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
  • Support Us
  • 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
  • Support Us
  • News & Events
    • News
    • Events

Sponsor: SB1

The Influence of Housing Characteristics on Complex Travel Behavior

Status

Complete

Project Timeline

January 1, 2020 - December 31, 2020

Principal Investigator

Michael McNally

Project Team

Rezwana Rafiq

Sponsor, Program & Award Number

SB1 // STRP Faculty Research: 2020-57
(Also see the UC ITS page)

Areas of Expertise

Travel Behavior, Land Use, & the Built Environment

Team Departmental Affiliation

Civil and Environmental Engineering

Project Summary

UPDATED ABSTRACT: Recent California policy discussions suggest that the travel impacts resulting from strategies for housing growth are not well understood, in part because metropolitan growth has always occurred according to local zoning and land use plans. Fundamental alterations of local planning guidelines, in turn, have unknown transportation impacts. This project reviewed and synthesized policy and academic literature on housing-and-transportation linkages. The project team then applied a process developed in related research to categorize tour-based travel patterns and related these to household characteristics. The project team established connections between household tour behavior and residential variables, which were used to classify types of travelers. The focus of this research was on users of public transit and ride hailing services.

Related Publications

policy brief | Jun 2026

The Influence of Housing Characteristics on Complex Travel Behavior

Read more
published journal article | Oct 2021

Heterogeneity in Activity-travel Patterns of Public Transit Users: An Application of Latent Class Analysis
Transportation Research Part A: Policy and Practice

Read more
published journal article | Apr 2023

An exploratory analysis of alternative travel behaviors of ride-hailing users
Transportation

Read more

Resiliency Impacts of Plug-in Electric Vehicles in a Smart Grid

Status

Complete

Project Timeline

January 1, 2020 - December 31, 2020

Principal Investigator

Scott Samuelsen

Project Team

Ghazal Razeghi

Sponsor, Program & Award Number

SB1 // STRP Faculty Research: 2020-64
(Also see the UC ITS page)

Areas of Expertise

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

Team Departmental Affiliation

Mechanical and Aerospace Engineering

Project Summary

While plug-in electric vehicles (PEVs)may tax the electrical grid under normal operations, PEVs can provide benefits during grid outages since they are essentially mobile energy storage resources. This concept. referred to as Mobility Services+, uses PEVs as a resiliency resource during grid outages to increase the reliability and resiliency of the grid by (1) serving critical loads through vehicle-to-home (V2H) or vehicle-to-grid (V2G) electricity transmission by discharging the batteries on the PEVs, and (2) assisting in restoring the grid after an outage by providing the necessary power and energy to restart a utility asset such as a transformer. During normal operations, however, the high electricity demand of PEVs can negatively impact the distribution network by stressing system components such as transformers. This can result in accelerated aging, increased chance of failure, and ultimately reduced reliability and resiliency of the electric grid.This project assesses the impact of PEVs on the resiliency of the electricity distribution system by: (1) assessing the use of PEVs as a resiliency resource during grid outages (Mobility Services+), (2) assessing and simulating the impact of PEVs on the distribution infrastructure during normal operations, and (3) determining the local environmental impact of clustering PEVs. A previously developed model of a smart grid consisting of two distribution circuits and a distribution substation was modified to enable the use of PEVs in vehicle-to-home (V2H) and vehicle-to-grid (V2G) configurations. Scenarios were simulated in which PEVs were used to serve critical loads in a home or community shelters, and a model was developed to assess the feasibility of using PEVs in grid restoration, which determined the inrush current of the substation transformer to determine the required power and energy for startup. The use of clustered PEVs and scattered PEVs in grid restoration was also considered. During normal operations, the stress on system components from high PEV demand resulted in accelerated aging and possible failure, thereby negatively impacting distribution infrastructure during normal grid operations. Smart charging is required to retain an acceptable level of resiliency. In contrast, during grid outages, this study demonstrated that PEVs can be used as an environmentally friendly resiliency resource to both serve critical loads and facilitate grid restoration with the qualification that implementation requires system upgrades including smart switches, upgraded inverters, energy management systems, and communication links.

Related Publications

published journal article | Feb 2024

Mitigating impacts associated with a high-penetration of plug-in electric vehicles on local residential smart grid infrastructure
Journal of Power Sources

Read more
research report | Feb 2021

Resiliency Impacts of Plug-in Electric Vehicles in a Smart Grid

Read more

Transportation System Performance: Congestion Pricing, Induced Demand, and Equity

Status

Complete

Project Timeline

July 1, 2018 - June 30, 2019

Principal Investigator

Michael McNally

Project Team

Rezwana Rafiq, Chenying Qin

Sponsor, Program & Award Number

SB1 // STRP Faculty Research: 2019-31
(Also see the UC ITS page)

Areas of Expertise

Infrastructure Delivery, Operations, & Resilience Safety, Public Health, & Mobility Justice Transportation Economics, Funding, & Finance

Team Departmental Affiliation

Civil and Environmental Engineering

Project Summary

When a section of a transportation network is changed, typically in response to either current and/or forecast traffic congestion, it is relatively easy to estimate and (after project completion) to empirically measure the volume of traffic on all the sections of the network. A body of empirical evidence suggests that the majority of new capacity is in short time consumed. This leads to the common expression that states “you can’t build your way out of congestion” but such a quick conclusion belies the fact that more travel is being accommodated after capacity expansion, regardless of the resulting level of congestion. So what is this seemingly generated traffic and from where did it come? Many claim the generated traffic is induced demand, but a more nuanced characterization of the relationship between travel demand and transportation capacity is necessary to fully understand the dynamics of transportation system performance. This study will examine the objectives, assumptions, and system-wide impacts of congestion management strategies that reflect induced demand and pricing, as well as the underlying issues of social equity. Identified themes associated with the research include the measurement of economic, social, and environmental impacts of traffic congestion; the evaluation of potential strategies for improving congestion management; and the evaluation of the effects of congestion pricing on transportation and social equity. An exploratory approach will be taken and case studies will be identified in California where capacity enhancement has been completed and before/after data exists for corridor and regional performance and demographics. In addition to traffic performance, an assessment of travel behavior will utilize statewide travel surveys to identify the degree of stability in trip rates and travel time budgets as constraints on induced demand.

A New Approach to Calculating Dynamic Pricing of High-Occupancy-Toll (HOT) Lanes

Status

Complete

Project Timeline

July 1, 2018 - June 30, 2019

Principal Investigator

Wenlong Jin

Project Team

Xuting Wang, Ximeng Fan, Irene Martinez

Sponsor, Program & Award Number

SB1 // STRP Faculty Research: 2019-29
(Also see the UC ITS page)

Areas of Expertise

Transportation Economics, Funding, & Finance

Team Departmental Affiliation

Civil and Environmental Engineering

Project Summary

In the U.S., high-occupancy-vehicle (HOV) lanes are widely used on freeways to reduce congestion since the 1970s. Such lanes are reserved for cars with a minimum of two or three occupants and other qualified vehicles. Under some conditions, however, the HOV lanes are underutilized when the whole freeway system is congested. High-occupancy-toll (HOT) lanes have been one of the most successful lane management methods, which combine HOV lanes and congestion pricing strategies by charging single occupancy vehicles (SOVs) to use HOV lanes during peak periods. HOT lanes offer numerous benefits to both the operators and users by making use of the excess capacity on HOV lanes and have been implemented on State Route 91, US Route 101, and I-15 in California and other places. Generally, the operational goals for the HOT lanes are two-fold: (i) maintaining the freeflow condition; and (ii) maximizing the usage of the HOV lanes. This will help to guarantee the trip time reliability of both HOVs and paid SOVs as well as to minimize the congestion level on the general purpose (GP) lanes. The success of achieving these goals is predicated on the determination of prices dynamically, which in turn depends on an understanding of the values of time (VOTs) of SOVs. Thus, two outstanding problems are to determine a dynamic price for time-dependent demands of both HOVs and SOVs and to estimate SOVs’ VOT. This project aims to develop more effective ways to set HOT lane prices in real-time, ensuring they are used efficiently and provide reliable travel times for all drivers. The research makes three fundamental contributions: (i) presents a simpler formulation of the point queue model based on the new concept of residual capacity, (ii) proposes a simple feedback control theoretic approach to estimate the average value of time and calculate the dynamic price, and (iii) analytically and numerically proves that the closed-loop system is stable and guaranteed to converge to the optimal state, in either Gaussian or exponential manners.

Related Publications

policy brief | Aug 2024

A New Approach to Calculating Dynamic Pricing of High-Occupancy-Toll (HOT) Lanes Can Improve the Performance of Travel Corridors

Read more
published journal article | Nov 2021

A Control Theoretic Approach to Simultaneously Estimate Average Value of Time and Determine Dynamic Price for High-Occupancy Toll Lanes
IEEE Transactions on Intelligent Transportation Systems

Read more
published journal article | Oct 2020

Stable dynamic pricing scheme independent of lane-choice models for high-occupancy-toll lanes
Transportation Research Part B: Methodological

Read more

Assessment of the Employment Accessibility Benefits of Shared Autonomous Mobility Services

Status

Complete

Project Timeline

July 1, 2018 - June 30, 2019

Principal Investigator

Michael HylandMichael Hyland

Project Team

Tanjeeb Ahmed, Navjyoth Sarma, Suman Mitra

Sponsor, Program & Award Number

SB1 // STRP Faculty Research: 2019-32
(Also see the UC ITS page)

Areas of Expertise

Public Transit, Shared Mobility, & Active Transportation

Team Departmental Affiliation

Civil and Environmental Engineering

Project Summary

Connecting people to employment opportunities is one of the most important goals of a regional transportation system. However, many people, particularly low-income families, struggle to access their current jobs and other potential employment opportunities. Shared autonomous mobility services (SAMSs), which are similar to taxi and ridesourcing services except the vehicles are driverless and centrally-operated, have the potential to overcome many of the employment accessibility challenges facing commuters. This study quantifies the potential impact of SAMS modes on access to employment opportunities in the Southern California region. The results indicate: (i) the accessibility benefit differences across latent classes are modest but young workers and low-income workers do see higher benefits than high- and middle-income workers; (ii) there are substantial spatial differences in accessibility benefits with workers living in lower density areas benefiting more than workers living in high-density areas; (iii) nearly all the accessibility benefits come from the SAMS-only mode as opposed to the SAMS+Transit mode (i.e., SAMS used in coordination with transit to complete a trip); and (iv) the SAMS cost per mile assumption significantly impacts the magnitude of the overall employment accessibility benefits.

Related Publications

policy brief | May 2020

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

Read more
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

Read more
research report | Feb 2020

Assessment of the Employment Accessibility Benefits of Shared Autonomous Mobility Services

Read more

Evaluating Use of New Technologies and Services to Improve Transit and Paratransit Operations

Status

Complete

Project Timeline

January 1, 2019 - December 31, 2019

Principal Investigator

Amelia Regan

Project Team

Julius Aguma, Reza Asadi, Amari Lewis, Mandal Udayan

Sponsor, Program & Award Number

SB1 // STRP Faculty Research: 2019-39
(Also see the UC ITS page)

Areas of Expertise

Intelligent Transportation Systems, Emerging Technologies, & Big Data Public Transit, Shared Mobility, & Active Transportation

Team Departmental Affiliation

Computer Science

Project Summary

Transit operations for disabled users are notoriously expensive to provide. An interdisciplinary research team from transportation researchers in computer science, urban planning and engineering will examine two connected yet somewhat separate issues: 1) paratransit operations which serve disabled users, and 2) transit operations which among their many patrons, serve some mildly disabled users. The project team will examine the use of technologies – especially phone app based information systems and cyber-physical systems (CPS) technologies – to improve paratransit specifically and transit more generally in California communities. The use of Transportation Network Companies services to complement transit operations for disabled users will also be explored.

Methods for Analyzing Managed Lane Performance Accounting for HOV Degradation

Status

In Progress

Project Timeline

January 1, 2019 - December 31, 2019

Principal Investigator

r-jayakrishnanR. (Jay) Jayakrishnan

Project Team

Riju Lavanya, Marjan Mosslemi, Navjyoth Sarma

Sponsor, Program & Award Number

SB1 // STRP Faculty Research: 2019-30
(Also see the UC ITS page)

Areas of Expertise

Infrastructure Delivery, Operations, & Resilience

Team Departmental Affiliation

Civil and Environmental Engineering

Project Summary

The state of California has a vast network of close to 1,750 lane miles of managed lanes. This accounts for nearly 40% of the total managed lane network in the US. A managed lane facility includes High Occupancy Vehicle lanes (HOV), High Occupancy Toll lane (HOT) and Express lanes. Congestion on HOV lanes in California has been increasing over the years, with as much as 68% of total lane miles found to meet Federal standards for HOV lane degradation. As per Federal definition, an HOV facility is degraded if vehicles operating on the facility fail to maintain a minimum average operating speed (45 mph) 90% of the time over a consecutive 180-day period during morning or evening weekday peak hour periods. Caltrans have been preparing annual degradation action plans to outline measures to mitigate degradation. Despite improvements in certain corridors, the number of degraded lane miles continue to increase. Prior research has shown limitations of ‘one-dimensional’ definition for HOV lane degradation, which as an aggregate measure provides very little information to practitioners. A more nuanced approach is helpful; one that considers a variety of factors such as comparative advantage over adjacent general purpose lanes, travel time reliability, HOV access type, geometry, incidents, and demand patterns. The main objective of this project is to develop analysis and modeling methods to help in policy decisions on managed lanes, with specific focus on HOV lanes, including the performance and degradation these lanes as well as the enforcement of lane utilization rules and their violation. The second objective is to apply these methods to evaluate the effectiveness of incentive policies allowing clean air vehicles to travel in HOV lanes. The third objective is to provide new tools, including simulation techniques, for decision-making with regard to conversion of HOV lanes to HOT lanes.

Mobility of Older Adults in California: In the Era of Shared Mobility

Status

Complete

Project Timeline

January 1, 2019 - December 31, 2019

Principal Investigator

Stephen Ritchie

Project Team

Suman Mitra, Mingqi Yao, Esmaeil (Sina) Dabbagh

Sponsor, Program & Award Number

SB1 // STRP Faculty Research: 2019-33
(Also see the UC ITS page)

Areas of Expertise

Safety, Public Health, & Mobility Justice Travel Behavior, Land Use, & the Built Environment

Team Departmental Affiliation

Civil and Environmental Engineering

Project Summary

The older adult (65 and over) population in the United States is quickly growing in proportion, and it is expected to reach its highest point by 2030 when the baby boomers will have all passed age 65. In California, the elderly population is expected to grow more than twice as fast as the total population, and this growth will vary by region. Mobility is a critical element of one’s quality of life regardless of one’s age. Good mobility and decent transportation alternatives are important in enabling the older population to participate in daily activities and remain socially active. This study will examine the transportation mobility of older adults in California by analyzing data from the 2017 National Household Travel Survey, with an emphasis on those living in rural and disadvantaged areas. Individuals aging in rural and disadvantaged communities are disproportionately affected by poverty and other challenges that accompany poor economic circumstances, and in turn, may face greater challenges than their peers aging in large urban locations. Specific objectives of this research are to estimate the impact of age, and other demographic and geographic characteristics on various measures of mobility, including ability to drive, use of shared mobility services, use of public transportation, trip frequency for both discretionary and nondiscretionary travel, unmet travel demand, barriers to using public transportation, and satisfaction with available transportation options.

Related Publications

published journal article | Dec 2021

Gender differences in elderly mobility in the United States
Transportation Research Part A: Policy and Practice

Read more
published journal article | Mar 2019

Use of Ride-Hailing Services among Older Adults in the United States
Transportation Research Record

Read more

Simulation of Zero-Emissions Self-Driving Drayage Trucks in a Busy Freight Corridor

Status

Complete

Project Timeline

January 1, 2019 - December 31, 2019

Principal Investigator

Jean-Daniel Saphores

Project Team

Bumsub Park, Monica Ramirez-Ibarra, Lu Xu

Sponsor, Program & Award Number

SB1 // STRP Faculty Research: 2019-28
(Also see the UC ITS page)

Areas of Expertise

Freight, Logistics, & Supply Chain Zero-Emission Vehicles & Low-Carbon Fuels

Team Departmental Affiliation

Civil and Environmental Engineering

Project Summary

Port operations require a large number of diesel engines to power trucks, trains, ships, and cargo-handling equipment. Diesel engines contribute to vast amounts of air pollution that impairs the health of those residing or working in proximity to ports. Further, diesel exhaust emissions contribute substantially to regional air pollution. For years, traffic operations along highways have disproportionately burdened low-income and minority communities in the form of exposure to air pollutants and their associated health impacts. To address this issue, improved traffic safety and air quality are the primary objectives of the I-710 corridor project, a freeway improvement project along the I-710 freeway in Los Angeles County between Ocean Boulevard and State Route 60 (SR-60), which covers approximately 18 miles of the I-710. This study estimates air pollution and associated health effects of the fleet replacement of diesel trucks for autonomous trucks. The primary objective is to quantify the possible benefits associated with the incorporation of autonomous vehicles within the study area in the context of environmental justice. This project incorporates a microscopic traffic simulation to study traffic improvements associated with the addition of lanes to the I-710 and the replacement of San Pedro Bay ports diesel trucks with autonomous (self-driving), zero emission, trucks. The impact on traffic of autonomous trucks was simulated using TransModeler 5.0, which allows simulating autonomous vehicles with Cooperative Adaptive Cruise Control (CACC). CACC is a subset of the broader class of automatic vehicles speed and control systems. Emission estimates of nitrogen oxides (NOx) and particulate matter (PM2.5 and PM10) were then quantified using the Operating Mode (OpMode) lookup tables based on EPA’s MOVES model. Results show that autonomous truck operations could allow a 90% increase in demand while providing a 13% improvement in the traffic performance of port-related vehicles while reducing by 70% NOx, PM2.5, and PM10 emissions within the study area.

Related Publications

published journal article | Mar 2023

Health and equity impacts from electrifying drayage trucks
Transportation Research Part D: Transport and Environment

Read more
Phd Dissertation | Sep 2022

Electrification, Connectivity, & Active Demand Management: Addressing the traffic, health, and environmental justice impacts of drayage trucks in Southern California

Read more
policy brief | Jan 2025

What are the Public Health and Environmental Implications of Drayage Truck Electrification Targets in California?

Read more

Improving the Distribution of Densities in Southern California

Status

Complete

Project Timeline

January 1, 2019 - December 31, 2019

Principal Investigator

Jae Hong Kim

Project Team

Xiangyu Li

Sponsor, Program & Award Number

SB1 // STRP Faculty Research: 2019-36
(Also see the UC ITS page)

Areas of Expertise

Travel Behavior, Land Use, & the Built Environment

Team Departmental Affiliation

Urban Planning and Public Policy

Project Summary

Many of the biggest transportation challenges in Southern California arise from the lack of concentration of densities. However, little is known about how to address this critical problem and its adverse consequences. While recent years have witnessed increasing efforts to expand public transit services and encourage compact development in transit areas, there is a dearth of research providing detailed guidance for improving the distribution of densities in the region. Furthermore, existing studies have tended to focus on the City of Los Angeles, resulting in lost opportunities for understanding what challenges exist in the rest of the region, particularly in (suburban) places with great potential for density concentrations. This project will examine the complexity of urban densification dynamics with a focus on thirty selected cities in Southern California where public transit services will be widely available and thus land use intensification will be highly desired in the future. Specifically, the project will (i) conduct an exploratory analysis to identify ways in which urban densification takes place through zoning and actual land use changes that should be jointly addressed in coordination with transportation planning; (ii) develop a model to better understand how zoning has changed (in relation to the expansion of public transit services), to what extent zoning changes have led to shifts in actual land use patterns, and how changes in land use induce further zoning modifications in nearby areas; and (iii) identify hotspots that deserve attention for more strategic densification in the region.

Related Publications

research report | Jan 2020

Improving the Distribution of Densities in Southern California

Read more
published journal article | Dec 2021

Building more housing near transit: A spatial analysis of residential densification dynamics
Transport Policy

Read more

Posts navigation

Older posts
Newer 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

  • TRIP Student Spotlight: Kai Friedrich
  • PRIME Student Spotlight: Ryan Shaffie
  • TRIP Student Spotlight: Charlotte Dunlap
  • PRIME Student Spotlight: Kingston Wu
  • Faculty Spotlight: Dr. Michael Hyland

Recent Comments

No comments to show.

Archives

  • June 2026
  • January 2026
  • 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

©2026 ITS-Irvine