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published journal article

Electric Vehicle Charging as a Monthly Budget: Portfolio Preferences Across Working Americans

Abstract

The researchers examined electric vehicle (EV) charging location preferences by investigating how drivers allocate monthly charging sessions across home, workplace, and public locations. In contrast to earlier studies that treat charging location as a one-time, discrete choice, they examined preferences for combinations of all three locations over a monthly period. They employed a multiple discrete–continuous extreme value (MDCEV) model using stated preference data from 881 employed EV drivers across the United States. Results show that 88.9% of charging decisions involve multiple locations. Home charging is preferred overall, followed by workplace and public. Drivers with private driveways, single-family homes, or solar panels, as well as older adults have higher home charging preferences, though battery storage moderates the pull of solar toward home. Urban residents rely more on public charging, while workplace charging is highly price-elastic, offering employers a demand management lever. The study underscores the importance of examining charging behavior as a portfolio allocation decision.

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published journal article

Zero-Emission Vehicle Transition in California’s Construction Industry

Publication Date

June 21, 2026

Author(s)

Shakib Kafashan, Jean-Daniel Saphores

Abstract

As climate change intensifies, transitioning the construction sector away from fossil fuels is vital to reducing global greenhouse gas emissions and localized urban pollution. This paper assesses the economic feasibility of electrifying construction machinery by developing an Annualized Cost of Ownership framework that incorporates mobile charging solutions, internalizes environmental and public health operational externalities (CO2, PM2.5, NOx, and SO2), and relies on Monte Carlo simulation with Cholesky decomposition to capture the interdependencies among cost drivers. They analyze twenty distinct models of excavators and wheel loaders—the two largest contributors to construction-machinery emissions—comprising functionally equivalent diesel and battery-electric variants. Their results show that several compact electric models are already cost-competitive even without internalizing environmental and public health operational externalities. When these are accounted for, the economic advantage of electric machinery increases, particularly in denser urban areas where local air pollution damages are severe. While projected battery cost reductions further lower electric ownership costs, the magnitude of this effect is modest. However, the weak penetration of electric construction equipment in the US underscores that targeted policy interventions—such as point-of-sale rebates, green procurement mandates, tax credits, charging infrastructure subsidies, or the creation of low-emission zones and noise ordinances that advantage electric construction machinery—are needed to accelerate market adoption. These measures are particularly critical in densely populated urban areas, where internalizing local air pollution and public health externalities significantly amplifies the economic value of zero-emission machinery.

research report

Autonomous Vehicle Safety Performance in Mixed Traffic: Insights from NHTSA Crash Data

Abstract

The safe deployment of autonomous vehicles (AVs) depends on the ability of automated driving systems (ADS) to handle rare, complex, and safety-critical “edge cases.” This study develops a novel framework for identifying and analyzing such scenarios using the National Highway Traffic Safety Administration (NHTSA) ADS crash dataset. Two complementary approaches are applied. First, large language models (LLMs) are used to directly analyze crash narratives, identifying edge cases through high-risk keyword and phrase detection and anomaly-based rarity analysis. Second, LLMs are employed to extract structured variables from narrative fields, which are then analyzed using hierarchical clustering to systematically isolate unusual crash groups. Edge cases are characterized by a higher prevalence of unusual crash partner behaviors, non-motorist involvement, roadway anomalies, and disengagement of AV systems, highlighting their distinct and atypical nature. The findings underscore the importance of focusing AV evaluation on rare, high-risk scenarios that challenge ADS performance. The study advances AV safety research and can provide a foundation for refining testing protocols, safety standards, and regulatory frameworks to better capture the operational limits of AVs.

policy brief

Planning for the Next Big Earthquake: A New Tool for Transportation Agencies

Publication Date

July 15, 2026

Author(s)

Tianyu Han, Bingyu Zhao, Kelly Tang, Louise Comfort, Kenichi Soga

Abstract

Earthquakes pose a persistent and significant threat to the movement of people, goods, and services. While agencies have made progress on emergency response, planning for recovery (how quickly transportation systems can be restored after a major event) remains limited. A key challenge is that earthquake modeling and transportation system modeling have remained largely separate efforts, making it difficult for agencies to anticipate disruptions, prioritize investments, and coordinate recovery across jurisdictions. To address this gap, the research team worked with agency stakeholders, such as BART and Caltrans, and the geotechnical and structural earthquake engineers at UCLA to develop an integrated modeling tool that links earthquake impacts to transportation system performance and recovery. The team applied it to the Berkeley Hills corridor, a critical connection between the inner East Bay and Contra Costa County served by the BART Berkeley Hills Tunnel and the parallel Caldecott Tunnel on State Route 24. Four scenarios of increasing severity were tested, from minor tunnel damage lasting a few weeks to full closure lasting a year or more, focusing on the busy weekday morning commute. The tool is designed to support recovery planning in other corridors as well.

research report

Pathway to a Comeback: Student Transit Passes Can Drive Ridership and Equity in Post-Pandemic California

Abstract

This study investigates free and reduced fare pass programs (FRFPs) for K-12, post-secondary, and college students across California since the COVID-19 pandemic and their role in ridership recovery. A survey of 67 transit agencies, including 34 with established FRFPs, indicates that most of them maintained their FRFPs between fiscal years 2018-2019 and 2022-2023, showcasing agencies’ resilience despite financial uncertainty. LA Metro’s GoPass enrolled over 241,000 students and generated 1.2 million monthly boardings, inspiring similar initiatives. Post-pandemic, K-12 FRFPs saw significant expansion, improved funding, and a surge in ridership across participating agencies. These findings underscore the positive influence of fare-based incentives on student mobility and attendance.

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published journal article

Exploring Electric Vehicle Driver Activities and Expenditure While Using DC Fast Chargers

Abstract

Public Direct Current Fast Charging (DCFC) infrastructure is in its nascency, may not be profitable, and locations may not provide the amenities that consumers want. Using survey data from California this paper explores two topics related to these issues: activities of battery electric vehicle (BEV) drivers and their expenditure while using DCFC. The results show that 44.5% of BEV drivers purchase something while charging. Expenditure in establishments around chargers is $39.82 on average, while expenditure on charging is $10.35 to $16.07 on average. Most spending occurs at cafés, restaurants, or bars; grocery or convenience stores; and department or big-box stores.

research report

Assessing the Role of Dealerships in Expanding Equitable Access to Zero-Emission Vehicles in California

Abstract

This study examines the relationship between levels of access to zero-emission vehicles (ZEVs) at car dealerships in California and rates of ZEV adoption in surrounding areas. ZEV accessibility scores for census tracts—based on available ZEV inventory and proximity to dealerships—correlated significantly with ZEV adoption rates, even after controlling for income, demographics, charging infrastructure, and consumer incentives. The study results suggest that a 1% increase in ZEV accessibility correlated with an increase in ZEV adoption by 0.73% in disadvantaged communities (DACs) versus 0.125% in non-DACs. This indicates a latent demand in DACs constrained by supply-side barriers. Dealership-based incentives positively correlated with local ZEV adoption. Policies that support equitable inventory distribution among dealerships, expanded dealership-based incentive programs, and coordination with charging infrastructure planning may increase ZEV adoption in DACs.

policy brief

Increasing Access to Zero-Emissions Vehicles at Dealerships Could Increase Adoption and Improve Equity Outcomes

Abstract

California has set a target of achieving 100% zero-emission vehicle (ZEV) sales by 2035. While the state has made substantial progress, with ZEVs accounting for roughly 25% of new vehicle sales in 2025, adoption remains uneven across communities. Disadvantaged communities (DACs), which face disproportionate exposure to air pollution, continue to lag in ZEV uptake. Most DAC-related policy efforts to date have focused on demand-side interventions, such as consumer purchase incentives, rather than supply-side approaches that increase vehicle availability. Because more than half of ZEV sales in California occur through franchised dealerships, they are a critical gateway through which consumers access these vehicles and may represent an important leverage point for increasing adoption. To better understand the linkage between ZEV adoption and dealerships, the research team examined levels of access to ZEVs at car dealerships across California and rates of ZEV adoption in surrounding areas. Each census tract was assigned a ZEV accessibility score that combined ZEV inventory at nearby dealerships and distance to dealerships. While the study can help determine whether dealership availability is associated with higher rates of nearby ZEV adoption, the results should be interpreted as correlational rather than causational.

research report

Exploring Transportation Mode Choice and Participation in LA Metro’s “GoPass” Program Among Los Angeles Community College Students

Abstract

This research evaluates LA Metro’s GoPass program—a fare-free transit initiative for K-12 and community college students—through a survey of Los Angeles Community College District (LACCD) students. The research team investigated students’ travel preferences through a discrete choice experiment, assessed GoPass awareness and participation impacts on transit use, and analyzed spatial and seasonal ridership patterns from TAP card records. GoPass participation increased transit use by 26 percentage points for school trips and 19 percentage points for discretionary trips, with greater benefits for socioeconomically disadvantaged students. Even students aware of GoPass but not participating showed a 5.8 percentage point increase in school related transit use. However, 39% of eligible students were unaware of the program, and car access reduced transit use probability by 37 percentage points. The discrete choice experiment revealed students valued travel time savings at $27–$54 per hour and Wi-Fi availability at $6–$7 per trip. Modest travel time reductions generated larger welfare gains than free fares alone, suggesting service improvements may offer better returns than fare subsidies. Analysis of 1.1 million TAP card records showed substantial seasonal variation: summer ridership declined 37.5% for buses and 32.2% for rail. Single-vehicle households maintained more consistent usage (+11.9%), while three-vehicle households showed the largest declines (-40.9%). Areas with high transit stop density and high violent crime maintained more consistent usage, reflecting transit-dependent populations. These findings demonstrate that increasing student transit ridership requires addressing service quality, coverage, and program awareness beyond fare reductions alone.

research report

Understanding Post-Pandemic Travel Behavior Patterns and Trends in California

Abstract

The COVID-19 pandemic fundamentally reshaped global mobility, forcing a departure from previous travel norms. In California, initial declines in public transit and ride-hailing were accompanied by a surge in private vehicle interest and shifts to active travel. To assess whether spatial and temporal travel patterns shifted between 2019 and 2023, this study analyzed Performance Measurement System freeway data, regional transit boarding records, and spatial econometric modeling of Streetlight Insight data. The findings reveal a near-recovery of weekday freeway volumes and stable weekend patterns, yet an uneven transit recovery that favors buses over rail and weekends over weekdays. There was significant spatial dependence in active transportation; while the primary factors influencing walking and cycling remain consistent, their relative magnitudes have shifted. Ultimately, Californians’ choices of transportation modes are different after the pandemic than they were before it. Integrating these altered patterns into current planning frameworks is essential for developing resilient, equitable, and sustainable transportation policies.