Skip to content
The Institute of Transportation Studies at UC Irvine
  • About
    • Leadership
    • Affiliated Centers
    • IT Resources
    • ITS-Irvine Policies
    • Contact
  • Research
    • Areas of Expertise
    • Publications
    • Projects
    • Requests for Proposals
    • TRIP Program
    • PRIME Program
  • Education
  • People
    • Researchers
    • Administrative Staff
    • Current Students
    • PhD Graduates
    • Past Faculty Associates
  • News & Events
    • News
    • Events
  • About
    • Leadership
    • Affiliated Centers
    • IT Resources
    • ITS-Irvine Policies
    • Contact
  • Research
    • Areas of Expertise
    • Publications
    • Projects
    • Requests for Proposals
    • TRIP Program
    • PRIME Program
  • Education
  • People
    • Researchers
    • Administrative Staff
    • Current Students
    • PhD Graduates
    • Past Faculty Associates
  • News & Events
    • News
    • Events

Sponsor: RIMI

Changing Transit Ridership and Service During the COVID-19 Pandemic

Status

Complete

Project Timeline

March 1, 2022 - June 30, 2023

Principal Investigator

Michael HylandMichael Hyland

Sponsor, Program & Award Number

RIMI: RIMI-4H

Areas of Expertise

Public Transit, Shared Mobility, & Active Transportation

Team Departmental Affiliation

Civil and Environmental Engineering

Project Summary

The COVID-19 pandemic spurred a period of significant change in travel behavior in the United States. Increased working from home, teleconferencing, telelearning, and e-commerce changed how travelers perceive, interact with, and use public transportation and shared mobility. According to the Federal Transit Administration, at the start of the pandemic public transit ridership in the U.S. dropped by 79% between 2019 and 2020. While some riders have returned, public transit ridership remains below pre-pandemic levels. Transit operators may be serving different needs, as post-pandemic travel behavior and the use of other forms of shared mobility (such as microtransit and transportation network companies) continues to evolve. Public transit operators have also been impacted by new pandemic-related procedures, service cuts, and staffing shortages. This project will explore how the pandemic impacted public transportation and shared mobility to inform policy recommendations that can help the state maximize the effectiveness of shared and active transportation options. It will examine the current state of public transit, how transit agencies can evolve into this new context, and how other shared modes have been impacted by the pandemic. The project will also assess how micromobility (both personally owned and shared) can fill gaps in public transit networks caused by California’s changed post-pandemic travel demand. It will also examine the role that active transportation infrastructure can play in improving safety and environmental outcomes, enhancing social equity, and economic development in a variety of built environments.

Policy Brief Series on the Role of Hydrogen in California’s Transportation System

Status

Complete

Project Timeline

March 1, 2022 - June 30, 2023

Principal Investigator

Scott Samuelsen

Project Team

Jeff Reed

Sponsor, Program & Award Number

RIMI: RIMI-3N

Areas of Expertise

Zero-Emission Vehicles & Low-Carbon Fuels

Team Departmental Affiliation

Mechanical and Aerospace Engineering

Project Summary

Currently, hydrogen is used in California in only a few significant applications, with refining being the most dominant. However, hydrogen has the potential to be a major zero-carbon energy carrier across many applications, including transportation. California’s current suite of policies supporting decarbonization tend to be technology neutral, which may not provide sufficient incentives for the hydrogen market to develop in a timely and optimal way. This series of policy briefs investigates the role of hydrogen in decarbonizing the transportation sector and other sectors in California. Collectively, the briefs provide an overview of i) how hydrogen could be used, and how much end-use demand potential there could be for different applications across transportation, buildings and industry; ii) the relative carbon intensity of hydrogen production pathways and the availability of biomass and biogas in California that could be applied to the production of low-CI hydrogen; and iii) the current costs of producing green hydrogen and how much green hydrogen could potentially be produced.

Related Publications

policy brief | Sep 2022

Can Green Hydrogen Be a Cost Competitive Transportation Fuel by 2030?

Read more
policy brief | Sep 2022

Potential Uses of Hydrogen in California’s Clean Energy Transition

Read more
policy brief | Sep 2022

Hydrogen Can Have a Much Lower Carbon Intensity than Fossil Fuels But This Largely Depends on How It Is Produced and Distributed

Read more

Pilot Study: Demonstrate Real-World Security Threats to Connected Automated Vehicles

Status

In Progress

Project Timeline

July 22, 2022 - June 30, 2023

Principal Investigator

Qi Alfred Chen

Project Team

Ningfei Wang

Sponsor, Program & Award Number

RIMI: RIMI-5G
(Also see the UC ITS page)

Areas of Expertise

Intelligent Transportation Systems, Emerging Technologies, & Big Data

Team Departmental Affiliation

Information and Computer Science

Project Summary

While connected and automated vehicles (CAVs) have the potential to transform communities and mobility, issues like security threats – which may compromise infrastructure operations or even pose safety risks to road users – present significant challenges to the real-world deployment and operation of such systems. This project will explore and demonstrate the real-world feasibility and exploitability of existing CAV security threats that have emerged from academic research. The project will help stakeholders understand how realistic such threats are in practice, thereby informing policymaking, risk management, and remediation strategy planning.

Enhanced Perception with Cooperation between Connected Automated Vehicles and Smart Infrastructure

Status

Complete

Project Timeline

September 2, 2022 - June 30, 2023

Principal Investigator

Qi Alfred Chen

Project Team

Yunpeng Luo

Sponsor, Program & Award Number

RIMI: RIMI-5H
(Also see the UC ITS page)

Areas of Expertise

Infrastructure Delivery, Operations, & Resilience Intelligent Transportation Systems, Emerging Technologies, & Big Data

Team Departmental Affiliation

Information and Computer Science

Project Summary

Technological and infrastructure solutions will be needed to facilitate the safe integration of connected and automated vehicles (CAVs) into the national highway systems. Smart infrastructure is one possible solution that utilizes advanced sensing, computing, and communication capabilities, particularly at key highway bottlenecks and safety hotspots. The proposed pilot project, Smart Infrastructure for Automated driving (SIA), will demonstrate how advanced infrastructure data can support operations of connected and automated driving systems and understand various practical challenges, such as system underperformance due to factors including, but not limited to, communication delays, sensor malfunction, and cyberattacks.

Related Publications

policy brief | Feb 2025

How Cooperation Between Connected Automated Vehicles and Smart Infrastructure Can Improve Situational Awareness for Traffic Safety

Read more
research report | Jan 2024

Enhanced perception with cooperation between connected automated vehicles and smart infrastructure.

Read more
presentation | Jun 2023

Pilot Study: Smart Infrastructure for Automated Driving

Read more

Assessing the Potential for Densification and Reduction of Vehicle Miles Traveled in Areas Without Rail

Status

Complete

Project Timeline

June 21, 2022 - October 31, 2023

Principal Investigator

Jae Hong Kim

Project Team

Doug Houston, Nicholas Marantz, Alex Okashita, Maxwell Cabello

Sponsor, Program & Award Number

RIMI: RIMI-4M

Areas of Expertise

Public Transit, Shared Mobility, & Active Transportation Travel Behavior, Land Use, & the Built Environment

Team Departmental Affiliation

Urban Planning and Public Policy

Project Summary

While transportation infrastructure and efficiency should inform where to build more housing, little is known about how housing allocation and development processes can be coordinated more systematically with transportation. To date, transportation-housing coordination has often relied on the densification of areas near rail transit stations, putting heavy burdens on these locations and their residents. Much less attention has been paid to how densification can be achieved in a more equitable manner by encompassing other sites. This research seeks to better understand equity issues and other challenges that may arise in pursuing transportation-informed densification. The research includes two components: 1) a scenario analysis of the potential impacts of SB 743 that highlights equity concerns, as well as difficulties in identifying low vehicle miles traveled locations, and 2) a qualitative, in-depth investigation, including interviews with policy experts, creators, implementers, and advocates that explore ways to achieve more inclusive densification of non-rail transit areas, which have long been neglected in the literature. Overall, the findings suggest that transportation-informed densification is a challenging process, and this is particularly true when it comes to implementation and inclusive place-making. More needs to be known about how densification can take place in a way that promotes diversity, equity, and inclusion rather than causing disproportionate impacts on disadvantaged communities and their residents.

Related Publications

research report | Sep 2024

Assessing the Potential for Densification and VMT Reduction in Areas without Rail Transit Access

Read more
policy brief | Sep 2024

What Challenges Can Arise from Coordinating Housing Development with Transportation?

Read more

How Shared Mobility Can Complement or Compete with Transit

Status

Complete

Project Timeline

June 27, 2022 - October 31, 2023

Principal Investigator

Michael HylandMichael Hyland

Sponsor, Program & Award Number

RIMI: RIMI-4B

Areas of Expertise

Public Transit, Shared Mobility, & Active Transportation

Team Departmental Affiliation

Civil and Environmental Engineering

Project Summary

While the COVID-19 pandemic caused ridership on public transit and shared mobility to drop precipitously and put severe strain on their finances and operations, all was far from well prior to the pandemic. Transit ridership had dropped across the state in the five years prior to the pandemic, despite increasing public investment. Furthermore, the relationship between shared mobility and public transit was often disputed, with some stakeholders claiming they complement each other and others arguing that they compete. This project focuses on various facets in the relationship between shared mobility and public transit, including: (1) circumstances by which microtransit and transportation network companies complement or compete with public transit, (2) how demand-responsive shared mobility services can fill in public transit service gaps in various contexts, and (3) how – in underserved rural and suburban areas that lack high-quality transit – electric vehicle carsharing can be deployed equitably and cost-effectively.

Related Publications

policy brief | May 2023

Transportation Network Companies Might Be Pulling Riders from Public Transit, but This Could Change

Read more
policy brief | Sep 2024

Communities Are Experimenting with Microtransit to Fill Critical Gaps in Public Transit Service – What Have We Learned so Far?

Read more
published journal article | Aug 2024

Environmental Impacts of Transportation Network Company (TNC)/Ride-Hailing Services: Evaluating Net Vehicle Miles Traveled and Greenhouse Gas Emission Impacts within San Francisco, Los Angeles, and Washington, D.C. Using Survey and Activity Data
Sustainability

Read more

Risk Assessment for Security Threats and Vulnerabilities of Autonomous Vehicles

Status

Complete

Project Timeline

July 22, 2022 - October 31, 2023

Principal Investigator

Qi Alfred Chen

Project Team

Ziwen Wan

Sponsor, Program & Award Number

RIMI: RIMI-5B-03
(Also see the UC ITS page)

Areas of Expertise

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

Team Departmental Affiliation

Information and Computer Science

Project Summary

In the coming decades, advancements in connected and automated vehicles (CAVs) have the potential to transform communities and mobility. As these technologies progress, policymakers and practitioners will need tools and information to proactively design policies, actions, and practices that will avoid potential negative impacts and unintended consequences and facilitate sustainable and equitable outcomes. This white paper project will summarize and classify realistic CAV-related security threats and vulnerabilities with the goal of helping stakeholders identify research needs, barriers to implementation, and strategies to address such issues. This will be accomplished by first conducting an extensive review of CAV system security vulnerabilities (e.g., sensing, control, artificial intelligence, networking, and computing). Second, the researchers will classify these threats based on common characteristics from a policymaker perspective and identify strategies to mitigate threats.

Related Publications

research report | Apr 2024

Risk Assessment for Security Threats and Vulnerabilities of Autonomous Vehicles

Read more
policy brief | Apr 2024

How Risky Are Cyber Security Threats Against Autonomous Vehicles?

Read more

Rail Transit Ridership in California: Lessons Learned from Station Area Assessments

Status

Complete

Project Timeline

February 22, 2022 - December 31, 2023

Principal Investigator

Michael McNally

Sponsor, Program & Award Number

RIMI: RIMI-4D

Areas of Expertise

Public Transit, Shared Mobility, & Active Transportation Travel Behavior, Land Use, & the Built Environment

Team Departmental Affiliation

Civil and Environmental Engineering

Project Summary

Emerging evidence shows that rail transit ridership has recuperated unevenly—at different rates in different places—as California has emerged from the COVID-19 pandemic. Stations that serve central business districts, for example, show slower gains in rail transit passengers compared to stations with mixed income residents and mixed uses in suburban locations. It is not yet clear what is causing this difference, but this disparity signals that post-COVID ridership will be different from what was observed in the past, and some station areas will likely need to develop strategies that account for this new reality. This study examines how various characteristics (e.g., land use, development density, the pedestrian environment) affect transit ridership pre- and post-COVID and how they differ across station types based on longitudinal data for 242 rail stations belonging to Bay Area Rapid Transit, San Diego Metropolitan Transit System, Sacramento Regional Transit, and LA Metro between 2019 and 2021. Key findings include an overall 72% decrease in station-level ridership, but changes were not uniform. Station areas with a higher number of low-income workers and more retail or entertainment jobs tend to have lower ridership declines, while areas with a large number of high-income workers, high-wage jobs, and higher job accessibility by transit had more ridership losses.

Related Publications

published journal article | Dec 2025

Rail transit ridership changes in COVID-19: Lessons for station area planning in California
Journal of Urban Mobility

Read more
research report | Sep 2024

Rail Transit Ridership Changes in COVID-19: Lessons from Station Area Characteristics

Read more
policy brief | Sep 2024

Decline of Rail Transit Requires New Strategies

Read more

Benefits, Challenges, and Opportunities of Different Last-Mile Delivery Strategies

Status

Complete

Project Timeline

June 1, 2022 - March 1, 2024

Principal Investigator

Michael HylandMichael Hyland

Project Team

Jean-Daniel Saphores, Younghun Bahk

Sponsor, Program & Award Number

RIMI: RIMI-3H

Areas of Expertise

Freight, Logistics, & Supply Chain

Team Departmental Affiliation

Civil and Environmental Engineering

Project Summary

The rapid growth of e‐commerce and has had significant impacts on the way consumers shop and on the logistics behind delivering the products they order. This shift has resulted in significant changes for retail as well as for business-to-business, business-to-consumer, and consumer-to-consumer distribution. Overall, supply chain structures have been modified to allow for the efficient flow of goods to satisfy the needs of today’s rapid delivery services. This project focuses on the end of the distribution process–the last mile–where changes in consumer shopping behaviors have resulted in changes in related travel behaviors. When California developed its Sustainable Freight Action Plan, it missed an opportunity to consider the relevance of the last mile distribution and e‐commerce segment. The last two years have demonstrated how important this segment is, not only for the economy, but also for delivering much‐needed goods to the people. This growing segment is stressing local infrastructure and generating congestion, pollution, and other negative effects. At the same time, it is the segment that could help the state’s decarbonization efforts because its characteristics may offer opportunities for the introduction and use of cleaner technologies. This project will evaluate the success of innovative and emerging last mile technologies and services in responding to changes in demand. It will also quantify the role of these services in reducing the environmental footprint of last mile logistics. This study leverages the extensive work conducted by the research teams at the Universities of California, Davis and Irvine on freight modeling in general, and on e‐commerce and consumer behavior in particular. Building on this past work, this research will explore the benefits and drawbacks of new technologies and innovations in last mile distribution operations and investigate what innovations, regulations, and infrastructure changes are needed to contend with changes in shopping and travel behavior. The team will synthesize the findings of the previous research and integrate the results into new rounds of simulation and optimization modeling while paying particular attention to key inputs. Researchers will also identify gaps in the modeling efforts and establish the unanswered questions, e-commerce- and travel-related issues, and policies that existing methodologies cannot address. Finally, the team will evaluate the system and regulatory requirements conducive to the best performance and compare them to existing conditions.

Related Publications

policy brief | Sep 2025

New Innovative Last-Mile Delivery Strategies Have Environmental and Equity Benefits, But There Can be Trade-Offs

Read more
published journal article | Apr 2024

Electric vehicles in urban delivery fleets: How far can they go?
Transportation Research Part D: Transport and Environment

Read more
research report | Jan 2025

Benefits, Challenges, and Opportunities of Different Last-Mile Delivery Strategies

Read more
published journal article | Sep 2025

Assessing the sustainability of last-mile distribution strategies to manage expedited shipping with dynamic and stochastic demand
Transportation Research Part E: Logistics and Transportation Review

Read more

Examining the Statewide Impact of Vehicle Grid-Integration Strategies on California’s Future Electricity Grid

Status

Complete

Project Timeline

March 1, 2022 - February 29, 2024

Principal Investigator

Stephen Ritchie

Project Team

Behdad Kiani

Sponsor, Program & Award Number

RIMI: RIMI-3K

Areas of Expertise

Zero-Emission Vehicles & Low-Carbon Fuels

Team Departmental Affiliation

Civil and Environmental Engineering

Project Summary

As California nears 1 million electric vehicles (EVs) on the road with a goal of 5 million by 2030, the ability of the state electricity grid to support charging these vehicles must be carefully studied and any grid upgrades must be meticulously planned. In addition to representing a significant new energy load for California utilities, these millions of EVs have the potential to provide a tremendous resource through vehicle-to-grid (V2G) power. EVs can store energy, provide flexible load and demand response, provide emergency backup power, and offer ancillary services that stabilize distribution grid operations. How do these benefits at the utility grid level translate to statewide electricity grid benefits? And how can flexible loads from EVs and V2G power help the California Independent System Operator (CAISO) manage the future California grid? This project will examine future scenarios of EV market penetration in California utility territories and address questions related to regional and statewide grid impacts and opportunities. The project will assess current policy and make recommendations for future development of EV-grid market rules, regulations, and rate structures. It will examine questions about the equity and fairness of proposed “dynamic” utility rate structures for residents of single-family homes and multi-unit dwellings, and will examine geographic differentiation of more elaborate future utility rate and CAISO market structures.

Related Publications

op-ed | Sep 2023

How California can use electric vehicles to solve its blackouts

Read more
white paper | Feb 2025

Electric Vehicle Charge Management Strategies to Benefit the California Electricity Grid

Read more
policy brief | Oct 2024

Policy Considerations for Advancing Bidirectional Electric Vehicle Charging in California

Read more
presentation | Apr 2024

Electric Vehicle-Grid Integration Concepts and Recent Studies

Read more

Posts navigation

Older posts
When autocomplete results are available use up and down arrows to review and enter to go to the desired page. Touch device users, explore by touch or with swipe gestures.

Recent Posts

  • Research in Motion: Evaluating Equity in Transportation and Hazard Preparedness Plans: A Multi-Level Governance Approach
  • Research in Motion: Using a “Bathtub Model” to Analyze Travel Can Protect Privacy While Providing Valuable Insights
  • Research in Motion: The Missing Link in Automated Vehicle Safety: Projected Braking and Realistic Driving Behavior
  • PRIME Alumni Spotlight: Miles Shaffie
  • TRIP Alumni Spotlight: Sara-Grace Lien

Recent Comments

No comments to show.

Archives

  • November 2025
  • October 2025
  • September 2025
  • August 2025
  • July 2025
  • June 2025
  • May 2025
  • February 2025
  • January 2025
  • October 2024
  • September 2024
  • August 2024
  • July 2024
  • June 2024
  • May 2024
  • April 2024
  • February 2024
  • December 2023
  • November 2023
  • September 2023
  • April 2023
  • November 2022
  • October 2022
  • September 2022
  • May 2022
  • April 2022
  • March 2022
  • February 2022
  • January 2022
  • November 2021
  • October 2021
  • August 2021
  • April 2021
  • January 2021
  • December 2020
  • November 2020
  • August 2020
  • July 2020
  • June 2020
  • May 2020
  • April 2020
  • March 2020
  • February 2020
  • January 2020
  • December 2019
  • November 2019
  • May 2019
  • April 2019
  • February 2019
  • January 2019
  • December 2018
  • November 2018
  • October 2018
  • September 2018
  • May 2018
  • April 2018
  • March 2018
  • February 2018
  • January 2018

Categories

  • Award
  • News
  • Research in Motion
  • Spotlight

Anteater Instruction and Research Bldg (AIRB)
Irvine, CA 92697
Phone: 949-824-5989 | Fax: 949-824-8385

  • linkedin
Subscribe to the ITS- Irvine mailing list Subscribe to Events Calendar

About

  • Leadership
  • Affiliated Centers
  • ITS-Irvine Policies
  • Contact Us

Research

  • Areas of Expertise
  • Publications
  • Projects
  • Requests for Proposals

People

  • Researchers
  • Administrative Staff
  • Current Students
  • PhD Graduates
  • Past Faculty Associates

Press

  • News
  • Events

©2025 ITS-Irvine