policy brief

Shifting a Portion of Plug-In Electric Vehicle Travel Patterns Could Significantly Cut Peak Power Demand

Publication Date

August 25, 2025

Associated Project(s)

Planning the Adoption of Electric Vehicles in the Bay Area: Environmental Benefits vs. Electric Energy Costs

Author(s)

Marta Gonzalez

Areas of Expertise

Safety, Public Health, & Mobility Justice Zero-Emission Vehicles & Low-Carbon Fuels

View policy brief

Abstract

Plug-in electric vehicles (PEVs) are among the most promising strategies for reducing transportation-related emissions and mitigating their impacts on both the environment and public health. Historically, PEV adoption has been slowed by three key barriers: range anxiety, limited charger availability, and high purchase costs. Recent advances — including improvements in battery technology, tax incentives, and subsidized charging programs — have begun to ease these challenges, leading to steadily increasing adoption rates. Planning for the mobility needs of PEVs is particularly important due to the vulnerability of the power grid to outages that can cascade drastically. Yet a common limitation in current PEV analyses is their narrow focus on mobility patterns, often restricted to estimating simple variables like arrival or departure times. Few studies have incorporated individual mobility needs at a metropolitan scale into planning for electricity demand management. To address this gap, this study simulated daily travel patterns for the entire Bay Area population using TimeGeo, a mobile phone-based urban mobility model. TimeGeo identifies home, work, and other activity locations for individuals based on the timing and frequency of their phone calls. These data can be used to simulate the travel behavior of PEV owners, combined with vehicle usage rates drawn from U.S. Census data and the California Plug-in Electric Vehicle Driver Survey.

Related Publications

published journal article

Planning for Electric Vehicle Needs by Coupling Charging Profiles with Urban Mobility

policy brief

Enhancing Equity in the Plug-in Electric Vehicle Transition: Lessons from Rural California Electric Vehicle Owners

Publication Date

August 25, 2025

Associated Project(s)

Establishing Principles and Guiding Factors for Determining the Demand for Electric Vehicle Charging to Maximize Usefulness and Impact in Rural California (Phase 2)

Author(s)

Anya Robinson, Scott Hardman

Areas of Expertise

Zero-Emission Vehicles & Low-Carbon Fuels

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Abstract

In California, 38% of greenhouse gas (GHG) emissions come from the transport sector, and 27% of these transport emissions come from passenger vehicles. To reach carbon neutrality by 2045, as directed under Executive Order B 55 18, electrification of passenger vehicles is required. To facilitate an equitable transition to electric vehicle technologies, policymakers must account for the diverse needs and challenges faced by residents in rural communities. Rural areas often have greater travel distances and a reliance on passenger vehicles, due to a lack of alternative modes. While rural areas account for only 7% of the state’s population, California policy decisions can be far reaching and serve as guidance for other states with higher rural populations. To better understand the unique barriers and opportunities for rural electric vehicle adoption, the research team conducted in-depth interviews with 35 rural owners of plug-in electric vehicles (PEVs) across six counties in California. A PEV is an electric vehicle with a plug: either a battery electric vehicle (BEV) or a plug-in hybrid electric vehicle (PHEV). The study explored the owners’ travel behaviors, charging experiences, and motivations for PEV purchase. By centering on the experiences of current rural PEV users, the research offers insights into how infrastructure development, policy incentives, and outreach strategies can be better tailored to support equitable PEV adoption in rural communities

Related Publications

research report

Cars and Chargers in the Country: Rural PEV Owner Accounts of Charging and Travel in California

policy brief

Advancing Community-Identified Strategies to Transform Roadways in California’s San Joaquin Valley

Publication Date

August 19, 2025

Associated Project(s)

Between the Forest and the Trees: Community Strategies to Transform Roadways in California’s San Joaquin Valley

Author(s)

Douglas Houston

Areas of Expertise

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

View policy brief

Abstract

Disparities in exposure to roadway hazards (e.g., pollution, noise) remain stubbornly persistent due to structural inequalities embedded in the built environment. Research has consistently documented racial/ethnic and socioeconomic disparities in traffic exposures nationwide, including heightened exposure to heavy-duty truck traffic, a significant source of noise and pollution. Such disparities also exist in the provision of sidewalks, bike lanes, and street trees, which can help mitigate roadway dust, noise, and pollution and can increase pedestrian safety, encourage walking and cycling, and provide health benefits.

This publication describes how the research team evaluated opportunities and barriers to using a community steering committee process approach to advance environmental justice and transportation equity. Through interviews and case study analysis, the team examined the role community leaders played in the prioritization and implementation of three community-identified strategies that mitigate roadway hazards in three AB 617 communities in California’s San Joaquin Valley – Stockton, South Central Fresno, and Arvin/Lamont. These strategies include (1) vegetative barriers between roadways and sensitive land uses; (2) expanded sidewalk infrastructure; and (3) revised heavy duty truck route designations.

Related Publications

research report

Between the Forest and the Trees: Community Strategies to Transform Roadways in California’s San Joaquin Valley

preprint journal article

Optimal Fare Policy and Fleet Sizing for an Integrated Fixed-Route Transit and Microtransit System

Publication Date

August 1, 2025

Associated Project(s)

Balancing Fares and Demand: Exploring Pricing Strategies for Microtransit and Fixed-Route Transit

Author(s)

Ritun Saha, Siwei Hu, Michael Hyland

Areas of Expertise

Transportation Economics, Funding, & Finance

View preprint journal article

Abstract

Integrating microtransit with fixed-route transit (FRT) can improve travelers’ mobility by leveraging the benefits of microtransit’s flexibility and FRT’s high passenger capacity. However, the high operating cost of microtransit presents a challenge, which calls for a careful evaluation of the trade-offs between mobility gains and operational cost. To address this need, this paper develops a modeling approach and solution procedure to identify Pareto-optimal designs. The researchers focus on design parameters of practical interest, namely, fare policies and microtransit fleet size. To explore these trade-offs, a bi-level and bi-objective (i.e., minimize taxpayer subsidy and maximize mobility-based consumer welfare) modeling framework, with an agent-based transportation system simulation model at the lower level and a multi-objective Bayesian Optimization (BO) model at the upper level is proposed. The research team applied the modeling and solution approach to Lemon Grove, California (a suburban area in San Diego County). Results revealed a diverse set of solutions along the Pareto frontier, indicating that some naive microtransit fare strategies are suboptimal. Notably, Pareto-optimal designs feature a 50-100% discount for microtransit to FRT transfers, as well as peak-period fare multipliers between 1.8x and 3.5x to manage time-varying demand effectively.

research report

Between the Forest and the Trees: Community Strategies to Transform Roadways in California’s San Joaquin Valley

Publication Date

August 25, 2025

Associated Project(s)

Between the Forest and the Trees: Community Strategies to Transform Roadways in California’s San Joaquin Valley

Author(s)

Douglas Houston, Gregg Macey, Jeannine Pearce

Areas of Expertise

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

View research report

Abstract

Expanding participation of historically disenfranchised groups within decision-making processes is an important strategy to increase equity within transportation planning but traditional engagement practices (e.g., public meetings, focus groups) have historically done little to address the needs of disadvantaged communities. This study evaluates the opportunities and barriers to using a community steering committee participation model within transportation planning to advance equity and environmental justice. It utilizes interview and case study analysis to examine the experiences of residents and community leaders in prioritizing community-identified strategies to mitigate roadway hazards in three AB 617 communities in California’s San Joaquin Valley – Stockton, South Central Fresno, and Arvin/Lamont. It investigates the role resident and CBO members played in the prioritization, approval, and implementation of three strategies to transform roadways and mitigate air pollution, noise, dust, and safety hazards: (1) new vegetative barriers between major roadways and sensitive land uses; (2) expanded sidewalk infrastructure; and (3) revised heavy-duty truck route designations. Findings demonstrate that “meaningful involvement” for impacted communities within transportation planning will require officials, residents, and organizations to commit to an ongoing process of experimentation and learning about the most effective approaches for advancing transportation equity and environmental justice.

Related Publications

policy brief

Advancing Community-Identified Strategies to Transform Roadways in California’s San Joaquin Valley

preprint journal article

Flexible Agent-based Modeling Framework to Evaluate Integrated Microtransit and Fixed-route Transit Designs: Mode Choice, Supernetworks, and Fleet Simulation

Publication Date

May 29, 2024

Associated Project(s)

Job Access, Agency Cost, and VMT Impacts of Offering Microtransit alongside Fixed-route Transit

Author(s)

Siwei Hu, Michael Hyland, Ritun Saha, Jacob Berkel, Geoffrey Vander Veen

Areas of Expertise

Public Transit, Shared Mobility, & Active Transportation

View preprint journal article

Abstract

The integration of traditional fixed-route transit (FRT) and more flexible microtransit has been touted as a means of improving mobility and access to opportunity, increasing transit ridership, and promoting environmental sustainability. To help evaluate integrated FRT and microtransit public transit (PT) system (henceforth “integrated fixed-flex PT system”) designs, the research team proposes a high-fidelity modeling framework that provides reliable estimates for a wide range of (i) performance metrics and (ii) integrated fixed-flex PT system designs. The researchers formulate the mode choice equilibrium problem as a fixed-point problem wherein microtransit demand is a function of microtransit performance, and microtransit performance depends on microtransit demand. The team proposes a detailed agent-based simulation modeling framework that includes (i) a binary logit mode choice model (private auto vs. transit), (ii) a supernetwork-based model and pathfinding algorithm for multi-modal transit path choice where the supernetwork includes pedestrian, FRT, and microtransit layers, (iii) a detailed mobility-on-demand fleet simulator called FleetPy to model the supply-demand dynamics of the microtransit service. This paper illustrates the capabilities of the modeling framework by analyzing integrated fixed-flex PT system designs that vary the following design parameters: FRT frequencies and microtransit fleet size, service region structure, virtual stop coverage, and operating hours. The research includes case studies in downtown San Diego and Lemon Grove, California. The computational results show that the proposed modeling framework converges to a mode choice equilibrium. Moreover, the scenario results imply that introducing a new microtransit service decreases FRT ridership and requires additional subsidies, but it significantly increases job accessibility and slightly reduces total VMT.

Related Publications

research report

Job Access, Agency Cost, and VMT Impacts of Offering Microtransit alongside Fixed-route Transit

policy brief

Integrating Microtransit Service with Traditional Fixed-Route Transit Costs More but Greatly Improves Access to Jobs

conference paper

Accessibility of Shared Automated Vehicles for the Visually Impaired Travelers

Publication Date

July 29, 2025

Associated Project(s)

Accessibility of Shared Automated Vehicles for Visually Impaired Travelers

Author(s)

Pei (Peggy) Wang, Benjamin Yi

Areas of Expertise

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

View conference paper

Abstract

In this study, the researchers conducted semi-structured interviews with 15 visually impaired individuals. The research team first explored their perspectives regarding their current travel behaviors and transportation experience. The research team then explored the potential of using Shared Automated Vehicles (SAVs) to enhance their travel experiences and address their existing transportation challenges. Results of the first part of the study revealed that most participants primarily worked from home, while those who commute largely relied on public transit. For doctor’s appointments, rideshare was the most common method of transportation followed by public transit and riding with family. Ridesharing also emerged as the dominant mode of transportation for other essential activities such as visiting family, socializing, attending events, or work-related travel. Results of the second part of the study revealed a range of expectations and concerns related to SAVs, particularly in the areas of accessibility, safety, communication, and affordability. Most participants expressed enthusiasm for the potential benefits of SAVs to increase independence and access to underserved areas. They also highlighted critical accessibility needs, such as reliable means to identify assigned vehicles, accurate drop-off locations, and accessible interfaces. Affordability emerged as the key factor influencing potential adoption, with many participants indicating a preference for SAVs if they were priced competitively with existing transportation options, especially in comparison with traditional rideshare services. Findings of this study provide valuable insights for policymakers, transportation planners, and SAV developers to ensure that future automated transportation solutions are fully inclusive and meet the diverse needs of all visually impaired travelers.

Related Publications

policy brief

Shared Automated Vehicles Could Greatly Benefit Visually Impaired Travelers if Designed and Operated with Their Needs in Mind

research report

Accessibility of Shared Automated Vehicles for Visually Impaired Travelers

policy brief

How is Climate Change Affecting Landslide Susceptibility in California?

Publication Date

July 1, 2025

Associated Project(s)

Exploring the Use of Machine Learning-Based Landslide Susceptibility Assessments to Protect California’s Transportation Infrastructure

Author(s)

Shabnam Semnani

Areas of Expertise

Infrastructure Delivery, Operations, & Resilience

View policy brief

Abstract

Environmental shifts resulting from climate change have led to increased risk of natural hazards such as drought, wildfires, floods, and landslides, which all represent major threats to the state’s infrastructure. One particular risk that is posed by greater precipitation in areas affected by wildfires, which can lead to an increase in landslide hazard. There is little research available for predicting future landslide susceptibility. To address this gap, the research team developed a landslide susceptibility assessment framework which reflects changing climate conditions under different levels of projected greenhouse gas emissions and applied it to assess the vulnerability of California’s transportation infrastructure.

Related Publications

published journal article

Important Considerations in Machine Learning-based Landslide Susceptibility Assessment Under Future Climate Conditions

policy brief

Shared Automated Vehicles Could Greatly Benefit Visually Impaired Travelers if Designed and Operated with Their Needs in Mind

Publication Date

August 1, 2025

Associated Project(s)

Accessibility of Shared Automated Vehicles for Visually Impaired Travelers

Author(s)

Pei (Peggy) Wang

Areas of Expertise

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

View policy brief

Abstract

Automated vehicles (AVs) are one of the most significant technological advances in transportation. The benefits of AV technologies could be maximized by increasing vehicle occupancy through pooling and ridesharing, integrating AV use with high-capacity transit systems (e.g., using AVs to complement existing transit), and promoting multimodality (e.g., connecting travelers to public transit). Additionally, shared automated vehicles (SAVs), in which ridesharing companies (similar as today’s Uber or Lyft) offer driverless on-demand mobility services to customers, could enhance transportation access for visually impaired travelers who face unique challenges navigating current transportation systems including public transit and rideshare services. To this point, the research team interviewed 15 visually impaired individuals to understand their current transportation experience (e.g., what challenges they face and how they cope with these challenges); how SAVs might address their transportation needs and challenges; potential issues and solutions for using SAVs; how their travel behavior may change due to SAVs; and how much they would pay for SAV rides.