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Open Access Publications from the University of California

The Institute of Transportation Studies at UC Berkeley has supported transportation research at the University of California since 1948. About 50 faculty members, 50 staff researchers and more than 100 graduate students take part in this multidisciplinary program, which receives roughly $40 million in research funding on average each year. Alexandre Bayen, Professor of Civil and Environmental Engineering and Professor of Electrical Engineering and Computer Science, is its director.

Cover page of Subsidizing Transportation Network Companies to Support Commutes by Rail

Subsidizing Transportation Network Companies to Support Commutes by Rail

(2024)

We explore how rail transit’s first- and last-mile issue might be addressed by partnering with transportation network companies (TNCs) like Uber and Lyft. The goal is to lure high-income commuters to shift from cars to TNCs and rail. We also explore how rail and TNC partnerships can improve travel for low-income commuters who currently rely on low-frequency bus service. We parametrically test subsidizing TNC fares for feeder services in the San Francisco Bay Area in

an idealized fashion. Inputs such as the residents’ value of time and vehicle ownership were taken from various local data sources. The communities that were selected for our study are served to different degrees by the BART rail system. We found that the optimal policy must be tailored to the characteristics of the community it serves. In dense, walkable communities with strong bus service near rail stations, TNC subsidies should be targeted to less-accessible neighborhoods and low-income commuters to not compete with bus transit and active modes like walking. For lower-density communities with limited dedicated bus feeder service, TNC subsidization can be applied more broadly, although disincentives, like increasing rail parking fees, must be considered carefully, because they can induce commuters to drive directly to work instead. We conclude with a discussion of how subsidies might be covered by reallocating existing resources in different ways.

Cover page of Advanced Air Mobility: Opportunities, Challenges, and Research needsfor the State of California (2023-2030)

Advanced Air Mobility: Opportunities, Challenges, and Research needsfor the State of California (2023-2030)

(2024)

Advanced air mobility (AAM) is a broad concept that enables consumers access to air mobility, goods delivery, and emergency services through an integrated and connected multimodal transportation network. AAM can provide short-range urban, suburban, and rural flights of about 50-miles and mid-range regional flights up to a several hundred miles. State law delegates responsibility for oversight in aviation primarily to the California Department of Transportation (Caltrans). This white paper presents an overview of the state of the market, such as the aircraft under development and forecast market growth and discusses factors that could facilitate the development of AAM or pose risks to its deployment or to the public, including the safety and the regulatory environment, airspace and air traffic management, security, environmental impacts, weather, infrastructure and multimodal integration, workforce and economic development, social equity, and community engagement and social acceptance. It concludes by recommending actions that Caltrans and other state agencies can take to facilitate the development of AAM.

Cover page of Charging up the Central Coast: Policy solutions to improve electric vehicle charging access in Watsonville

Charging up the Central Coast: Policy solutions to improve electric vehicle charging access in Watsonville

(2023)

California's goal to eliminate internal combustion engine sales by 2035 poses challenges for lower- and moderate-income residents, hindering their access to electric vehicles (EVs). Barriers include limited EV charging stations, exacerbated by lower home ownership and inadequate grid infrastructure in lower-income communities. To address this, UC Berkeley School of Law's Center for Law, Energy & the Environment (CLEE) partnered with the City of Watsonville. Due to its location, demographics, and ambitious policy goals, Watsonville represents a potential model and case study for other cities around the state grappling with how to boost EV charging infrastructure. CLEE conducted stakeholder interviews and a convening in Watsonville in May2023, and developed a set of policy recommendations for both state and local entities to accelerate investment in EV charging infrastructure in Watsonville, which could inform other cities facing similar challenges and seeking to meet state targets and residents’ needs.

Cover page of Policies to Improve Transportation Sustainability, Accessibility, and Housing Affordability in the State of California

Policies to Improve Transportation Sustainability, Accessibility, and Housing Affordability in the State of California

(2023)

This report presents analytical review of empirical research on the interactions between housing availability and production, and travel behavior, accessibility, land use policies, and transportation policies. It identifies lessons from this review for California state legislative efforts to improve housing and transportation linkages, and to increase both transportation sustainability and housing affordability. Relevant California state efforts include legislation to influence parking standards; to require up-zoning near transit stations; to influence regional housing and transportation planning goals; and to change environmental review to focus on reducing vehicle miles traveled instead of accommodating road traffic.

Cover page of Mitigating Exposure and Climate Change Impacts from Transportation Projects: Environmental Justice-Centered Decision-Support Framework and Tool

Mitigating Exposure and Climate Change Impacts from Transportation Projects: Environmental Justice-Centered Decision-Support Framework and Tool

(2023)

California must operate and maintain an effective and efficient transportation infrastructure while ensuring that the health of communities and the planet are not compromised. By assessing transportation projects using a life-cycle perspective, all relevant emission sources and activities from the construction, operation, maintenance, and end-of-life phases can be analyzed and mitigated. This report presents a framework to assess the life-cycle human health and climate change impacts from six types of transportation projects: (1) Roadways; (2) Marine ports; (3) Logistical distribution centers; (4) Railyards; (5) Bridges and overpasses; and (6) Airports. The framework was applied using an integrated model to assess fine particulate matter (PM2.5) and greenhouse gas (GHG) emissions, noise impacts, and monetized damages (Value of Statistical Life, Social Cost of Carbon) from two case studies: routine resurfacing and vehicle operations on road segments within the San Francisco Bay Area using 2019 data, and annual marine, cargo, rail, trucking, and infrastructure maintenance operations at the Port of Oakland in 2020. The results suggest that emission sources in a project’s supply chain and construction (material production and deliveries, construction activities, fuel refining) can significantly contribute to the full scope of impacts from transportation systems. Equitable mitigation policies (e.g., electrification, pollution control technologies) need to be tailored to address the sources that impact communities the most.

Cover page of New Data and Methods for Estimating Regional Truck Movements

New Data and Methods for Estimating Regional Truck Movements

(2023)

This report describes how current methods of estimating truck traffic volumes from existing fixed roadway sensors could be improved by using tracking data collected from commercial truck fleets and other connected technology sources (e.g., onboard GPS-enabled navigation systems and smartphones supplied by third-party vendors). Using Caltrans District 1 in Northern California as an example, the study first reviews existing fixed-location data collection capabilities and highlights gaps in the ability to monitor truck movements. It then reviews emerging data sources and analyzes the analytical capabilities of StreetLight 2021, a commercial software package. The study then looks at the Sample Trip Count and uncalibrated Index values obtained from three weigh-in-motion (WIM) and twelve Traffic Census stations operated by Caltrans in District 1. The study suggests improvements to StreetLight’s “single-factor” calibration process which limits its ability to convert raw truck count data into accurate traffic volume estimates across an area, and suggests how improved truck-related calibration data can be extracted from the truck classification counts obtained from Caltrans’ WIM and Traffic Census stations. The report compares uncalibrated StreetLight Index values to observed truck counts to assess data quality and evaluates the impacts of considering alternate calibration data sets and analysis periods. Two test cases are presented to highlight issues with the single-factor calibration process. The report concludes that probe data analytical platforms such as StreetLight can be used to obtain rough estimates of truck volumes on roadway segments or to analyze routing patterns. The results further indicate that the accuracy of volume estimates depends heavily on the availability of sufficiently large samples of tracking data and stable and representative month-by-month calibration data across multiple reference locations.

Cover page of Strategies to Preserve Transit-accessible Affordable Housing in Southern California

Strategies to Preserve Transit-accessible Affordable Housing in Southern California

(2023)

This report highlights risk and prioritization factors for housing developments with expiring affordability protections, focused on preserving transit-accessible affordable housing. It presents a regional framework for identifying and preserving subsidized affordable housing in the Southern California Association of Governments (SCAG) region (Los Angeles, Imperial, Orange, Riverside, San Bernardino, and Ventura counties). First, we analyze data from the California Housing Partnership (CHPC) and the National Housing Preservation Database (NHPD) to understand risk factors for expiring housing units, and design a prioritization tool for entities in the region to use when prioritizing developments to focus preservation and anti-displacement efforts. Second, we highlight affordable housing preservation policy solutions and characteristics unique to the Southern California context. Third, we draw on the strategies and experiences of other jurisdictions in the United States with experience strategizing around affordable housing preservation efforts to present key lessons and takeaways.

Cover page of Zero-Emission Bus Implementation Guidebook for California Transit Fleets

Zero-Emission Bus Implementation Guidebook for California Transit Fleets

(2023)

Transit bus operations in California are experiencing new challenges due to economic conditions and the ongoing global pandemic. A confluence of factors has created a focus on this critical public-needs serving industry, due to state and local efforts to reduce emissions of pollutants and climate-changing gases. Transit bus operations in California provide essential and additional useful services that offer critical mobility to needy populations (elderly and handicapped) as well as many other groups for whom transit buses provide the most economical, convenient, and low-emission options. To address the role of transit bus operations in meeting California’s aggressive greenhouse gas (GHG) and emissions, the California Air Resources Board (ARB) has implemented an ambitious Innovative Clean Transit (ICT) regulation that requires all public transit agencies to gradually transition to a 100 percent zero-emission bus (ZEB) fleet.1 Beginning in 2029, 100% of new purchases by transit agencies must be ZEBs, with a goal for a full transition by 2040. Prior to that 25% of purchases of new buses must be ZEBs in 2023-2025 for large transit agencies, rising to 50% in 2026-2028. For smaller transit agencies, defined as those with less than 100 buses in annual maximum service, there is no requirement for 2023-2025 and the requirement for 2026-2028 is 25%, but the 100% ZEB purchase requirement starting in 2029 applies to all agencies.

Cover page of California’s Freeway Service Patrol Program: Management Information System Annual Report Fiscal Year 2020-21

California’s Freeway Service Patrol Program: Management Information System Annual Report Fiscal Year 2020-21

(2022)

The Freeway Service Patrol (FSP) is an incident management program implemented by Caltrans, the California Highway Patrol and local partner agencies to quickly detect and assist disabled vehicles and reduce non-recurring congestion along the freeway during peak commute hours.  The first FSP program was piloted in Los Angeles and was later expanded to other regions by state legislation in 1991.  As of June 2020, there were sixteen participating FSP Programs operating in California, deploying 305 tow trucks and covering over 1,900 (centerline) miles of congested California freeways.

 

The purpose of this research project was to evaluate the effectiveness of the Caltrans FSP program in reducing incident durations and removal of other obstructions that directly contribute to freeway congestion for Caltrans fiscal year 2020-2021.  The project provides valuable information to agencies managing the FSP program so that resources are distributed within the various statewide FSP operations in the most efficient and cost-effective manner possible.  The tools used and the operational performance measures provided by this research effort will significantly contribute on the ongoing agencies’ efforts to improve the efficiency and effectiveness of the FSP program.

Cover page of Can Rebates Foster Equity in Congestion Pricing Programs?

Can Rebates Foster Equity in Congestion Pricing Programs?

(2022)

Congestion pricing improves economic efficiency, but it may lead to inequitable outcomes. A key policy priority in California is identifying ways to avoid the hardship of congestion pricing on low income or other vulnerable populations. This study uses data from a congestion pricing experiment in the Seattle metro area to examine the feasibility of using revenue from congestion pricing to compensate those harmed by the policy. Results indicate that the initial burden of congestion pricing is highly inequitable, with the lowest income drivers paying an average of 7 percent of their weekly income in congestion charges. There are also considerable differences in burdens within income groups. We show that policymakers face a tradeoff in ameliorating these two types of unequal burdens. Returning an equal fraction of the toll revenue to all drivers can make a policy progressive on average, but doing so leaves many drivers either overcompensated or under-compensated. We then show that while compensation packages based on basic demographic information could improve targeting, many low-income drivers would be left with large proportional burdens because of the fundamental difficulty in predicting individual-level tax burdens. Survey data on travel behavior from Seattle and California metro areas show that the difficulty of designing equitable transfers would be similar in the California metro areas most likely to consider adopting some form of congestion pricing.