Abstract Inequality to food access has always been a serious problem, yet it became even more cri... more Abstract Inequality to food access has always been a serious problem, yet it became even more critical during the COVID-19 pandemic, which exacerbated social inequality and reshaped essential travel. This study provides a holistic view of spatio-temporal changes in food access based on observed travel data for all grocery shopping trips in Columbus, Ohio, during and after the state-wide stay-at-home period. We estimated the decline and recovery patterns of store visits during the pandemic to identify the key socio-economic and built environment determinants of food shopping patterns. The results show a disparity: during the lockdown, store visits to dollar stores declined the least, while visits to big-box stores declined the most and recovered the fastest. Visits to stores in low-income areas experienced smaller changes even during the lockdown period. A higher percentage of low-income customers was associated with lower store visits during the lockdown period. Furthermore, stores with a higher percentage of white customers declined the least and recovered faster during the reopening phase. Our study improves the understanding of the impact of the COVID-19 crisis on food access disparities and business performance. It highlights the role of COVID-19 and similar disruptions on exposing underlying social problems in the US.
Hurricanes can have a significant impact on the functioning and capacity of healthcare systems. H... more Hurricanes can have a significant impact on the functioning and capacity of healthcare systems. However, little work has been done to understand the extent to which hurricanes influence local residents' spatial access to healthcare. Our study evaluates the change in spatial access to primary care physicians (PCPs) between 2016 and 2018 (i.e., before and after Hurricane Harvey) in Harris County, Texas. We used an enhanced 2-step floating catchment area (E2SFCA) method to measure spatial access to PCPs at the census tract level. The results show that, despite an increased supply of PCPs across the county, most census tracts, especially those in the northern and eastern fringe areas, experienced decreased access during this period as measured by the spatial access ratio (SPAR). We explain this decline in SPAR by the shift in the spatial distribution of PCPs to the central areas of Harris County from the fringe areas after Harvey. We also examined the socio-demographic impact in the SPAR change and found little variation in change among different socio-demographic groups. Therefore, public health professionals and disaster managers may use our spatial access measure to highlight the geographic disparities in healthcare systems. In addition, we recommend considering other social and institutional dimensions of access, such as users' needs, preferences, resource capacity, mobility options, and quality of healthcare services, in building a resilient and inclusive post-hurricane healthcare system.
Imperial journal of interdisciplinary research, 2016
Since the independence of Bangladesh in 1971, Motijheel Commercial Area has flourished as the mai... more Since the independence of Bangladesh in 1971, Motijheel Commercial Area has flourished as the main Central Business District (CBD) of Dhaka City attributable to its rapid pace of commercial development. However, the process of development in this area followed a spontaneous but unplanned manner. As a consequence, this CBD is continuously confronting two key urban problems: congestion and constriction- which are often considered as factors that necessitate urban regeneration. This paper focuses on identifying the scope of urban regeneration in Motijheel Commercial Area. The study recognizes the traffic congestion problem of Motijheel with the characteristics of high volume-capacity ratio, illegal on street parking, inefficient management of public transport system and absence of pedestrian friendly facilities. The issue of constriction is addressed as lack of opportunity for horizontal expansion of the CBD due to its densely developed surrounding area. Similar issues were experienced...
Transportation Research Record: Journal of the Transportation Research Board, 2021
Stay-at-home policies in response to COVID-19 transformed high-volume arterials and highways into... more Stay-at-home policies in response to COVID-19 transformed high-volume arterials and highways into lower-volume roads, and reduced congestion during peak travel times. To learn from the effects of this transformation on traffic safety, an analysis of crash data in Ohio’s Franklin County, U.S., from February to May 2020 is presented, augmented by speed and network data. Crash characteristics such as type and time of day are analyzed during a period of stay-at-home guidelines, and two models are estimated: (i) a multinomial logistic regression that relates daily volume to crash severity; and (ii) a Bayesian hierarchical logistic regression model that relates increases in average road speeds to increased severity and the likelihood of a crash being fatal. The findings confirm that lower volumes are associated with higher severity. The opportunity of the pandemic response is taken to explore the mechanisms of this effect. It is shown that higher speeds were associated with more severe cr...
The COVID-19 pandemic has severely impacted public transit services through a combination of plum... more The COVID-19 pandemic has severely impacted public transit services through a combination of plummeting ridership during the lockdown and subsequent budget cuts. This study investigates the equity impacts of reductions in accessibility due to public transit service cuts during COVID-19 and their association with urban sprawl. We evaluated accessibility to essential services such as grocery stores and both urgent and non-urgent health care across 22 cities across the United States in three phases during 2020: pre-lockdown, lockdown, and post-lockdown. We estimated the spatio-temporal coverage of transit service during the peak and off-peak periods in each phase. We found stark disparities in food and health care access for various socio-economic groups. Economically disadvantaged and suburban neighborhoods were more likely to lose food and health care access by public transit during COVID-19. In particular, transit service cuts worsened accessibility for population groups with multip...
The COVID-19 pandemic has profoundly reshaped urban mobility. During the lockdown, workers telewo... more The COVID-19 pandemic has profoundly reshaped urban mobility. During the lockdown, workers teleworked if possible and left home only for essential activities. Our study investigates the spatial patterns of essential travel and their socio-economic differences during the COVID-19 lockdown phase in comparison with the same period in 2019. Using data from Columbus, Ohio, we categorized travelers into high, moderate, and low socio-economic status (SES) clusters and modeled travel demand of SES clusters for both phases using spatially weighted interaction models. Then, we characterized the SES variability in essential travel based on frequently visited business activities from each cluster. Results suggest that disparities in travel across SES clusters existed prior to COVID-19 are exacerbated during the pandemic lockdown. The diffused travel pattern of high and moderate SES cluster became localized while the pre-existing localized travel pattern of low SES cluster became diffused. Durin...
This repository provides the data used in the manuscript entitled "Reducing public transit c... more This repository provides the data used in the manuscript entitled "Reducing public transit compounds social vulnerabilities during COVID-19" by A Kar, AL Carrel, HJ Miller, and HTK Le.
Dhaka, the capital city of Bangladesh, is one of the fastest growing megacities in the world. Wit... more Dhaka, the capital city of Bangladesh, is one of the fastest growing megacities in the world. With the rapid growth of population and high urbanization rate, Dhaka is bound to expand the borders to accommodate the growing need of space. But this expansion is already taking its toll in the form of environmental degradation and social injustice hampering the geographical sustainability in the process. This study proposes a controlled and well-planned development in the eastern fringe of Dhaka City (comprising of Badda, Satarkul and Vatara) to meet up the challenge of future accommodation requirements. The area being geographically vulnerable with lots of agricultural lands, water bodies and retention ponds, the prime concern is to ensure the geographic sustainability of the area and use all the natural features as a vital tool in the process of development. As a planning technique, Land Readjustment Scheme is applied in this regard. This report contains all the measures and proposals regarding the natural features of the study area as well as the whole process of the development scheme including a financial proposal to recover the cost of the development to make this plan financially viable. Finally, the outcome of the study shows that it can be well implemented as all the objectives are fulfilled to the fullest.
Abstract Inequality to food access has always been a serious problem, yet it became even more cri... more Abstract Inequality to food access has always been a serious problem, yet it became even more critical during the COVID-19 pandemic, which exacerbated social inequality and reshaped essential travel. This study provides a holistic view of spatio-temporal changes in food access based on observed travel data for all grocery shopping trips in Columbus, Ohio, during and after the state-wide stay-at-home period. We estimated the decline and recovery patterns of store visits during the pandemic to identify the key socio-economic and built environment determinants of food shopping patterns. The results show a disparity: during the lockdown, store visits to dollar stores declined the least, while visits to big-box stores declined the most and recovered the fastest. Visits to stores in low-income areas experienced smaller changes even during the lockdown period. A higher percentage of low-income customers was associated with lower store visits during the lockdown period. Furthermore, stores with a higher percentage of white customers declined the least and recovered faster during the reopening phase. Our study improves the understanding of the impact of the COVID-19 crisis on food access disparities and business performance. It highlights the role of COVID-19 and similar disruptions on exposing underlying social problems in the US.
Hurricanes can have a significant impact on the functioning and capacity of healthcare systems. H... more Hurricanes can have a significant impact on the functioning and capacity of healthcare systems. However, little work has been done to understand the extent to which hurricanes influence local residents' spatial access to healthcare. Our study evaluates the change in spatial access to primary care physicians (PCPs) between 2016 and 2018 (i.e., before and after Hurricane Harvey) in Harris County, Texas. We used an enhanced 2-step floating catchment area (E2SFCA) method to measure spatial access to PCPs at the census tract level. The results show that, despite an increased supply of PCPs across the county, most census tracts, especially those in the northern and eastern fringe areas, experienced decreased access during this period as measured by the spatial access ratio (SPAR). We explain this decline in SPAR by the shift in the spatial distribution of PCPs to the central areas of Harris County from the fringe areas after Harvey. We also examined the socio-demographic impact in the SPAR change and found little variation in change among different socio-demographic groups. Therefore, public health professionals and disaster managers may use our spatial access measure to highlight the geographic disparities in healthcare systems. In addition, we recommend considering other social and institutional dimensions of access, such as users' needs, preferences, resource capacity, mobility options, and quality of healthcare services, in building a resilient and inclusive post-hurricane healthcare system.
Imperial journal of interdisciplinary research, 2016
Since the independence of Bangladesh in 1971, Motijheel Commercial Area has flourished as the mai... more Since the independence of Bangladesh in 1971, Motijheel Commercial Area has flourished as the main Central Business District (CBD) of Dhaka City attributable to its rapid pace of commercial development. However, the process of development in this area followed a spontaneous but unplanned manner. As a consequence, this CBD is continuously confronting two key urban problems: congestion and constriction- which are often considered as factors that necessitate urban regeneration. This paper focuses on identifying the scope of urban regeneration in Motijheel Commercial Area. The study recognizes the traffic congestion problem of Motijheel with the characteristics of high volume-capacity ratio, illegal on street parking, inefficient management of public transport system and absence of pedestrian friendly facilities. The issue of constriction is addressed as lack of opportunity for horizontal expansion of the CBD due to its densely developed surrounding area. Similar issues were experienced...
Transportation Research Record: Journal of the Transportation Research Board, 2021
Stay-at-home policies in response to COVID-19 transformed high-volume arterials and highways into... more Stay-at-home policies in response to COVID-19 transformed high-volume arterials and highways into lower-volume roads, and reduced congestion during peak travel times. To learn from the effects of this transformation on traffic safety, an analysis of crash data in Ohio’s Franklin County, U.S., from February to May 2020 is presented, augmented by speed and network data. Crash characteristics such as type and time of day are analyzed during a period of stay-at-home guidelines, and two models are estimated: (i) a multinomial logistic regression that relates daily volume to crash severity; and (ii) a Bayesian hierarchical logistic regression model that relates increases in average road speeds to increased severity and the likelihood of a crash being fatal. The findings confirm that lower volumes are associated with higher severity. The opportunity of the pandemic response is taken to explore the mechanisms of this effect. It is shown that higher speeds were associated with more severe cr...
The COVID-19 pandemic has severely impacted public transit services through a combination of plum... more The COVID-19 pandemic has severely impacted public transit services through a combination of plummeting ridership during the lockdown and subsequent budget cuts. This study investigates the equity impacts of reductions in accessibility due to public transit service cuts during COVID-19 and their association with urban sprawl. We evaluated accessibility to essential services such as grocery stores and both urgent and non-urgent health care across 22 cities across the United States in three phases during 2020: pre-lockdown, lockdown, and post-lockdown. We estimated the spatio-temporal coverage of transit service during the peak and off-peak periods in each phase. We found stark disparities in food and health care access for various socio-economic groups. Economically disadvantaged and suburban neighborhoods were more likely to lose food and health care access by public transit during COVID-19. In particular, transit service cuts worsened accessibility for population groups with multip...
The COVID-19 pandemic has profoundly reshaped urban mobility. During the lockdown, workers telewo... more The COVID-19 pandemic has profoundly reshaped urban mobility. During the lockdown, workers teleworked if possible and left home only for essential activities. Our study investigates the spatial patterns of essential travel and their socio-economic differences during the COVID-19 lockdown phase in comparison with the same period in 2019. Using data from Columbus, Ohio, we categorized travelers into high, moderate, and low socio-economic status (SES) clusters and modeled travel demand of SES clusters for both phases using spatially weighted interaction models. Then, we characterized the SES variability in essential travel based on frequently visited business activities from each cluster. Results suggest that disparities in travel across SES clusters existed prior to COVID-19 are exacerbated during the pandemic lockdown. The diffused travel pattern of high and moderate SES cluster became localized while the pre-existing localized travel pattern of low SES cluster became diffused. Durin...
This repository provides the data used in the manuscript entitled "Reducing public transit c... more This repository provides the data used in the manuscript entitled "Reducing public transit compounds social vulnerabilities during COVID-19" by A Kar, AL Carrel, HJ Miller, and HTK Le.
Dhaka, the capital city of Bangladesh, is one of the fastest growing megacities in the world. Wit... more Dhaka, the capital city of Bangladesh, is one of the fastest growing megacities in the world. With the rapid growth of population and high urbanization rate, Dhaka is bound to expand the borders to accommodate the growing need of space. But this expansion is already taking its toll in the form of environmental degradation and social injustice hampering the geographical sustainability in the process. This study proposes a controlled and well-planned development in the eastern fringe of Dhaka City (comprising of Badda, Satarkul and Vatara) to meet up the challenge of future accommodation requirements. The area being geographically vulnerable with lots of agricultural lands, water bodies and retention ponds, the prime concern is to ensure the geographic sustainability of the area and use all the natural features as a vital tool in the process of development. As a planning technique, Land Readjustment Scheme is applied in this regard. This report contains all the measures and proposals regarding the natural features of the study area as well as the whole process of the development scheme including a financial proposal to recover the cost of the development to make this plan financially viable. Finally, the outcome of the study shows that it can be well implemented as all the objectives are fulfilled to the fullest.
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growth of population and high urbanization rate, Dhaka is bound to expand the borders to accommodate the
growing need of space. But this expansion is already taking its toll in the form of environmental degradation
and social injustice hampering the geographical sustainability in the process. This study proposes a controlled
and well-planned development in the eastern fringe of Dhaka City (comprising of Badda, Satarkul and Vatara)
to meet up the challenge of future accommodation requirements. The area being geographically vulnerable
with lots of agricultural lands, water bodies and retention ponds, the prime concern is to ensure the
geographic sustainability of the area and use all the natural features as a vital tool in the process of
development. As a planning technique, Land Readjustment Scheme is applied in this regard. This report
contains all the measures and proposals regarding the natural features of the study area as well as the whole
process of the development scheme including a financial proposal to recover the cost of the development to
make this plan financially viable. Finally, the outcome of the study shows that it can be well implemented as all
the objectives are fulfilled to the fullest.
growth of population and high urbanization rate, Dhaka is bound to expand the borders to accommodate the
growing need of space. But this expansion is already taking its toll in the form of environmental degradation
and social injustice hampering the geographical sustainability in the process. This study proposes a controlled
and well-planned development in the eastern fringe of Dhaka City (comprising of Badda, Satarkul and Vatara)
to meet up the challenge of future accommodation requirements. The area being geographically vulnerable
with lots of agricultural lands, water bodies and retention ponds, the prime concern is to ensure the
geographic sustainability of the area and use all the natural features as a vital tool in the process of
development. As a planning technique, Land Readjustment Scheme is applied in this regard. This report
contains all the measures and proposals regarding the natural features of the study area as well as the whole
process of the development scheme including a financial proposal to recover the cost of the development to
make this plan financially viable. Finally, the outcome of the study shows that it can be well implemented as all
the objectives are fulfilled to the fullest.