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• 1. [Article] Connecting People to Places: Spatiotemporal Analysis of Transit Supply Using Travel-Time Cubes

  Despite its importance, temporal measures of accessibility are rarely used in transit research or practice. This is primarily due to the inherent difficulty and complexity in computing time-based accessibility ...

  Citation × Citation Citation Abstract Copy Title: Connecting People to Places: Spatiotemporal Analysis of Transit Supply Using Travel-Time Cubes Author: Farber, Steven Year: 2016 Despite its importance, temporal measures of accessibility are rarely used in transit research or practice. This is primarily due to the inherent difficulty and complexity in computing time-based accessibility metrics. Estimating origin-to-destination travel times that include the “last mile” of travel between the transit network and actual start and endpoints of the trip is technically difficult. Not only do such estimations require multimodal network structures, they also require detailed knowledge of transit schedules and sophisticated algorithms for calculating shortest paths using such inputs. Recently, new standards for sharing transit schedules and geographic data, namely the General Transit Feed Specification (GTFS) have prompted innovations in the analysis of complex transit travel times using the Esri ArcGIS package with the Network Analyst extension. With continued development of the analytical capabilities of network analysis functionality, this project assesses spatiotemporal dynamics in transit supply through an investigation of scheduled travel time variability. This report consists of a collection of three stand-alone research papers. The first defines a new data object, the public transit travel time cube, and demonstrates its use in measuring changes in transit provision over time, changes in accessibility to jobs, and the impacts of bicycling on the last mile problem. The second paper consists of a study of temporal mismatch between observed travel patterns and the spatiotemporal patterns of transit supply in the Wasatch Front. The third paper expands the food desert literature by measuring temporal fluctuations in food accessibility over the course of a typical day, and examining the trends for disparities between socioeconomic subgroups. Our findings indicate that time-based measures of transit accessibility provide more nuanced abilities for us to understand how people are impacted by temporal variability in transit provision. Title: Connecting People to Places: Spatiotemporal Analysis of Transit Supply Using Travel-Time Cubes Author: Farber, Steven Year: 2016 Despite its importance, temporal measures of accessibility are rarely used in transit research or practice. This is primarily due to the inherent difficulty and complexity in computing time-based accessibility metrics. Estimating origin-to-destination travel times that include the “last mile” of travel between the transit network and actual start and endpoints of the trip is technically difficult. Not only do such estimations require multimodal network structures, they also require detailed knowledge of transit schedules and sophisticated algorithms for calculating shortest paths using such inputs. Recently, new standards for sharing transit schedules and geographic data, namely the General Transit Feed Specification (GTFS) have prompted innovations in the analysis of complex transit travel times using the Esri ArcGIS package with the Network Analyst extension. With continued development of the analytical capabilities of network analysis functionality, this project assesses spatiotemporal dynamics in transit supply through an investigation of scheduled travel time variability. This report consists of a collection of three stand-alone research papers. The first defines a new data object, the public transit travel time cube, and demonstrates its use in measuring changes in transit provision over time, changes in accessibility to jobs, and the impacts of bicycling on the last mile problem. The second paper consists of a study of temporal mismatch between observed travel patterns and the spatiotemporal patterns of transit supply in the Wasatch Front. The third paper expands the food desert literature by measuring temporal fluctuations in food accessibility over the course of a typical day, and examining the trends for disparities between socioeconomic subgroups. Our findings indicate that time-based measures of transit accessibility provide more nuanced abilities for us to understand how people are impacted by temporal variability in transit provision. Close

• 2. [Article] Assessing Transit Fare Equity in Utah Using a Geographic Information System

  The goal of this study is to develop and apply a new method for assessing social equity impacts of distance-based public transit fares. Shifting to a distance-based fare structure can disproportionately ...

  Citation × Citation Citation Abstract Copy Title: Assessing Transit Fare Equity in Utah Using a Geographic Information System Author: Farber, Steven, Batholomew, Keith, Li, Xiao, Paez, Antonio, Nurul Habib, Khandker M. Year: 2014 The goal of this study is to develop and apply a new method for assessing social equity impacts of distance-based public transit fares. Shifting to a distance-based fare structure can disproportionately favor or penalize different subgroups of a population based on variations in settlement patterns, travel needs, and most importantly, transit use. According to federal law, such disparities must be evaluated by the transit agency, but the area-based techniques identified by the Federal Transit Authority for assessing discrimination fail to account for disparities in distances travelled by transit users. This means that transit agencies currently lack guidelines for assessing the social equity impacts of replacing flat fare with distance-based fare structures. Our solution is to incorporate a joint ordinal-continuous model of trip generation and distance travelled into a GIS Decision Support System. The system enables a transit planner to visualize and compare estimated distances travelled and transit-cost maps for different population profiles and fare structures. We apply the method to a case study in the Wasatch Front, Utah, where the Utah Transit Authority is exploring a switch to a distance-based fare structure. The analysis reveals that overall distance-based fares benefit low-income, elderly, and non-white populations. However, the effect is geographically uneven, and may be negative for members of these groups living on the urban fringe. The research discusses a potential conflict between policies designed to promote equity and those intended to increase discretionary ridership. For example, increasing fares for longdistance discretionary riders travelling from suburban light-rail stations to the central business district may have a negative impact on ridership, despite being economically more efficient through cost-recapturing. At the same time, reducing fares for short-distance trips that are currently too expensive compared to private automobile travel may attract new riders. A full cost-benefit analysis sensitive to heterogeneous price elasticity is recommended for future research. It is also noted that the research findings are dependent on the current spatial distributions of population segments and travel patterns. The equity benefits of distance-based fares are primarily derived from residential clustering of low-income and minority groups in more compact urban areas near the center of the city. Demographic trends, such as inner-city gentrification and suburban aging-in-place, may impose increased travel demands on low income and elderly riders, nullifying future equity gains made by a transition to distance-based fares. Title: Assessing Transit Fare Equity in Utah Using a Geographic Information System Author: Farber, Steven, Batholomew, Keith, Li, Xiao, Paez, Antonio, Nurul Habib, Khandker M. Year: 2014 The goal of this study is to develop and apply a new method for assessing social equity impacts of distance-based public transit fares. Shifting to a distance-based fare structure can disproportionately favor or penalize different subgroups of a population based on variations in settlement patterns, travel needs, and most importantly, transit use. According to federal law, such disparities must be evaluated by the transit agency, but the area-based techniques identified by the Federal Transit Authority for assessing discrimination fail to account for disparities in distances travelled by transit users. This means that transit agencies currently lack guidelines for assessing the social equity impacts of replacing flat fare with distance-based fare structures. Our solution is to incorporate a joint ordinal-continuous model of trip generation and distance travelled into a GIS Decision Support System. The system enables a transit planner to visualize and compare estimated distances travelled and transit-cost maps for different population profiles and fare structures. We apply the method to a case study in the Wasatch Front, Utah, where the Utah Transit Authority is exploring a switch to a distance-based fare structure. The analysis reveals that overall distance-based fares benefit low-income, elderly, and non-white populations. However, the effect is geographically uneven, and may be negative for members of these groups living on the urban fringe. The research discusses a potential conflict between policies designed to promote equity and those intended to increase discretionary ridership. For example, increasing fares for longdistance discretionary riders travelling from suburban light-rail stations to the central business district may have a negative impact on ridership, despite being economically more efficient through cost-recapturing. At the same time, reducing fares for short-distance trips that are currently too expensive compared to private automobile travel may attract new riders. A full cost-benefit analysis sensitive to heterogeneous price elasticity is recommended for future research. It is also noted that the research findings are dependent on the current spatial distributions of population segments and travel patterns. The equity benefits of distance-based fares are primarily derived from residential clustering of low-income and minority groups in more compact urban areas near the center of the city. Demographic trends, such as inner-city gentrification and suburban aging-in-place, may impose increased travel demands on low income and elderly riders, nullifying future equity gains made by a transition to distance-based fares. Close