take into account the primary trip purposes and demographic segments under consideration. Moreover, planners can draw circles with a shorter radius corresponding to the 50th percentile to plan for the most common walk-trip lengths while also considering larger circles corresponding to the 75th and 90th percentiles to provide more supportive and safer pedestrian environments for longer trips.

Implications of attending the closest school on adolescents’ physical activity and car travel in Dunedin, New Zealand

BackgroundHome-to-school distances and the need for students to be driven to/from school may limit adolescents' physical activity levels. School choice and school zoning policies can influence rates of active transport to/from school, and traffic volumes during school commuting times. This study aimed to quantify the effects of adolescents' enrolment in the closest school or not, on private vehicle use and adolescents’ physical activity levels in Dunedin city, New Zealand. MethodsNew Zealand Travel Survey data (2003–2013; 2493 Dunedin respondents) were analysed to examine school-travel related private motorised trips. Dunedin-specific data from adolescents (from six Dunedin non-integrated public schools without school zoning) were analysed including self-reported survey data on school travel modes (797 adolescents), distance to the current and closest schools (797 adolescents) and accelerometer-measured moderate-to-vigorous intensity physical activity (MVPA) (121 adolescents). ResultsDuring the school commute time (8–9 am and 3–4 pm), an estimated 11.5% of car trips (95% CI 7.8%–16.8%) and 12.5% of car distance driven (95% CI 8.8%–17.7%) were related to secondary-school travel with approximately half of these involving trip-chaining. Compared to adolescents living beyond cycling distance (>4 km) from their current school, adolescents living within walkable distance (≤2.25 km) and cyclable distance (>2.25-≤4 km) accumulated an additional 12.1 min (95% CI 7.0 to 17.2) and 6.1 min (95%CI 1.0 to 11.2) of daily MVPA during the school commute time, respectively. If adolescents currently enrolled at a distant school were to attend the closest school, they could accrue an additional 3.4 min MVPA during the 2-h school commute time period and school travel-related private car trips would be reduced by 7%. ConclusionsIn Dunedin, New Zealand, modest reductions in private vehicle traffic, particularly around schools, and increases in adolescents’ MVPA during the school commute period would be expected if all adolescents attended the closest school.

Creating Grocery Delivery Hubs for Food Deserts at Local Convenience Stores via Spatial and Temporal Consolidation

For many socioeconomically disadvantaged customers living in food deserts, the high costs and minimum order size requirements make attended grocery deliveries financially non-viable, although it has potential to provide healthy foods to the food insecure population. This paper proposes consolidating customer orders and delivering to a neighborhood convenience store instead of home delivery. We employ an optimization framework involving the minimum cost set covering and the capacitated vehicle routing problems. Our experimental studies in three counties in the U.S. suggest that by spatial and temporal consolidation of orders, the deliverer can remove minimum order-size requirements and reduce the delivery costs, depending on various factors, compared to attended home-delivery. We find the number and size of time windows for home delivery to be the most important factor in achieving temporal consolidation benefits. Other significant factors in achieving spatial consolidation include the capacity of delivery vehicles, the number of depots, and the number of customer orders. We also find that the number of partner convenience stores and the walkable distance parameter of the model, have a significant impact on the number of accepted orders, i.e., the service level provided by the deliverer. The findings of this study imply consolidated grocery delivery as a viable solution to improve fresh food access in food deserts. In light of the recent global pandemic, and its exacerbating effects on food insecurity, the innovative solution proposed in this paper is even more relevant and timely.

Predicting the use frequency of ride-sourcing by off-campus university students through random forest and Bayesian network techniques

Abstract This study used a survey technique to investigate factors that motivate the adoption and the usage frequency of ride-sourcing among students in a Malaysia public university. Two of the most broadly used machine learning techniques, Random Forest technique and Bayesian network analysis were applied in this study. Random Forest was employed to establish the relationship between ride-sourcing usage frequency and students' socio-demographic related factors, built environment considerations, and attitudes towards ride-sourcing specific factors. Random Forest identified 10 most important factors influencing university students’ use of ride-sourcing for different travel purposes, including study-related, shopping, and leisure travel. These important predictors were found to be indicators of the target variables (i.e., ride-sourcing usage frequency) in Bayesian network analysis. Bayesian network analysis identified the students' age (0.15), safety perception (0.32), and neighbourhood facilities in a walkable distance (0.21) as the most important predictors of the use of ride-sourcing among students to get to school, shopping, and leisure, respectively.

Determining transit nodes for potential transit-oriented development: Along the LRT corridor in Addis Ababa, Ethiopia

The aim of transit-oriented development (TOD) is to create a livable urban environment by improving the integration between land-use and transportation systems. The capital city of Ethiopia, Addis Ababa, aims to promote a sustainable transportation system by launching its first light rail transit (LRT) network to control the current pattern of increased congestion and the need for mass transport. Planning for TOD around existing transit stations helps achieve improved transit choice and encourages local economic development. Therefore, this article proposes a methodology to quantitatively measure the existing TOD in terms of a TOD index within the walkable distance of transit nodes by measuring the criteria that define TOD levels. The TOD index is calculated for areas of 22 stations on the East-West LRT line of Addis Ababa. Depending on the value of the TOD index, certain stations are identified to have a potential TOD but poor transit accessibility. With these results, the recommendation to improve TOD planning can become accurate for each station, depending on its relevant factors. Such results also help identify each station's potential for TOD planning and its improvements toward future local developments.

School proximity and census tract correlates of e-cigarette specialty retail outlets (vape shops) in central Texas.

E-cigarettes are the most widely used tobacco product among middle and high school students in the United States. This study investigates the proximity of e-cigarette retail outlets (vape shops) to middle and high schools in Austin, Texas, as well as the sociodemographic determinants of outlet presence, at the census tract level. A proximity analysis was conducted using school geo-data derived from the Texas Education Agency and vape shop geo-data derived from a validated online search. Logistic regressions using 5-year estimates of the 2014 American Community Survey were performed to determine the correlates of vape shop presence in census tracts. Overall, 20% of the census tracts in Austin, Texas, had at least one vape shop. The proportion of vape shop-containing census tracts that met the criteria for classification as a “poverty area” (36.5%) was greater than that of vape shop-free census tracts (26.3%). Vape shops were more likely to be present in census tracts classified as poverty areas; however, the odds of vape shop presence declined as the percentage of the non-Hispanic Black population and the percentage of persons aged 10–14 years in census tracts increased. About 40% of the vape shops were located within 0.5 miles of a middle or high school. Sociodemographic disparities exist in the e-cigarette retail environment. In addition to the need to address the disparities identified in this study, our results showing the presence of vape shops within walkable distances of schools calls for tighter regulations and continued surveillance around the marketing practices of e-cigarette retailers.

On the determinants of Uber accessibility and its spatial distribution: Evidence from Uber in Philadelphia

AbstractThis study investigates the impact of socioeconomics and demographic factors (e.g., population density, minority rate, age, gender, education, wealth, and crime) and transportation infrastructure (e.g., walk score, transit score, and bike score) on the accessibility of Uber in the city of Philadelphia. K‐means clustering is applied for initial data exploration. Based on the spatial model selection diagnostic tests, we developed maximum likelihood spatial lag models with queen contiguity spatial weight matrix. The results show that Uber accessibility is not balanced in different neighborhoods in Philadelphia. Uber is more accessible in denser areas with the high male population, better public transportation access and less access to amenities in the walkable distances. Moreover, we observed that Uber is more accessible in areas with a high crime rate. This observation shows that Uber has made it easier to get out of high crime rate areas. Finally, contribution in the literature on accessibility in ride‐sourcing networks is discussed. Findings are additionally used to provide managerial implications to mitigate discrimination in ride‐sourcing platforms.This article is categorized under: Application Areas &gt; Industry Specific Applications Algorithmic Development &gt; Spatial and Temporal Data Mining Commercial, Legal, and Ethical Issues &gt; Social Considerations

Hotspots of childhood obesity in a large metropolitan area: does neighbourhood social and built environment play a part?

BackgroundEffective place-based interventions for childhood obesity call for the recognition of the high-risk neighbourhoods and an understanding of the determinants present locally. However, such an approach is uncommon. In this study, we identified neighbourhoods with elevated prevalence of childhood obesity (‘hotspots’) in the Porto Metropolitan Area and investigated to what extent the socio-economic and built environment characteristics of the neighbourhoods explained such hotspots.MethodsWe used data on 5203 7-year-old children from a population-based birth cohort, Generation XXI. To identify hotspots, we estimated local obesity odds ratios (OR) and 95% confidence intervals (95%CI) using generalized additive models with a non-parametric smooth for location. Measures of the socio-economic and built environment were determined using a Geographic Information System. Associations between obesity and neighbourhood characteristics were expressed as OR and 95%CI after accounting for individual-level variables.ResultsAt 7 years of age, 803 (15.4%) children were obese. The prevalence of obesity varied across neighbourhoods and two hotspots were identified, partially explained by individual-level variables. Adjustment for neighbourhood characteristics attenuated the ORs and further explained the geographic variation. This model revealed an association between neighbourhood socio-economic deprivation score and obesity (OR = 1.014, 95%CI 1.004–1.025), as well as with the presence of fast-food restaurants at a walkable distance from the residence (OR = 1.37, 1.06–1.77).ConclusionsIn our geographic area it was possible to identify neighbourhoods with elevated prevalence of childhood obesity and to suggest that targeting such high-priority neighbourhoods and their environmental characteristics may help reduce childhood obesity.

Calibration of a transit route choice model using revealed population data of smartcard in a multimodal transit network

One of the major objectives of this study is to provide more realistic and accurate results related to transit passenger’s route choice behavior by using population data of revealed preference from smartcard transaction records. The smartcard data of the Seoul city provides both boarding and alighting location and time, which can make possible to trace each passenger’s actually used path trajectory with close to 100% market penetration of smartcard usage. This study built an abstract transit network with representative nodes by aggregating all near-by bus stops within walkable distance and with abstract paths by aggregating lines for a specific OD pair that run the same trajectory links by same transit modes. This complex and huge-scale transit network allowed to analyze the route choice behavior of transit passengers in a multimodal transit system that could not be found from the data of relatively small-size cities. This study selected OD pairs which had two or more alternative paths in order to analyze choice behavior requiring a plural alternative choice set. The number of the selected OD pairs are 124,393 pairs that are 33.9% of whole OD pairs that has two or more trip records. The calibration result showed that it is good statistically and logically to include the six explanatory variables in the utility function of the multinomial Logit model. Those are in-vehicle travel time, out-of-vehicle travel time, transfer penalty index, travel time reliability measure, and path circuity index.