Archives: Research Products

policy brief

Shared Autonomous Mobility Services Show Promise for Increasing Access to Employment in Southern California

Publication Date

May 1, 2020

Associated Project

Author(s)

Arash Ghaffar, Michael Hyland, Navjyoth Sarma, Suman Mitra, Tanjeeb Ahmed

Areas of Expertise

Intelligent Transportation Systems, Emerging Technologies, & Big Data Safety, Public Health, & Mobility Justice
View policy brief

Abstract

Workers in Southern California currently face transportation related challenges accessing employment opportunities, including but not limited to high parking costs and/or limited parking availability in dense employment and residential areas; long commute distances between residential areas and employment opportunities; and poor transit service quality in many areas. These challenges are particularly burdensome for low-income households that may not have access to a personal vehicle and/or live in job-poor neighborhoods, as having a personal vehicle may be the only viable way to get to work.

Suggested Citation
Arash Ghaffar, Michael Hyland, Navjyoth Sarma, Suman Mitra and Tanjeeb Ahmed (2020) Shared Autonomous Mobility Services Show Promise for Increasing Access to Employment in Southern California. Policy Brief. UC ITS. Available at: https://doi.org/10.7922/g24f1p14.

Related Publications

published journal article | Nov 2020

Quantifying the employment accessibility benefits of shared automated vehicle mobility services: Consumer welfare approach using logsums
Transportation Research Part A: Policy and Practice

research report | Feb 2020

Assessment of the Employment Accessibility Benefits of Shared Autonomous Mobility Services

working paper

The Impacts of Motor Vehicle Operation on Water Quality: A Preliminary Assessment

Publication Date

September 1, 2003

Author(s)

Hilary Nixon, Jean-Daniel Saphores

Areas of Expertise

Infrastructure Delivery, Operations, & Resilience Zero-Emission Vehicles & Low-Carbon Fuels
View working paper

Abstract

Environmental studies of motor vehicles typically focus on air pollution or noise, but ignore water pollution. In this paper, we examine some of the impacts of motor vehicle transportation on non-point source and on groundwater pollution. Our estimates of the present value of costs for cleaning up leaking underground storage tanks and for controlling highway runoff for major arterials range from $45 billion to $235 billion, which is at least as much as noise damages. Our review of applicable measures suggests that effective policies should combine economic incentives, information campaigns, and enforcement measures, coupled with preventive environmental measures.

conference paper

How do they get by without cars in california?: Travel characteristics of voluntarily and involuntarily carless households

Proceedings of the 98th annual meeting of the transportation research board

Publication Date

January 1, 2019

Author(s)

Suman Mitra, Jean-Daniel Saphores

Abstract

In spite of their increasing number in the U.S., our understanding of the travel behavior of households who do not own motor vehicles (labeled â??carlessâ?? herein) is sketchy. The goal of this paper is to start filling this gap for California. The authors perform parametric and non-parametric tests to analyze trip data from the 2012 California Household Travel Survey (CHTS) after classifying carless households as voluntarily carless, involuntarily carless, or unclassifiable based on a CHTS question that inquires why a carless household does not own any motor vehicle. The authors find substantial differences between voluntarily and involuntarily carless households. Compared to their voluntarily carless peers, involuntarily carless households travel less frequently, their trips are longer and they take more time, partly because their environment is not as well adapted to their needs. They also walk/bike less, depend more on transit, and when they travel by motor vehicle, occupancy is typically higher. Their median travel time is also longer, but remarkably, it is similar for voluntarily carless and motorized households. Overall, involuntarily carless households are less mobile, which may contribute to a more isolated lifestyle with a lower degree of well-being. Compared to motorized households, carless households rely a lot less on motor vehicles and much more on transit, walking, and biking. They also take less than half as many trips and their median trip distance is less than half as short. This study is a first step toward better understanding the transportation patterns of carless households.

Suggested Citation
Suman K. Mitra and Jean-Daniel M. Saphores (2019) “How do they get by without cars in california?: Travel characteristics of voluntarily and involuntarily carless households”, in Proceedings of the 98th annual meeting of the transportation research board, p. 7p.

conference paper

MitM attack by name collision: Cause analysis and vulnerability assessment in the new gTLD era

2016 IEEE symposium on security and privacy (SP)

Publication Date

May 1, 2016

Author(s)

Qi Alfred Chen, Eric Osterweil, Matthew Thomas, Z. Morley Mao
View conference paper
Suggested Citation
Qi Alfred Chen, Eric Osterweil, Matthew Thomas and Z. Morley Mao (2016) “MitM attack by name collision: Cause analysis and vulnerability assessment in the new gTLD era”, in 2016 IEEE symposium on security and privacy (SP). IEEE, pp. 675–690. Available at: 10.1109/sp.2016.46.

policy brief

A Review of Reduced and Free Transit Fare Programs in California

Publication Date

May 1, 2020

Associated Project

Author(s)

Jean-Daniel Saphores

Policy Brief

UC-ITS-2019-55-pb

Areas of Expertise

Public Transit, Shared Mobility, & Active Transportation
View policy brief

Abstract

Free or reduced-fare transit passes have the potential to increase transit ridership, enhance the mobility of underserved groups (e.g., low-income, seniors, and youth), and reduce the environmental footprint of transportation. Under the right conditions, these programs can also help reduce traffic congestion and motor vehicle use. Transit agencies in different parts of the world have been experimenting with free or reduced-fare transit for decades, yet there are still substantial concerns about the impacts of free or reduced-fare transit on ridership as well as on the fiscal health of transit agencies. Some of these concerns linger partly because rigorous academic studies on free and reduced-fare transit passes are still rare.

Suggested Citation
Jean-Daniel Saphores (2020) A Review of Reduced and Free Transit Fare Programs in California. Policy Brief UC-ITS-2019-55-pb. UC ITS. Available at: https://doi.org/10.7922/g2fj2f4s.

Related Publications

research report | Jan 2020

A Review of Reduced and Free Transit Fare Programs in California

published journal article

Employer-paid parking, mode choice, and suburbanization

Journal of Urban Economics

Publication Date

March 1, 2018

Author(s)

Jan Brueckner, Sofia Franco
View published journal article
Suggested Citation
Jan K. Brueckner and Sofia F. Franco (2018) “Employer-paid parking, mode choice, and suburbanization”, Journal of Urban Economics, 104, pp. 35–46. Available at: 10.1016/j.jue.2017.12.002.

published journal article

Evaluation of effectiveness of automated work zone information systems

Transportation Research Record

Publication Date

January 1, 2005

Author(s)

Lianyu Chu, Hee-Kyung Kim, Younshik Chung, Will Recker
View published journal article
Suggested Citation
Lianyu Chu, Hee-Kyung Kim, Younshik Chung and Will Recker (2005) “Evaluation of effectiveness of automated work zone information systems”, Transportation Research Record, 1911(1), pp. 73–81. Available at: 10.1177/0361198105191100108.

conference paper

Distributed approach to network-wide traffic control management

Proceedings of the international conference on applications of advanced technologies in transportation engineering

Publication Date

January 1, 1998

Author(s)

Filippo Logi, Stephen Ritchie
Suggested Citation
Filippo Logi and Stephen G. Ritchie (1998) “Distributed approach to network-wide traffic control management”, in Proceedings of the international conference on applications of advanced technologies in transportation engineering, pp. 83–90.

book/book chapter

The Impacts of Bus Use on COVID-19 Dispersion

Publication Date

January 1, 2023

Associated Project

Author(s)

Henry Bernal, David Brownstone

Areas of Expertise

Public Transit, Shared Mobility, & Active Transportation Safety, Public Health, & Mobility Justice
View book/book chapter

Abstract

This research examines how bus use impacts the transmission of the COVID-19 virus in urban areas, focusing on the evolution of the COVID-19 pandemic in Los Angeles County. Using data from the Los Angeles County Metropolitan Transportation Authority on station-level ridership in October 2019, April 2020, and October 2020, we impute station-level ridership for other months in our data and map these to 231 Countywide Statistical Areas (CSAs) in Los Angeles County, which are used by the Los Angeles Department of Public Health to report community COVID-19 transmission. We obtain CSA-specific COVID-19 case counts between March 16, 2020 and January 31, 2021 to create a monthly panel of bus ridership and COVID-19 cases. After using a dynamic panel regression, our findings provide no evidence that increased ridership levels or trip lengths are associated with higher incidence of COVID-19 at the CSA level in Los Angeles County in the period between June 2020 and January 2021.

Suggested Citation
Henry Bernal and David Brownstone (2023) “The Impacts of Bus Use on COVID-19 Dispersion”, in A. Loukaitou-Sideris, A.M. Bayen, G. Circellaand R. Jayakrishnan (eds.) Pandemic in the Metropolis: Transportation Impacts and Recovery. Cham: Springer International Publishing (Springer Tracts on Transportation and Traffic), pp. 233–249. Available at: 10.1007/978-3-031-00148-2_15.

Related Publications

policy brief | Apr 2021

Higher Bus Ridership Unlikely to Increase Community COVID-19 Transmission

conference paper

Integrated mode choice and dynamic traveler assignment-simulation framework to assess the impact of a suburban first-mile shared autonomous vehicle fleet service on transit demand

Proceedings of the 97th annual meeting of the transportation research board

Publication Date

January 1, 2018

Author(s)

Helen Karla Ramalho de Farias Pinto, Michael Hyland, Ä° Ã?mer Verbas, Hani Mahmassani

Abstract

The emergence and adoption of fully-autonomous vehicles (AVs) and AV-enabled mobility services are expected to significantly impact transit demand in urban and suburban areas. This paper focuses on assessing the impact of a suburban first-mile shared-ride AV (SAV) transit feeder system on transit and SAV demand. To complete this task, the authors introduce an integrated mode choice and dynamic traveler assignment-simulation modeling framework that explicitly models the dynamics of, and congestion in, the transit network and SAV system. First, the authors present a mathematical formulation of the integrated mode choice and dynamic traveler assignment problem. The problem is analytically intractable; therefore, the authors present a simulation-based, iterative, bi-level solution approach. The iterative bi-level solution approach is required because the modal flows are dependent on the transit, road, and SAV system performances; yet, these system performances are dependent on the modal flows. In the iterative modeling framework, the upper level assigns travelers to one of five modes: car, park-and-ride, transit, SAV, or transit with SAV feeder. The lower level, both (1) iteratively determines minimum cost transit hyperpaths, assigns travelers to hyperpaths, and simulates their experiences, and (2) simulates an SAV fleet providing service to suburban travelers. Time-dependent network performance skims are then fed to the mode choice model. This process repeats until the mode choice probabilities converge. This integrated modeling framework, which endogenously determines traveler mode choice as well as transit and SAV system performance, provides transportation planners and modelers a powerful tool to test various scenarios related to AV-enabled mobility services.

Suggested Citation
Helen Karla Ramalho de Farias Pinto, Michael F. Hyland, Ä° Ã?mer Verbas and Hani S. Mahmassani (2018) “Integrated mode choice and dynamic traveler assignment-simulation framework to assess the impact of a suburban first-mile shared autonomous vehicle fleet service on transit demand”, in Proceedings of the 97th annual meeting of the transportation research board, p. 9p.

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