policy brief

Leveraging Robotaxis to Support Transit Riders in Emergencies

Publication Date

August 1, 2025

Associated Project(s)

Improving Transportation System Resilience with Shared Automated Vehicles

Author(s)

Arash Ghaffar, Jiangbo (Gabe) Yu, Michael Hyland

Areas of Expertise

Infrastructure Delivery, Operations, & Resilience

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Abstract

Transportation systems are vulnerable to disruptive events. Rail transit systems are particularly vulnerable because their vehicles operate on fixed tracks, making it difficult for them to safely and efficiently bypass each other or disrupted sections of the rail network. To improve the resilience of transit systems in the future, we explored the use of shared automated vehicles (SAVs), also called robo-taxis, to pick up stranded passengers and deliver them to their homes or other drop-off locations, such as an unaffected transit stop. For example, transit agencies could have a contract with one or more SAV fleet operators that would allocate a certain number or percentage of their vehicles to provide transportation between stations in the transit network. The transit agency would pay a recurring fee to ensure access to SAVs during a disruption. The transit agency will agree to pay the SAV fleet provider based on either (i) the number of travelers served during a disruption, or (ii) the cumulative vehicle-hours the SAVs provide exclusive service to transit riders. To explore this concept, the research team developed a simulation model that shows how SAVs could help riders during major transit disruptions

policy brief

Beyond Transit Discounts: Comparing the L.A. Mobility Wallet and Low-Income Fare is Easy (LIFE) Programs

Publication Date

May 5, 2025

Associated Project(s)

Evaluation of a Large Scale Universal Basic Mobility Wallet in South Los Angeles – Phase I

Author(s)

Sang-O Kim, Madeline Brozen, Madeline Wander, Tamika Butler, Evelyn Blumenberg

Areas of Expertise

Safety, Public Health, & Mobility Justice

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Abstract

Transportation affordability is a major concern for low-income people and households across the United States. While car ownership rates remain relatively high, the associated costs — insurance, gas, and repairs — can place
a significant financial burden on low-income households. Even for those who own a vehicle, these costs can limit how often they use it. As a result, in Los Angeles, many low-income residents rely heavily on public transit or active transportation options. In fact, 69% of Metro bus riders report annual
household incomes below $25,000. Despite this, there is no federal mandate to financially support the mobility needs of low-income people — besides fare discounts for seniors and individuals with disabilities. In this context, Los Angeles has begun piloting a new, more ambitious mobility approach. Since 2023, the L.A. Mobility Wallet pilot — developed in partnership between Metro and the Los Angeles Department of Transportation — has sought to expand transportation access for low-income residents. Through the pilot, 1,000 participants in South Los Angeles received $150 per month for one year on a prepaid debit card to cover shared mobility services, including transit fare, bikeshare, e-scooters, ride-hail services, regional transportation (e.g., Amtrak, Greyhound), and purchases at local bike shops. The first phase of this pilot concluded in April 2024. The flexibility of a mobility wallet marks a departure from how public transit agencies traditionally assist low-income riders. This brief compares L.A.’s two primary mobility assistance programs: the Mobility Wallet pilot and Metro’s Low-Income Fare is Easy (LIFE), launched in 2019, which provides 20 free transit rides per month.

research report

Matching Technique with Authority: A Study of How Local DOTs Can Narrow the Gap between their Network Management Authority and their Analytical Capacity

Publication Date

September 8, 2025

Associated Project(s)

Matching Technique with Authority: A Study of How Local DOTs Can Narrow the Gap between their Network Management Authority and their Analytical Capacity

Author(s)

Rowland Awadagin Herbert-Faulkner, Jane Macfarlane, Karen Frick, Joan Walker

Areas of Expertise

Safety, Public Health, & Mobility Justice

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Abstract

This report explores how local DOTs can leverage advanced traffic modeling software to narrow the gap between their network management authority and their analytical capacity. Limited computational and analytical capacity among local DOTs has historically made detailed on-demand analytics inaccessible. Using the Mobiliti traffic simulation platform, we examine the City of San José’s Safer Streets program to determine the operational and social impacts of the city’s traffic management strategies. We find that imposing a 20 mph speed limit cap on residential streets in San José’s Equity Priority Communities leads to a 39% reduction in passthrough traffic on those streets, but a 76% increase in traffic on streets in the surrounding network. Using this analytical approach, instead of relying on technical assistance from MPOs network managers can more quickly gain quantified insights into the response of network dynamics to localized interventions.

Related Publications

policy brief

Mobiliti—A New Tool to Guide Safer, More Equitable Traffic Management Strategies

policy brief

Machine Learning Can Reveal Effectiveness of Traffic Safety Countermeasures

Publication Date

September 3, 2025

Associated Project(s)

Developing a Safety Effectiveness Evaluation Tool for California

Author(s)

Jia Li, Yanlin Qi, Michael Zhang

Areas of Expertise

Safety, Public Health, & Mobility Justice

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Abstract

Emerging machine learning capabilities can be leveraged to make transportation infrastructure safer and reduce fatalities by informing decisions about which countermeasures to apply at crash-prone locations. At this time, project prioritization typically involves assessing effectiveness, cost-benefit ratios, and available funding. Crash Modification Factors (CMFs) play an essential role in project assessment by predicting the effectiveness of safety countermeasures. Their applicability has limitations, however. Some of these may be overcome with innovative approaches such as knowledge-mining. The US Department of Transportation’s (DOT) CMF Clearinghouse provides practitioners with a list of reliable CMFs developed from individual studies. However, available CMFs do not cover all potential scenarios-of-interest to State DOTs because unique projects may feature novel infrastructure types or countermeasures. Experimental or observational studies are the dominant tools for estimating CMFs. However, these approaches may require years of effort to collect adequate crash data. To address these challenges, the research team developed a machine learning framework that mines CMF Clearinghouse data to uncover previously unidentified relationships. This provides a cost-effective and time-efficient solution to assessing CMFs not covered by the CMF Clearinghouse. The study proposed framework fully explores existing CMF data. The research team extensively trained and tested the proposed approach on CMF Clearinghouse data with experiments and showed that the framework can predict CMFs with reasonable accuracy. The framework flexibly incorporates heterogeneous data from the CMF Clearinghouse, captures the semantic contexts of countermeasures, and maintains data compatibility.

Related Publications

research report

Developing a Safety Effectiveness Evaluation Tool for California

research report

Drivers’ Responses to Eco-driving Applications: Effects on Fuel Consumption and Driving Safety

Publication Date

August 1, 2025

Associated Project(s)

Drivers’ Responses to Eco-driving Applications: Effects on Fuel Consumption and Driving Safety

Author(s)

Rui Lin , Pei (Peggy) Wang

Areas of Expertise

Travel Behavior, Land Use, & the Built Environment

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Abstract

Onboard eco-driving systems provide drivers with real-time information about their driving behavior and road conditions, encouraging them to optimize their driving speed and consequently reduce fuel consumption and emissions. However, there are barriers to making eco-driving a habit. To determine the elements that influence drivers’ intentions to practice eco-driving and their acceptance of eco-driving technology, the research team developed a theoretical model based on established theories on planned behavior, technology acceptance, and personal goals. The findings showed that drivers’ intention to practice eco-driving has an indirect effect on their intention to use the system via the factor of perceived ease of use. The research team also explored how cognitive distraction while using an eco-driving system can be a potential barrier to acceptance. The intent is to put forward a solution to improve drivers’ usage of eco-driving by turning off guidance when the system detects that the driver is experiencing serious distraction. To investigate how to detect a driver’s cognitive distraction status when they are interacting with an eco-driving system, this project used a driving simulator and leveraged machine learning algorithms to classify drivers’ attentional states. The findings showed that the glance features played a more important role than the driving features in cognitive distraction.

Related Publications

policy brief

What Would it Take for Drivers to Adopt Eco-Driving Behaviors?

policy brief

Mobiliti—A New Tool to Guide Safer, More Equitable Traffic Management Strategies

Publication Date

September 4, 2025

Associated Project(s)

Matching Technique with Authority: A Study of How Local DOTs Can Narrow the Gap between their Network Management Authority and their Analytical Capacity

Author(s)

Rowland Awadagin Herbert-Faulkner, Jane Macfarlane, Karen Frick, Joan Walker

Areas of Expertise

Safety, Public Health, & Mobility Justice

View policy brief

Abstract

Regional studies examining transportation-related emissions and vehicle miles traveled (VMT) highlight the disproportionate safety and environmental impacts of passthrough traffic on vulnerable communities – traffic that travels through, but does not originate or end in these communities. Transportation practitioners and researchers have sought to address these inequities with locally tailored, context sensitive traffic management strategies (e.g., lowered speed limits on residential streets). However, decision makers must carefully consider the network-wide tradeoffs these strategies may introduce, which can complicate their effectiveness. This policy brief presents a network analysis method that is accessible to local and regional transportation agencies using Mobiliti, a high-performance traffic simulator currently available for research purposes. However, we demonstrate Mobiliti’s practical applications for transportation agencies. Developed by research scientists at Lawrence Berkeley National Lab, Mobiliti offers traffic assignment solutions and regional simulation capabilities, allowing for high-resolution, iterative exploration of road treatments and routing strategies. Analysts can manipulate network characteristics and vehicle behavior by adjusting parameters such as lane count, speed limit, and the percentage of vehicles, to dynamically optimize travel times. These capabilities can support transportation equity evaluations by giving network managers deeper insights into the mutual relationships between local and regional traffic dynamics and the resulting social impacts.

Related Publications

research report

Matching Technique with Authority: A Study of How Local DOTs Can Narrow the Gap between their Network Management Authority and their Analytical Capacity

policy brief

Navigating the Road to 100% Zero-emission Vehicle Sales: Policy and Research Needs

Publication Date

September 3, 2025

Associated Project(s)

Potential Challenges and Research Needs in reaching 100% Zero Emission Vehicle Sales in California: A Focus on Plug-in Electric Vehicles

Author(s)

Scott Hardman

Areas of Expertise

Zero-Emission Vehicles & Low-Carbon Fuels

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Abstract

More than 30 countries and several states and provinces (e.g., California, British Columbia) intend to reach 100% zero-emission vehicle (ZEV) sales by between 2025 and 2040. In 2024, 22% of global vehicle sales were plug-in electric vehicles (PEV), some large auto markets reached 10-30% in PEV sales, and some Nordic nations achieved sales of between 30% and 90%. Little research focuses specifically on challenges in reaching 100% ZEV sales. This policy brief is based on a literature review of the growing body of research on PEVs. The review focuses on understanding challenges in reaching 100% PEV sales and identifies current research questions on issues related to 100% PEV adoption.

Related Publications

published journal article

Supply-side challenges and research needs on the road to 100% zero-emissions vehicle sales

published journal article

Demand-side challenges and research needs on the road to 100% zero-emission vehicle sales

research report

Potential Challenges and Research Needs in Reaching 100% Zero Emission Vehicle Sales- A Focus on Plug-in Electric Vehicles

policy brief

Women Have Smaller Activity Spaces Than Men, Especially in Households with Children

Publication Date

September 3, 2025

Associated Project(s)

Exploring Gender and Travel Complexity

Author(s)

Fariba Siddiq, Zhiyuan Yao, Evelyn Blumenberg

Areas of Expertise

Travel Behavior, Land Use, & the Built Environment

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Abstract

Differences in how men and women travel have long been a focus in transportation research. Many studies have explored how socially-defined gender roles influence travel decisions and behaviors, consistently highlighting disparities between men’s and women’s travel patterns. For example, compared to men, women tend to make more caregiving and household-related trips, have shorter commutes, and are more likely to combine multiple destinations or purposes into a single tour. This body of research often concentrates on standard measures of travel—such as the number of trips taken, how far and for how long people travel, and travelers’ experiences— while also considering the influence of neighborhood design. However, travel patterns also are shaped by broader social structures and inequalities, which are not captured by these traditional measures. To better understand sex differences in travel, this study examined disparities in the size of an individual’s “activity spaces,” defined as the geographic area a person covers during daily activities, such as commuting, shopping, socializing, and leisure. The study draws on detailed trip data from the confidential California add-on to the 2017 National Household Travel Survey (NHTS), which provides the exact starting and ending locations for each trip taken on the survey day. The study estimates the size of each person’s activity space and compare patterns between men and women. It then explore how these differences relate to individual, household, and neighborhood characteristics.

research report

What Explains Trends in Orange County Transportation Authority Bus Ridership?

Publication Date

August 1, 2025

Associated Project(s)

What Explains Recent Trends in Orange County Transportation Authority Bus Ridership?

Author(s)

Farzana Khatun, Jean-Daniel Saphores

Areas of Expertise

Public Transit, Shared Mobility, & Active Transportation

View research report

Abstract

This report investigates whether the implementation in 2015 of California Assembly Bill 60 (AB 60) which requires the California Department of Motor Vehicles to issue a driver’s license to applicants who can prove California residency even if they are not legal US residents was responsible for subsequent declines in Orange County Transportation Authority (OCTA) bus ridership. Changing socioeconomic conditions, poor connectivity, poor service quality, and increased competition from TNCs are possible reasons behind this negative trend. Another potential cause is the implementation in 2015 of AB 60. In this context, this study examines the association between changes in OCTA bus ridership and the inception of AB 60 while controlling for differences in transit supply, socioeconomic variables, gas prices, multi-family rent, and single-family home value. To explain changes in monthly average weekday ridership, we estimated four route-level fixed-effect panel regression models different types of bus service. We analyzed ridership data for 2014 (just before AB 60) and 2015-2016 (the first two years after AB 60) for local, community, express, and station link routes. For local and community routes, we find decreases in the monthly OCTA bus ridership coefficients. For local routes, they range from a low of 1.7% in the Winter to a high of 7.7% in the Fall of 2015-16 compared to 2014. To counter this slide in ridership, OCTA may consider adjusting its service, increasing service frequency on selected routes, and exploring free or discounted pass programs.

Related Publications

policy brief

Did Extending Driver Licenses to Individuals Without Legal Presence Affect Transit Ridership in Orange County?

policy brief

Charging Ahead: How Income and Home Access Shape Electric Vehicle Adoption among Ridehailing Drivers

Publication Date

August 27, 2025

Associated Project(s)

Assessing the Potential Equity Impacts of the Clean Miles Standard (SB 1014) with an Emphasis on Part-Time Ridehail Drivers

Author(s)

Susan Shaheen, Elliot Martin, Mengying Ju

Areas of Expertise

Public Transit, Shared Mobility, & Active Transportation Safety, Public Health, & Mobility Justice

View policy brief

Abstract

Transportation network companies (TNCs), also known as ridehailing, such as Uber and Lyft, have contributed to increased vehicle miles traveled (VMT) and associated emissions in California’s urban areas over the past decade. In response, Senate Bill (SB) 1014 – the Clean Miles Standard – requires TNCs to achieve 90% electric vehicle (EV) miles traveled and zero greenhouse gas (GHG) emissions per passenger mile by 2030. The California Public Utilities Commission (CPUC) and the California Air Resources Board (CARB) oversee implementation and enforcement of these targets.

To understand the barriers and preferences for EV adoption among TNC drivers, the research team used a mixed-methods approach that integrates qualitative and quantitative data. This included 10 expert interviews, 8 driver group discussions, and a statewide survey of 436 full- and part-time TNC drivers conducted between May 2023 and April 2024. The survey gathered detailed information on drivers’ socio-demographic profiles, attitudes toward EVs, driving behaviors, and policy preferences, such as charging credits (i.e., a monetary incentive or prepaid allowance to offset the cost of EV charging activities and EV charging equipment) and EV purchase discounts (i.e., price reductions or instant rebates at the point of sale). In addition, the survey presented hypothetical decision-making scenarios to explore how factors such as income level, home charging access, and prior EV experience influence a TNC driver’s willingness to acquire an EV. Using statistical analysis, we estimated the most influential factors for EV adoption for full-time as well as part-time drivers. Then a “what-if” simulation was ran to explore how different combinations of incentives and driver characteristics might change the appeal of EV adoption.

Related Publications

published journal article