Sumeeta Srinivasan | Harvard University (original) (raw)

Papers by Sumeeta Srinivasan

For many countries like India the transport sector is the most rapidly growing energy end-use cat... more For many countries like India the transport sector is the most rapidly growing energy end-use category. Choices made now will have impacts lasting well into the middle of the 21st century. The desire for personal mobility in urban areas, typically by means of personal-use vehicles, will comprise much of growing transportation energy demand. Automobile emissions are the fastest increasing source of urban air pollution in most developing cities. In India most urban areas including Delhi already have major air pollution problems that could be greatly exacerbated if growth of the transport sector is managed unwisely. Delhi’s spatial growth over the last 25 years has been rapid and urban sprawl is contributing to increasing travel demand. We propose the development of decision support tools for understanding the different ways to manage this sprawl and plan for a better Delhi in years to come. This paper focuses on a vehicular air pollution information system, to provide some insight abo...

Urban Agriculture & Regional Food Systems, 2021

Public concern about the environmental consequences of our diets is growing and regional food sys... more Public concern about the environmental consequences of our diets is growing and regional food systems have emerged as one strategy to reduce these impacts. However, the potential environmental benefits of regional food systems are still largely untested and more empirical evidence is needed. Land and water are critical inputs to agriculture, but natural resource requirements and associated environmental impacts are highly dependent crop production location. This study used statistical analyses of crop yield and water footprint data to examine regional variability in land and water requirements and location‐specific tradeoffs between these resources. Regional land requirements and water requirements differed among most of the 17 fruit and vegetable crops we examined. Our results also showed inverse relationships between land and irrigation water requirements for eight crops, indicating that location‐specific tradeoffs between land and water resources exist for these crops. Understanding these regional differences and tradeoffs in natural resource requirements can help us evaluate the environmental implications of a more regionalized food system.

This report proposes a technique for estimating the spatial variation of average household vehicl... more This report proposes a technique for estimating the spatial variation of average household vehicle-miles traveled (VMT). The dependent variable, VMT, is estimated for block groups in the metropolitan regions of two cities - San Francisco, CA, and Boston, MA. The independent variables were obtained from the U.S. Census and include variables such as commute time to work and percentage of workers using public transit. Model-predicted values for zip-code-level VMT demonstrate a correlation coefficient of 0.90 with values imputed from Massachusetts state vehicle inspections data. These findings are proposed as evidence that "snap-shot" estimates of urban and regional variations in household VMT may be possible through the manipulation of freely available Census data. However, the results do indicate spatial autocorrelation and future estimates must take into account such spatial anomalies in estimating VMT.

Transportation Research Part D: Transport and Environment, 2020

Housing Policy Debate, 2020

Housing issues, including affordability, instability, and the search for available units, present... more Housing issues, including affordability, instability, and the search for available units, present ongoing challenges for urban inhabitants. Supporters claim information and communication technology (ICT) can solve housing problems through increased efficiency, transparency, and the creation of smart cities. However, little is known about the actual use and application of ICT data on housing issues. This article reviews and assesses recent empirical research involving housing and ICT data. Using Web of Science to identify relevant articles, we find most studies focus on housing search and prices or home sharing, which partly reflects the availability of data in these domains. Few articles use ICT data to explore housing challenges for economically vulnerable, historically disadvantaged, or marginalized groups. We discuss concerns about representation in ICT data related to housing and argue for more attention to the needs of vulnerable groups to help build more inclusive smart cities.

PLOS ONE, 2018

Background The purpose of this study was to determine the impact of prison release on HIV inciden... more Background The purpose of this study was to determine the impact of prison release on HIV incidence in the southern region of the United States, the region with the highest rates of both incarceration and new HIV diagnoses nationwide. Methods 5-year HIV diagnoses rates were calculated at the ZIP code level for nine cities and metropolitan statistical areas in the US South (ZIP codes, N = 600). Multilevel regression models were constructed and adjusted rate ratios (ARRs) were estimated for overall, male and female HIV diagnoses rates. Results Across the nine cities, in multilevel, multivariate analysis, controlling for income inequality (GINI coefficient), percent living in poverty and percent Non-Hispanic Black population, the ZIP code level overall HIV diagnosis rate was significantly associated with prison release [ARR 1.004 (95%CI 1.0007, 1.006), p<0.01]. A 10-person increase in prison release rate would result in a 4% increase in overall 5-year HIV diagnosis rate-approximately 9.4 additional cases per 100,000 population. In gender-stratified models, prison release rate was significantly associated with the ZIP code level HIV diagnosis rate for males [ARR 1.004 (95%CI 1.0004, 1.007), p<0.01], but not for females. Conclusions In the southern region of the US, prison release is significantly associated with HIV incidence. HIV prevention interventions should promote timely linkage to ongoing treatment for released inmates living with HIV.

International Journal of Sustainable Transportation, 2019

In this paper, we look at differences in travel behavior and location characteristics across inco... more In this paper, we look at differences in travel behavior and location characteristics across income in Chengdu, China at two points of time, 2005 and 2016, using household travel surveys. Specifically, we compare changes over time for different income groups for Chengdu in 2005 and 2016. We find that walking or biking remains the most common mode for all income groups but higher-income households appear to have more choices depending on the proximity of their neighborhood to downtown. We also find that both average local and average regional access have worsened since 2005. Furthermore, it appears that there is less economic diversity within neighborhoods in 2016 when compared to 2005, with more locations appearing to have 40% or more of low-, middle-, or high-income households than in the past. Finally, we find that lowincome households and older trip makers are more likely to walk or bike and that high-income households are the most likely to own cars and use motorized modes. Built environment characteristics like mixed land use appear to significantly reduce travel time in 2016 but do not result in higher non-motorized transport mode share. We contribute to existing literature by evaluating changes in the relationship of built environment and travel behavior during a period of rapid urbanization and economic growth in a Chinese city.

Transportation Research Part D: Transport and Environment, 2019

Developing less auto-dependent urban forms and promoting low-carbon transportation (LCT) are chal... more Developing less auto-dependent urban forms and promoting low-carbon transportation (LCT) are challenges facing our cities. Previous literature has supported the association between neighborhood form and low-carbon travel behaviour. Several studies have attempted to measure neighborhood forms focusing on physical built-environment factors such as population and employment density and socioeconomic conditions such as income and race. We find that these characteristics may not be sufficiently fine-grained to differentiate between neighborhoods in Chinese cities. This research assesses characteristics of neighborhood spatial configuration that may influence the choice of LCT modes in the context of dense Chinese cities. Urban-form data from 40 neighborhoods in Chengdu, China, along with a travel behaviour survey of households conducted in 2016, were used to generate several measures of land use diversity and accessibility for each neighborhood. We use principle component analysis (PCA) to group these variables into dimensions that could be used to classify the neighborhoods. We then estimate regression models of low-carbon mode choices such as walking, bicycling, and transit to better understand the significance of these built-environment differences at the neighbourhood level. We find that, first, members of households do choose to walk or bike or take transit to work provided there is relatively high population density and sufficient access to public transit and jobs. Second, landuse diversity alone was not found to be significant in affecting LCT mode choice. Third, the proliferation of gated communities was found to reduce overall spatial connectivity within neighborhoods and had a negative effect on choice of LCT. 1. Introduction: Travel behavior and urban form Sustainable urban form and built environment that encourages low-carbon travel are urgently needed to respond to environmental crises of climate change and degradation of air quality associated with urbanization (The World Bank, 2010). Travel-induced emissions include both greenhouse gases (GHGs) that contribute to climate change, notably CO 2 , and air pollutants that degrade urban air quality, notably NO X and primary PM 2.5 (Chen et al., 2018). (In this paper "low-carbon" is shorthand for low emissions not only of CO 2 but also local air pollutants, as all are derived primarily from combustion of carbon-based fuels.) Promoting LCT, including walking, bicycling, and the usage of public transit, by improving the design of neighborhoods can reduce the per capita carbon footprint of city dwellers (Liu et al, 2017).

Handbook of Research on Emerging Innovations in Rail Transportation Engineering

The city of Chennai has made road accident data available with the address location of road accid... more The city of Chennai has made road accident data available with the address location of road accidents and the total numbers of persons and pedestrians affected in the accident in 2009. These data were geocoded to locate the accidents with respect to the census wards within the Chennai Corporation area. Both the total number of persons as well as pedestrians in accidents as well as the rate of accidents normalized by population in the ward were modeled as dependent variables using Poisson based regression models to see the effect of location characteristics such as road length, vehicle traffic, proximity to existing and proposed transit infrastructure and the percentage of the land developed between 1991-2009. The results from the models suggest that location does indeed affect the risk for accidents in Chennai and that planners in the city may need to better understand the implications of roads, urban development, transit access and the built environment for traffic safety.

Encyclopedia of GIS, 2015

Open Forum Infectious Diseases, 2016

Transportation Research Record Journal of the Transportation Research Board, 2010

Encyclopedia of GIS, 2008

Urban Studies, 2002

Land-use initiatives represent a potentially effective tool for coping with the kinds of mobility... more Land-use initiatives represent a potentially effective tool for coping with the kinds of mobility pattern that North American cities faced in the 1990s and still face in the present century. As fine-grained data about land use and travel activity become available, they provide the opportunity to improve our understanding of the linkage between land use and transport. This paper examines in detail the neighbourhood characteristics that could affect mode choice on the work and non-work tour. Neighbourhood characteristics include land use, network and accessibility-related characteristics which are quantified through the use of geographical information systems (GIS). Ultimately, such measures could be used in conjunction with detailed surveys of travel behaviour to specify, calibrate and use models of modal choice and residential choice that are more sensitive to the fine-grained spatial structure of neighbourhoods and transport corridors in metropolitan areas. Micro-level data for the...

Transportation Research Record: Journal of the Transportation Research Board, 2001

Land use initiatives represent a potentially effective tool for coping with the kinds of mobility... more Land use initiatives represent a potentially effective tool for coping with the kinds of mobility patterns that North American cities face in the 1990s and in the coming century. As fine-grained data about land use and travel activity become available, they provide the opportunity to improve the understanding of the linkage between land use and transportation. The neighborhood characteristics that could affect travel behavior on the non-work tour are examined in detail. Neighborhood characteristics include land use, network, and accessibility-related characteristics quantified through the use of a geographic information system. Ultimately, such measures could be used in conjunction with detailed surveys of travel behavior to specify, calibrate, and use models of modal choice and trip type that are more sensitive to the fine-grained spatial structure of neighborhoods and transportation corridors in metropolitan areas. Microlevel data for the Boston metropolitan area, together with a ...

Transportation Research Part D: Transport and Environment, 2002

Previous work with data from the Boston Metropolitan Area has suggested that land use characteris... more Previous work with data from the Boston Metropolitan Area has suggested that land use characteristics can have measurable impacts on travel behavior such as trip linking and mode choice at the individual level. However, trip planning, especially in households with children or more ...

Computers, Environment and Urban Systems, 1996

ABSTRACT Planners often work with data consisting of attributes attached to areal units or points... more ABSTRACT Planners often work with data consisting of attributes attached to areal units or points in space, but in this disaggregated form interpretation is not easy. In this paper, we describe a computer-based tool planners can use to graphically aggregate data by delineating areas that include data points characterized by similar values of certain attributes. First, we discuss the need for this tool and the conceptual issues underlying it. Then, we describe the tool itself: which uses GIS (Geographic Information System) software as a data-management and visualization tool and to build a user interface. Finally, we describe how the tool was used to analyze data derived from a study of unregulated housing in the city of Ahmedabad, India. The map representations generated by the tool showed clearly the trends in the spatial location of informal housing, and therefore simplified the task of policy analysis because it made clear which factors related to the spatial distribution of such housing.

Transportation Research Record: Journal of the Transportation Research Board

Thousands of communities across America now promote walking and biking (active commuting) to scho... more Thousands of communities across America now promote walking and biking (active commuting) to school as a mechanism to increase physical activity, reduce traffic congestion, and improve air quality. Distance to school and attributes of the built environment are crucial factors in a child’s mode choice, and some of the most difficult determinants to influence with programmatic interventions. Further understanding the built environment’s role may help in assessing a school’s mode shift potential and more effectively planning and implementing strategies that increase walking and biking to school. Based on a student travel behavior survey of 18,713 responses from 105 schools in Massachusetts, a multilevel model was used to investigate the effects of route, neighborhood, and school characteristics on walking to school. The model results indicate that the built environment affects the odds of walking to school. Specifically, short routes along less-trafficked streets with mixed land use ar...

Habitat International, 2016