published journal article

Gender differences in elderly mobility in the United States

Transportation Research Part A: Policy and Practice

Abstract

Mobility is a critical element of one’s quality of life regardless of one’s age. Although the challenges for women are more significant than those for men as they age, far less is known about the gender differences in mobility patterns of older adults, especially in the United States (US) context. This paper reports on a study that examined potential gender gaps in mobility patterns of older adults (aged 65 years and over) in the US by analyzing data from the 2017 National Household Travel Survey. Elderly respondents were first classified into one of six clusters based on socio-demographic variables. A Structural Equation Model (SEM) was then estimated and showed that gender gaps existed in the mobility patterns of the elderly, and the differences were diverse across the different clusters. The most substantial gender gap was found in the Senior Elder with Medical Condition(s) cluster, followed by the High-income Workers cluster and the Middle-income Urban Residents cluster. In contrast, females in the Low-Income Single Elder cluster enjoyed statistically significant positive mobility differences with their male counterparts. Our results also found that female elderly in the Senior Elder with Medical Condition(s) and the Low-income Family Elder clusters suffered most after the cessation of driving, with the largest mobility gender gap in the Middle-income Urban Resident cluster. This study will help transportation planners and policymakers understand gender and other socio-demographic differences in elderly mobility. Thus, it will facilitate the development of measures to improve elderly mobility and reduce gender gaps by recognizing and addressing specific target groups’ mobility characteristics and needs rather than treating the elderly as a single potential user group.

Suggested Citation
Suman Mitra, Mingqi Yao and Stephen G. Ritchie (2021) “Gender differences in elderly mobility in the United States”, Transportation Research Part A: Policy and Practice, 154, pp. 203–226. Available at: 10.1016/j.tra.2021.10.015.

working paper

Efficient Estimation of Nested Logit Models

Publication Date

June 1, 1985

Working Paper

UCI-ITS-WP-85-4

Areas of Expertise

Abstract

This paper examines the Sequential, Full Information Maximum Likelihood (FIML), and Linearized Maximum Likelihood (LML) estimators for a Nested Logit model of time-of-day choice for work trips. These estimators are compared using a Monte Carlo study based on specification and data from a previously published empirical study. The sequential estimator is found to be much less efficient than either LML or FIML; and its uncorrected second-stage standard-error estimates are strongly downward biased. LML is only slightly less efficient than FIML, but is often easier to compute. However there are cases where the sequential and LML estimators do not exist.

Suggested Citation
David Brownstone and Kenneth A. Small (1985) Efficient Estimation of Nested Logit Models. Working Paper UCI-ITS-WP-85-4. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/7017v80x.

working paper

Is Jobs-Housing Balance a Transportation Issue?

Publication Date

October 30, 1991

Associated Project

Abstract

Jobs-housing balance has become a major planning and public policy issue. Despite its popularity and apparent acceptance among public policy makers as a solution for traffic congestion and air pollution problems, there is little consensus on what jobs-housing balance means and little evidence that a jobs-housing balance policy would have any significant effect on these problems. The jobs-housing balance policy is premised on the idea that job and housing location choices are closely linked, and that policy intervention is required to achieve a balance of housing and jobs. Existing evidence suggests that the relationship between where people choose to live and work is complex, and may have little to do with job access considerations. Further, patterns of urban growth and travel indicate that balancing occurs as part of the urban development process. It is concluded that jobs-housing balance is not an effective solution for traffic congestion and air pollution concerns. Rather, these problems are better addressed in a more direct way.

Suggested Citation
Genevieve Giuliano (1991) Is Jobs-Housing Balance a Transportation Issue?. Working Paper Reprint No. 133. Institute of Transportation Studies, UC Irvine: University of California Transportation Center. Available at: https://escholarship.org/uc/item/4874r4hg.

Phd Dissertation

Activity-based travel analysis in the wireless information age

Suggested Citation
JAMES E. MARCA (2002) Activity-based travel analysis in the wireless information age. PhD Dissertation. UC Irvine. Available at: https://uci.primo.exlibrisgroup.com/permalink/01CDL_IRV_INST/17uq3m8/alma991008196379704701.

working paper

Standard Transportation Forecasting Techniques: How They Fail

Publication Date

September 1, 1984

Working Paper

UCI-ITS-WP-84-5

Areas of Expertise

Abstract

The decade of the 1980s is proving to be a critical one for transportation system choices. Our transportation infrastructure is on the verge of collapse in many areas. Boston’s rail system. New York’s subway. Connecticut’s highway bridges. and aging urban freeways in the nation’s major cities. are all in dire need of rehabilitation. At the same time. funds are being solicited for new projects. most of which have been on the drawing board for more than a decade. These include interstate highway projects. as well as rail transit projects in major cities throughout the country. In view of the massive investment our current “wish list” of projects implies. it is appropriate to examine the justification for these investments and the way we forecast the need for them.

Suggested Citation
Genevieve Giuliano (1984) Standard Transportation Forecasting Techniques: How They Fail. Working Paper UCI-ITS-WP-84-5. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/32w6b00q.

Phd Dissertation

Modeling individual route choice with automated real -time vehicle trip histories

Abstract

Collecting rich individual trip data at an individual level has long been viewed as a hard task and has become a bottleneck in modeling and calibrating travel behavior models since traditional survey methods are both costly and time-consuming. New technologies make such data a possibility and thus there is a need for frameworks that model individual behavior in real-time using such data. Such modeling will find use in a variety of real-time network optimization and prediction schemes. This dissertation describes the details of plausible behavioral modeling of this kind, and develops new data structures that are needed both for handling the network combinatorics in the analysis and in the data storage. The work is presented in the context of a new technology we propose called the Persistent Traffic Cookie (PTC) system which uses the short range wireless connection between vehicles and road side controllers to store authenticated, time-stamped node sequences on an onboard database. The dissertation makes the premise that traditional travel behavior models, including those based on disaggregate decision paradigms were developed primarily for application in aggregate level prediction and are thus not very applicable for an individual’s route choice prediction in real-time. A scheme that does not require variation of explanatory variables across the choice sets or variation in the individual’s decisions for calibration may be essential. Thus the dissertation developed models based on observed frequencies of decisions. The research also stresses the importance of path and sub-path notions in route choice decisions and provides appropriate data structures that enable modeling with such notions. Two methods that directly query the collected sequence data using efficient data structures based on the suffix tree and the suffix array schemes and node/edge transition probability model, are proposed to predict individual travels from trip diary database. A day-to-day PTC simulation framework with behavior components is proposed to generate consistent PTC data and implemented in Paramics microscopic traffic simulator. Day-to-day PTC simulations are carried out for two Paramics networks, including the Irvine Triangle network, which is a well-calibrated real world network. Various scenarios are created to test the sensitivities of the proposed prediction methods. The simulation results shows that it seems the prediction methods are robust with regard to the underlying behavior models, traffic conditions and tracking periods.

Suggested Citation
Yu Zhang (2006) Modeling individual route choice with automated real -time vehicle trip histories. Ph.D.. University of California, Irvine. Available at: https://uci.primo.exlibrisgroup.com/permalink/01CDL_IRV_INST/1gpb62p/alma991035092986404701 (Accessed: October 14, 2023).

working paper

A Survey and Analysis of Energy Intensity Estimates for Urban Transportation Modes

Abstract

The current interest in energy conservation has resulted in a spate of divergent estimates of the energy intensiveness (EI) of urban transit modes. This paper critically reviews the methodologies and data sources employed by these estimates. It is shown that a very small repertory of sources and methodologies underlie the EI estimates, and that variance among them is primarily attributable to contradictory load factor assumptions. El estimates for bus and rail transit are developed, and the inadequacies of automobile data are discussed. Buses are shown to be more efficient than rail transit, and it is shown that light rail’s energy advantage over heavy rail lies in construction, not operation.

Suggested Citation
Kenneth M. Chomitz (1978) A Survey and Analysis of Energy Intensity Estimates for Urban Transportation Modes. Working Paper UCI-ITS-WP-78-14. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/5577d1gr.

Phd Dissertation

Walking and urban form: Modeling and testing parental decisions about children's travel

Abstract

Over the past several years, the private vehicle has become the predominant mode of travel to school while walking and bicycling rates have decreased. Some suggest that this change in travel behavior contributes to negative health outcomes in children, including increased rates of (1) overweight/obesity through inactivity and (2) pedestrian and bicyclist fatality and injury. A series of recent policies and programs directly attribute the change in travel behavior to school to the urban form of communities. Limited research exists to support this hypothesis, however. The fundamental questions of whether and how urban form impacts a child’s trip to school must to be answered in order to develop effective interventions aimed at increasing rates of walking and bicycling activity and safety. This research proposes a conceptual framework to examine the nature and shape of the relationships between urban form; interpersonal, demographic and social/cultural factors; parental decision-making and a child’s travel to school. Using parent survey data on children’s travel to school and urban design assessments from twelve elementary school neighborhoods, the relative influence of urban form on the mode choice to school was first determined. Results indicate that urban form elements such as street lights and street widths do affect the probability of a child walking or bicycling to school; however, the affect of these elements is modest compared to other influential variables such as the perceived convenience of driving, country of birth, family support of walking behavior, reported traffic conditions in the neighborhood and perceived distances between home and school. A second analysis examined how urban form and children’s travel behavior relate by testing the hypothesis of an indirect relationship. The findings show that parent’s feelings of neighborhood safety, traffic safety and/or household transportation options do not intervene in the relationship between urban form and children’s travel behavior. Socio-demographic characteristics and parent’s attitudes toward travel, however, may modify the strength of the relationship between urban form and children’s travel behavior. The results of this study advance the discussion on relationships between urban form, transportation and health and inform policy and practice of the best targets for future planning interventions.

Suggested Citation
Tracey Elizabeth McMillan (2003) Walking and urban form: Modeling and testing parental decisions about children's travel. PhD Dissertation. UC Irvine. Available at: https://uci.primo.exlibrisgroup.com/permalink/01CDL_IRV_INST/17uq3m8/alma991035093496804701.

working paper

Automobile Driving and Aggressive Behavior: Effects of Multiple Disinhibitory Influences

Publication Date

April 1, 1988

Author(s)

Working Paper

UCI-ITS-WP-88-4

Areas of Expertise

Abstract

Automobiles and aggressive behavior have an extensive association, ranging from themes of dominance and territoriality to flagrant assaultive actions. A broad range of aggressive behaviors in the context of driving can be understood in terms of the disinhibition of aggression through multiple influence channels. The paper discusses the disinhibitory factors of physiological arousal, traffic context, cognitive scripts, and contagion mechanisms. Some results of two preliminary surveys concerning roadway aggression (victimization and perpetration) are presented which suggest that such occurrences are more prevalent than commonly acknowledged. 

Suggested Citation
Raymond W. Novaco (1988) Automobile Driving and Aggressive Behavior: Effects of Multiple Disinhibitory Influences. Working Paper UCI-ITS-WP-88-4. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/2sn3r2t4.

published journal article

Improving community resilience to disrupted food access: Empirical spatio-temporal analysis of volunteer-based crowdsourced food delivery

Journal of Transport Geography

Publication Date

December 1, 2024

Author(s)

Gretchen Bella, Elisa Borowski, Amanda Stathopoulos

Abstract

Unplanned disaster events can greatly disrupt access to essential resources, with calamitous outcomes for already vulnerable households. This is particularly challenging when concurrent extreme events affect both the ability of households to travel and the functioning of traditional transportation networks that supply resources. This paper examines the use of volunteer-based crowdsourced food delivery as a community resilience tactic to improve food accessibility during overlapping disruptions with lasting effects, such as the COVID-19 pandemic and climate disasters. The study uses large-scale spatio-temporal data (n = 28,512) on crowdsourced food deliveries in Houston, TX, spanning from 2020 through 2022, merged with data on community demographics and significant disruptive events occurring in the two-year timespan. Three research lenses are applied to understand the effectiveness of crowdsourced food delivery programs for food access recovery: 1) geographic analysis illustrates hot spots of demand and impacts of disasters on requests for food assistance within the study area; 2) linear spatio-temporal modeling identifies a distinction between shelter-in-place emergencies and evacuation emergencies regarding demand for food assistance; 3) structural equation modeling identifies socially vulnerable identity clusters that impact requests for food assistance. The findings from the study suggest that volunteer-based crowdsourced food delivery adds to the resilience of food insecure communities, supporting its effectiveness in serving its intended populations. The paper contributes to the literature by illustrating how resilience is a function of time and space, and that similarly, there is value in a dynamic representation of community vulnerability. The results point to a new approach to resource recovery following disaster events by shifting the burden of transportation from resource-seekers and traditional transportation systems to home delivery by a crowdsourced volunteer network.

Suggested Citation
Gretchen Bella, Elisa Borowski and Amanda Stathopoulos (2024) “Improving community resilience to disrupted food access: Empirical spatio-temporal analysis of volunteer-based crowdsourced food delivery”, Journal of Transport Geography, 121, p. 104018. Available at: 10.1016/j.jtrangeo.2024.104018.