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• 1. [Article] Understanding Transportation in Urban China - Local Residents vs Migrant Workers

  With rapid urbanization in China and other developing economies around the world, it has become imperative to understand household transportation behavior and expenditures in these urban areas. The objective ...

  Citation × Citation Citation Abstract Copy Title: Understanding Transportation in Urban China - Local Residents vs Migrant Workers Author: Liu, Jenny H. Year: 2016 With rapid urbanization in China and other developing economies around the world, it has become imperative to understand household transportation behavior and expenditures in these urban areas. The objective of this study is to examine the differences in the determinants of household transportation expenditures within two very distinct populations in Chinese cities: local residents and migrant workers. In order to craft policies or strategies promoting sustainable transportation or livability, it is essential to understand whether the drivers that push the migrant population towards spending more on transportation or owning bikes or motorbikes are similar to drivers for the rest of the population. This is further complicated by the differential treatment of households within China’s hukou (household registration) system which determines eligibility to receive public benefits in housing or education. Because nearly 40% of the population in urban areas are migrants, it is particularly important to examine how the transportation choices and behavior of migrant households may diverge (or not) from the rest of the urban dwellers. Utilizing a unique dataset that surveys both types of households, we utilize descriptive statistics and regression models to analyze their transportation expenditures. We find that household income level and automobile ownership are the strongest predictors of household transportation expenditures. In addition, larger local resident households who are younger tend to spend more on transportation while migrant households generally spend less on transportation, particularly those with stronger social networks and those who do not hold urban hukou status. We conclude that significant differences do exist and may be exacerbated by inequitable access to public services, housing opportunities and other urban amenities in addition to major differences in household composition, preferences and levels of participation in the urban economic and social systems. Title: Understanding Transportation in Urban China - Local Residents vs Migrant Workers Author: Liu, Jenny H. Year: 2016 With rapid urbanization in China and other developing economies around the world, it has become imperative to understand household transportation behavior and expenditures in these urban areas. The objective of this study is to examine the differences in the determinants of household transportation expenditures within two very distinct populations in Chinese cities: local residents and migrant workers. In order to craft policies or strategies promoting sustainable transportation or livability, it is essential to understand whether the drivers that push the migrant population towards spending more on transportation or owning bikes or motorbikes are similar to drivers for the rest of the population. This is further complicated by the differential treatment of households within China’s hukou (household registration) system which determines eligibility to receive public benefits in housing or education. Because nearly 40% of the population in urban areas are migrants, it is particularly important to examine how the transportation choices and behavior of migrant households may diverge (or not) from the rest of the urban dwellers. Utilizing a unique dataset that surveys both types of households, we utilize descriptive statistics and regression models to analyze their transportation expenditures. We find that household income level and automobile ownership are the strongest predictors of household transportation expenditures. In addition, larger local resident households who are younger tend to spend more on transportation while migrant households generally spend less on transportation, particularly those with stronger social networks and those who do not hold urban hukou status. We conclude that significant differences do exist and may be exacerbated by inequitable access to public services, housing opportunities and other urban amenities in addition to major differences in household composition, preferences and levels of participation in the urban economic and social systems. Close

• 2. [Article] The Trade-offs between Population Density and Households' Transportation-housing Costs

  As metropolitan area governments and others promote density-promoting “smart growth” policies, finer analysis is needed to quantify the impact of such policies on households' transportation and housing ...

  Citation × Citation Citation Abstract Copy Title: The Trade-offs between Population Density and Households' Transportation-housing Costs Author: Wang, Haizhong Year: 2015 As metropolitan area governments and others promote density-promoting “smart growth” policies, finer analysis is needed to quantify the impact of such policies on households' transportation and housing costs. Existing research suggests that households in urban areas trade-off between housing costs and transportation costs, but does not explore how policies to increase urban densities might explicitly impact this balance. Furthermore, the research does not adequately distinguish between the effect of urban area density and the effects of other factors associated with urban area density (e.g metropolitan area size and household incomes) on housing costs. This research uses the 2000 Census Public Use Micro Sample (PUMS) person and household data from 23 of the nation's most densely populated states to identify the impact of increased population density on three housing cost measures: household rents, housing unit values, and monthly mortgage payments. Log linear models were estimated for each housing cost measure using least-squares regression. Dependent variables included household, housing unit, and geographic area characteristics, including population density. The models were found to be very similar to one another in terms of the statistical significance and values of estimated model parameters. Population density (measured at the PUMS area level) was found to be statistically significant at the 0.01 level for all housing cost measures. Although significant, the parameter estimates show that the elasticity of housing cost with respect to population density is low, ranging from 0.041 to 0.05. This research also explores the relationship between housing costs and accessibility. Results show that households living in areas closer to jobs (as indicated by shorter average commute times) and households utilizing fixed route transit systems have marginally higher housing costs. Title: The Trade-offs between Population Density and Households' Transportation-housing Costs Author: Wang, Haizhong Year: 2015 As metropolitan area governments and others promote density-promoting “smart growth” policies, finer analysis is needed to quantify the impact of such policies on households' transportation and housing costs. Existing research suggests that households in urban areas trade-off between housing costs and transportation costs, but does not explore how policies to increase urban densities might explicitly impact this balance. Furthermore, the research does not adequately distinguish between the effect of urban area density and the effects of other factors associated with urban area density (e.g metropolitan area size and household incomes) on housing costs. This research uses the 2000 Census Public Use Micro Sample (PUMS) person and household data from 23 of the nation's most densely populated states to identify the impact of increased population density on three housing cost measures: household rents, housing unit values, and monthly mortgage payments. Log linear models were estimated for each housing cost measure using least-squares regression. Dependent variables included household, housing unit, and geographic area characteristics, including population density. The models were found to be very similar to one another in terms of the statistical significance and values of estimated model parameters. Population density (measured at the PUMS area level) was found to be statistically significant at the 0.01 level for all housing cost measures. Although significant, the parameter estimates show that the elasticity of housing cost with respect to population density is low, ranging from 0.041 to 0.05. This research also explores the relationship between housing costs and accessibility. Results show that households living in areas closer to jobs (as indicated by shorter average commute times) and households utilizing fixed route transit systems have marginally higher housing costs. Close

• 3. [Article] Edged Out: Location Efficient Housing and Low Income Households in the Portland Region

  Transportation costs are typically a household’s second largest expense after housing. Low income households are especially burdened by transportation costs, with low income households spending up to two ...

  Citation × Citation Citation Abstract Copy Title: Edged Out: Location Efficient Housing and Low Income Households in the Portland Region Author: Tremoulet, Andrée, Dann, Ryan Year: 2016 Transportation costs are typically a household’s second largest expense after housing. Low income households are especially burdened by transportation costs, with low income households spending up to two times as much of their income on transportation than higher income households (Litman, 2013). Thus, access to location efficient housing is especially important to low income households, including those who use a housing voucher to help pay for housing costs. This seminar presents the results of a two-year project supported by the Portland region's four public housing authorities to design and test tools to help people with housing vouchers find location efficient housing. We examine the challenges that residents faced and discuss policy implications. Title: Edged Out: Location Efficient Housing and Low Income Households in the Portland Region Author: Tremoulet, Andrée, Dann, Ryan Year: 2016 Transportation costs are typically a household’s second largest expense after housing. Low income households are especially burdened by transportation costs, with low income households spending up to two times as much of their income on transportation than higher income households (Litman, 2013). Thus, access to location efficient housing is especially important to low income households, including those who use a housing voucher to help pay for housing costs. This seminar presents the results of a two-year project supported by the Portland region's four public housing authorities to design and test tools to help people with housing vouchers find location efficient housing. We examine the challenges that residents faced and discuss policy implications. Close

• 4. [Article] Tools for Assisting Low-Income Households with Finding Location-Efficient Housing

  Through a previously funded research project, Encouraging Low-Income Households to Make Location-Efficient Housing Choices, our team developed a toolkit to assist households utilizing Section 8 Housing ...

  Citation × Citation Citation Abstract Copy Title: Tools for Assisting Low-Income Households with Finding Location-Efficient Housing Author: Tremoulet, Andrée Year: 2016 Through a previously funded research project, Encouraging Low-Income Households to Make Location-Efficient Housing Choices, our team developed a toolkit to assist households utilizing Section 8 Housing Choice Vouchers with finding location-efficient/affordable housing. These tools are currently in use by the region’s four public housing authorities (PHAs). This technology transfer project provided the tools to social service providers who work with voucher recipients in the Portland region and provided a presentation on research findings and policy implications to transportation researchers, professionals and students. Specific activities included: • In-person presentations to groups of social service providers in three counties (four presentations total) who provide case management and other intensive social services for households with low incomes. • A TREC-sponsored presentation/webinar as part of the TREC Friday Transportation Seminar series In addition, final edits were completed on a manuscript included in Housing Policy Debate’s special issue on location-affordable housing. Additional research was begun on a manuscript for submission to the Transportation Research Board. Title: Tools for Assisting Low-Income Households with Finding Location-Efficient Housing Author: Tremoulet, Andrée Year: 2016 Through a previously funded research project, Encouraging Low-Income Households to Make Location-Efficient Housing Choices, our team developed a toolkit to assist households utilizing Section 8 Housing Choice Vouchers with finding location-efficient/affordable housing. These tools are currently in use by the region’s four public housing authorities (PHAs). This technology transfer project provided the tools to social service providers who work with voucher recipients in the Portland region and provided a presentation on research findings and policy implications to transportation researchers, professionals and students. Specific activities included: • In-person presentations to groups of social service providers in three counties (four presentations total) who provide case management and other intensive social services for households with low incomes. • A TREC-sponsored presentation/webinar as part of the TREC Friday Transportation Seminar series In addition, final edits were completed on a manuscript included in Housing Policy Debate’s special issue on location-affordable housing. Additional research was begun on a manuscript for submission to the Transportation Research Board. Close

• 5. [Article] The Importance of Housing, Accessibility, and Transport Characteristic Ratings on Stated Neighborhood Preference

  Travel demand models commonly lack the ability to understand how changing residential preferences influence future housing, land use, and transportation policies. As communities struggle to address social ...

  Citation × Citation Citation Abstract Copy Title: The Importance of Housing, Accessibility, and Transport Characteristic Ratings on Stated Neighborhood Preference Author: Currans, Kristina Marie Year: 2016 Travel demand models commonly lack the ability to understand how changing residential preferences influence future housing, land use, and transportation policies. As communities struggle to address social challenges related to increased economic uncertainty, transportation and land use planning have become increasingly centered on assumptions concerning the market for residential environments and travel choices. In response, an added importance has been placed on the development of toolkits capable of providing robust and flexible models to aid in understanding how differing assumptions contribute to a set of planning scenarios and how future residential location decisions may be made. In this study, we aim to examine the ability for current land use and transportation models to adequately account for the mechanism that drive households to prefer different neighborhoods based on typical transportation modeling methods. In particular, we conduct an original stated preference survey to identify the characteristics and preferences of individuals and households that influence unconstrained residential neighborhood preferences. Our objectives are to (a) determine the key drivers of residential neighborhood preferences, (b) test the contribution of sociodemographic and economic household characteristics commonly used in regional modeling tools to allocate households regionally across neighborhoods (e.g. household size, income, age, tenure), and (c) identify the preference profiles that can improve the sensitivity of our regional and statewide transportation-land use models to residential neighborhood preferences. The presentation for this seminar was done jointly with Steven Gehrke. It can be accessed at http://archives.pdx.edu/ds/psu/18234. Title: The Importance of Housing, Accessibility, and Transport Characteristic Ratings on Stated Neighborhood Preference Author: Currans, Kristina Marie Year: 2016 Travel demand models commonly lack the ability to understand how changing residential preferences influence future housing, land use, and transportation policies. As communities struggle to address social challenges related to increased economic uncertainty, transportation and land use planning have become increasingly centered on assumptions concerning the market for residential environments and travel choices. In response, an added importance has been placed on the development of toolkits capable of providing robust and flexible models to aid in understanding how differing assumptions contribute to a set of planning scenarios and how future residential location decisions may be made. In this study, we aim to examine the ability for current land use and transportation models to adequately account for the mechanism that drive households to prefer different neighborhoods based on typical transportation modeling methods. In particular, we conduct an original stated preference survey to identify the characteristics and preferences of individuals and households that influence unconstrained residential neighborhood preferences. Our objectives are to (a) determine the key drivers of residential neighborhood preferences, (b) test the contribution of sociodemographic and economic household characteristics commonly used in regional modeling tools to allocate households regionally across neighborhoods (e.g. household size, income, age, tenure), and (c) identify the preference profiles that can improve the sensitivity of our regional and statewide transportation-land use models to residential neighborhood preferences. The presentation for this seminar was done jointly with Steven Gehrke. It can be accessed at http://archives.pdx.edu/ds/psu/18234. Close

• 6. [Article] How Does Transportation Affordability Vary Among TODs, TADs, and Other Areas?

  Transit-oriented development (TOD) has gained popularity worldwide as a sustainable form of urbanism; it concentrates development near a transit station so as to reduce auto-dependency and increase ridership. ...

  Citation × Citation Citation Abstract Copy Title: How Does Transportation Affordability Vary Among TODs, TADs, and Other Areas? Author: Scheer, Brenda, Ewing, Reid, Park, Keunhyun, Khan, Shabnam Sifat Ara Year: 2017 Transit-oriented development (TOD) has gained popularity worldwide as a sustainable form of urbanism; it concentrates development near a transit station so as to reduce auto-dependency and increase ridership. Existing travel behavior studies in the context of TOD, however, are limited in terms of small sample size, inconsistent TOD classification methods, and failure to control for residential self-selection. Thus, this study has three research questions. First, how can we distinguish between Transit-oriented development (TOD) and Transit-adjacent development (TAD)? Second, how do travel behaviors vary between TODs and TADs? Third, how does transportation affordability vary between TODs and TADs? This study utilizes cluster analysis to classify station area types and propensity score matching to control residential self-selection. From cluster analysis with built-environment factors—density, diversity, and walkability—in a half-mile buffer, this study classifies existing station areas as TOD, TAD or Hybrid types. After controlling for residential self-selection, it shows that a TOD motivates its residents to walk more and take transit more while using personal vehicles less. The significant difference between TOD and TAD in both VMT and the number of auto trips demonstrates that TODs make the personal vehicle trips shorter and fewer. Travel behavior in the Hybrid type demonstrates the possibility of gradual and practical change. Finally, the percentage of household income spent on transportation is lower in TOD households than TAD households. This shows that a TOD household is likely to save enough money on vehicle ownership and use that, while it likely spends more on transit, the final result is a significantly lower financial burden from transportation. Title: How Does Transportation Affordability Vary Among TODs, TADs, and Other Areas? Author: Scheer, Brenda, Ewing, Reid, Park, Keunhyun, Khan, Shabnam Sifat Ara Year: 2017 Transit-oriented development (TOD) has gained popularity worldwide as a sustainable form of urbanism; it concentrates development near a transit station so as to reduce auto-dependency and increase ridership. Existing travel behavior studies in the context of TOD, however, are limited in terms of small sample size, inconsistent TOD classification methods, and failure to control for residential self-selection. Thus, this study has three research questions. First, how can we distinguish between Transit-oriented development (TOD) and Transit-adjacent development (TAD)? Second, how do travel behaviors vary between TODs and TADs? Third, how does transportation affordability vary between TODs and TADs? This study utilizes cluster analysis to classify station area types and propensity score matching to control residential self-selection. From cluster analysis with built-environment factors—density, diversity, and walkability—in a half-mile buffer, this study classifies existing station areas as TOD, TAD or Hybrid types. After controlling for residential self-selection, it shows that a TOD motivates its residents to walk more and take transit more while using personal vehicles less. The significant difference between TOD and TAD in both VMT and the number of auto trips demonstrates that TODs make the personal vehicle trips shorter and fewer. Travel behavior in the Hybrid type demonstrates the possibility of gradual and practical change. Finally, the percentage of household income spent on transportation is lower in TOD households than TAD households. This shows that a TOD household is likely to save enough money on vehicle ownership and use that, while it likely spends more on transit, the final result is a significantly lower financial burden from transportation. Close

• 7. [Article] Cycling by Choice or Necessity? Exploring the Gender Gap in Bicycling in Oregon

  In Oregon, as elsewhere in the US, a greater percentage of men bicycle than women. This study illuminates the gender gap in bicycling by exploring differences in bicycling among women and men in Oregon. ...

  Citation × Citation Citation Abstract Copy Title: Cycling by Choice or Necessity? Exploring the Gender Gap in Bicycling in Oregon Author: Singleton, Patrick Allen Year: 2016 In Oregon, as elsewhere in the US, a greater percentage of men bicycle than women. This study illuminates the gender gap in bicycling by exploring differences in bicycling among women and men in Oregon. A one-day statewide travel survey of over 30,000 adults was examined. Comparisons between individual, household, and trip and activity characteristics for people grouped by gender (women vs. men) and bicycling (made a bicycle trip or normally commuted by bicycle vs. did not bicycle) were assessed using chi-squared tests of independence. Many significant differences were found. In particular, women living alone, not working, without a high-school degree, without a driver license, and living in low-income households or zero-vehicle households were less likely to bicycle than other women. Men with similar characteristics did not exhibit the same trends and sometimes were even more likely to bicycle. These findings are consistent with a perspective that women who bicycle are more likely to do so by choice, whereas women with fewer means are less likely to turn to bicycling than their male counterparts. In addition, there was partial support for the idea that women’s roles and responsibilities (for household maintenance and escorting, but not necessarily the presence of children) may contribute to this deficit. The study’s results begin to suggest a rethinking of bicycle-promoting policies and interventions to better target certain women, although further research is needed to more fully understand bicycling’s gender gap. Title: Cycling by Choice or Necessity? Exploring the Gender Gap in Bicycling in Oregon Author: Singleton, Patrick Allen Year: 2016 In Oregon, as elsewhere in the US, a greater percentage of men bicycle than women. This study illuminates the gender gap in bicycling by exploring differences in bicycling among women and men in Oregon. A one-day statewide travel survey of over 30,000 adults was examined. Comparisons between individual, household, and trip and activity characteristics for people grouped by gender (women vs. men) and bicycling (made a bicycle trip or normally commuted by bicycle vs. did not bicycle) were assessed using chi-squared tests of independence. Many significant differences were found. In particular, women living alone, not working, without a high-school degree, without a driver license, and living in low-income households or zero-vehicle households were less likely to bicycle than other women. Men with similar characteristics did not exhibit the same trends and sometimes were even more likely to bicycle. These findings are consistent with a perspective that women who bicycle are more likely to do so by choice, whereas women with fewer means are less likely to turn to bicycling than their male counterparts. In addition, there was partial support for the idea that women’s roles and responsibilities (for household maintenance and escorting, but not necessarily the presence of children) may contribute to this deficit. The study’s results begin to suggest a rethinking of bicycle-promoting policies and interventions to better target certain women, although further research is needed to more fully understand bicycling’s gender gap. Close

• 8. [Article] When Cities Shrink, Affordability Does Too

  To better understand the real costs of housing and transportation in a declining urban context, NITC researchers implemented a household survey to determine whether the assumptions made in existing research ...

  Citation × Citation Citation Abstract Copy Title: When Cities Shrink, Affordability Does Too Author: Ganning, Joanna, Tighe, Jenna Rosie Year: 2017 To better understand the real costs of housing and transportation in a declining urban context, NITC researchers implemented a household survey to determine whether the assumptions made in existing research literature and in the LAI regarding household expenditures and transportation accessibility hold true when analyzing shrinking cities—generally, cities characterized by a long-term loss in occupied housing units. The project was led by Joanna Ganning of Cleveland State University, who has conducted previous research into shrinking cities with the support of the NITC program. Title: When Cities Shrink, Affordability Does Too Author: Ganning, Joanna, Tighe, Jenna Rosie Year: 2017 To better understand the real costs of housing and transportation in a declining urban context, NITC researchers implemented a household survey to determine whether the assumptions made in existing research literature and in the LAI regarding household expenditures and transportation accessibility hold true when analyzing shrinking cities—generally, cities characterized by a long-term loss in occupied housing units. The project was led by Joanna Ganning of Cleveland State University, who has conducted previous research into shrinking cities with the support of the NITC program. Close

• 9. [Article] What Do We Know About Location Affordability in U.S. Shrinking Cities?

  In late 2013, the Department of Housing and Urban Development (HUD) launched the Location Affordability Index (LAI) portal. Their dataset uses models to estimate typical amount households spend on housing ...

  Citation × Citation Citation Abstract Copy Title: What Do We Know About Location Affordability in U.S. Shrinking Cities? Author: Ganning, Joanna, Tighe, Jenna Rosie Year: 2017 In late 2013, the Department of Housing and Urban Development (HUD) launched the Location Affordability Index (LAI) portal. Their dataset uses models to estimate typical amount households spend on housing and transportation at the block group level, and calculates “H + T Affordability,” the percent of household income spent on these items. In our previous research, we analyzed 81 shrinking cities to determine how location affordability differs across various neighborhoods. Our results suggest that households in declining neighborhoods, as compared to stable or redeveloping neighborhoods, face the greatest H + T affordability challenges in shrinking cities. Furthermore, in declining neighborhoods, virtually all of the additional affordability challenges encountered can be accounted for by differences in transportation affordability rather than housing. Since there is virtually no research to either validate or suggest bias in the LAI data, and a declining neighborhood in a shrinking city presents both a relatively common yet entirely dissimilar context to the norm, we feel that this data should be carefully calibrated to, and tested for, this setting to ensure that appropriate and efficient policy follow. In this report, we present the results of two research phases: a strictly quantitative first stage in which the LAI is disassembled and reassembled, taking stock of assumptions, methods, and accuracy. This work finds that the LAI generally over-estimates housing costs, but more for renters and more in metropolitan areas. Estimations of transportation cost burdens are built largely from unreliable data and using models which cannot be replicated, leading us to conclude that these cost burden estimates may not be reliable. In the second research phase, which is survey-based, we gather household-level data from 12 Census tracts in Cleveland, Ohio, to estimate household housing and transportation costs and cost burdens and gain a clearer sense of budget trade-offs where costs are unaffordable. The survey results support the first research stage. The LAI over-estimates housing costs for these neighborhoods by approximately 17% and transportation costs by approximately 126%, meaning the LAI estimates for transportation are not reliable. By and large, households trade essentials, investing, and paying bills (at all or in full) to cover their costs in housing and transportation. Title: What Do We Know About Location Affordability in U.S. Shrinking Cities? Author: Ganning, Joanna, Tighe, Jenna Rosie Year: 2017 In late 2013, the Department of Housing and Urban Development (HUD) launched the Location Affordability Index (LAI) portal. Their dataset uses models to estimate typical amount households spend on housing and transportation at the block group level, and calculates “H + T Affordability,” the percent of household income spent on these items. In our previous research, we analyzed 81 shrinking cities to determine how location affordability differs across various neighborhoods. Our results suggest that households in declining neighborhoods, as compared to stable or redeveloping neighborhoods, face the greatest H + T affordability challenges in shrinking cities. Furthermore, in declining neighborhoods, virtually all of the additional affordability challenges encountered can be accounted for by differences in transportation affordability rather than housing. Since there is virtually no research to either validate or suggest bias in the LAI data, and a declining neighborhood in a shrinking city presents both a relatively common yet entirely dissimilar context to the norm, we feel that this data should be carefully calibrated to, and tested for, this setting to ensure that appropriate and efficient policy follow. In this report, we present the results of two research phases: a strictly quantitative first stage in which the LAI is disassembled and reassembled, taking stock of assumptions, methods, and accuracy. This work finds that the LAI generally over-estimates housing costs, but more for renters and more in metropolitan areas. Estimations of transportation cost burdens are built largely from unreliable data and using models which cannot be replicated, leading us to conclude that these cost burden estimates may not be reliable. In the second research phase, which is survey-based, we gather household-level data from 12 Census tracts in Cleveland, Ohio, to estimate household housing and transportation costs and cost burdens and gain a clearer sense of budget trade-offs where costs are unaffordable. The survey results support the first research stage. The LAI over-estimates housing costs for these neighborhoods by approximately 17% and transportation costs by approximately 126%, meaning the LAI estimates for transportation are not reliable. By and large, households trade essentials, investing, and paying bills (at all or in full) to cover their costs in housing and transportation. Close

• 10. [Article] Wider Dissemination of Household Travel Survey Data Using Geographical Perturbation Methods

  Public agencies spend vast amounts of money collecting information about passenger travel in household travel surveys. These data are valuable for the rich and detailed information they provide, which ...

  Citation × Citation Citation Abstract Copy Title: Wider Dissemination of Household Travel Survey Data Using Geographical Perturbation Methods Author: Clifton, Kelly J., Gehrke, Steven R. Year: 2014 Public agencies spend vast amounts of money collecting information about passenger travel in household travel surveys. These data are valuable for the rich and detailed information they provide, which contribute to regional and statewide travel demand models. These data have utility beyond travel demand modeling in their application to transportation policy and travel behavior research. As the demand on these data increase, so have the quantity of information collected. Detailed geospatial referencing of the home, work and other travel destinations are common practice and permit the integration with other spatially archived data sources, such as land use characteristics, transportation system information, and other built environment, social and economic data. Other public agencies, private consultancies, non-profits and educational institutions may benefit from access to the original data with applications to areas such public health, equity, transportation safety and urban planning. Oregon Modeling Collaborative (OMC) has entered into an agreement with Oregon Modeling Steering Committee (OMSC) to host and make available Oregon Household Activity Survey (OHAS) datasets. But wide distribution of these important and expensive data is limited by the requirement to protect the confidentiality of survey participants, who are guaranteed anonymity in exchange for participation. Data are often aggregated to a geographic level such as Census tracts or transportation analysis zones (TAZs) before disseminating to the public, which limits the utility of this information. This project aims to develop a methodology to permit dissemination of these spatially-explicit data to a wider range of public constituents while at the same time, protecting the identities of study participants. Making use of these data, this project will use geographical perturbation methods to add noise to the original data to protect confidentiality while at the same time allowing the detailed geo-spatial referencing to be included in the disseminated data. The process includes: The coordinates (locations) will be geographically perturbed (masked) so that they do not reveal the identity of the traveler while at the same time retaining spatial relevance and resolution. Here the limits of the perturbation (minimum and maximum displacement) need to be determined that a) ensure confidentiality and b) minimize the errors introduced to the data. The original and perturbed (masked) data will be compared using various statistical approaches to develop a set of confidence measures for different types of transportation applications. For example, geographically perturbed (masked) may be more robust for automobile travel measures, such as vehicle miles traveled (VMT) or transit accessibility than for detailed pedestrian or bicycle trip attributes. This exercise will allow spatially-explicit OHAS data to be released to the public with some information about the confidence to which it can be applied. These data will be archived at Portland State University and made available to the public. The information and algorithms can be shared with other agencies collecting and archiving travel data, such as the National Household Travel Survey, metropolitan planning organizations and state departments of transportation, to permit wider dissemination of their data. Title: Wider Dissemination of Household Travel Survey Data Using Geographical Perturbation Methods Author: Clifton, Kelly J., Gehrke, Steven R. Year: 2014 Public agencies spend vast amounts of money collecting information about passenger travel in household travel surveys. These data are valuable for the rich and detailed information they provide, which contribute to regional and statewide travel demand models. These data have utility beyond travel demand modeling in their application to transportation policy and travel behavior research. As the demand on these data increase, so have the quantity of information collected. Detailed geospatial referencing of the home, work and other travel destinations are common practice and permit the integration with other spatially archived data sources, such as land use characteristics, transportation system information, and other built environment, social and economic data. Other public agencies, private consultancies, non-profits and educational institutions may benefit from access to the original data with applications to areas such public health, equity, transportation safety and urban planning. Oregon Modeling Collaborative (OMC) has entered into an agreement with Oregon Modeling Steering Committee (OMSC) to host and make available Oregon Household Activity Survey (OHAS) datasets. But wide distribution of these important and expensive data is limited by the requirement to protect the confidentiality of survey participants, who are guaranteed anonymity in exchange for participation. Data are often aggregated to a geographic level such as Census tracts or transportation analysis zones (TAZs) before disseminating to the public, which limits the utility of this information. This project aims to develop a methodology to permit dissemination of these spatially-explicit data to a wider range of public constituents while at the same time, protecting the identities of study participants. Making use of these data, this project will use geographical perturbation methods to add noise to the original data to protect confidentiality while at the same time allowing the detailed geo-spatial referencing to be included in the disseminated data. The process includes: The coordinates (locations) will be geographically perturbed (masked) so that they do not reveal the identity of the traveler while at the same time retaining spatial relevance and resolution. Here the limits of the perturbation (minimum and maximum displacement) need to be determined that a) ensure confidentiality and b) minimize the errors introduced to the data. The original and perturbed (masked) data will be compared using various statistical approaches to develop a set of confidence measures for different types of transportation applications. For example, geographically perturbed (masked) may be more robust for automobile travel measures, such as vehicle miles traveled (VMT) or transit accessibility than for detailed pedestrian or bicycle trip attributes. This exercise will allow spatially-explicit OHAS data to be released to the public with some information about the confidence to which it can be applied. These data will be archived at Portland State University and made available to the public. The information and algorithms can be shared with other agencies collecting and archiving travel data, such as the National Household Travel Survey, metropolitan planning organizations and state departments of transportation, to permit wider dissemination of their data. Close