Institute of Transportation Studies at UC Berkeley

In the San Francisco Bay Area, earthquake damage to a small number of critical transportation facilities can produce regionwide mobility impacts. This report evaluates the Berkeley Hills Tunnel, a key Bay Area Rapid Transit (BART) cross-hills connection, using an integrated model that links tunnel seismic performance to transportation consequences during disruption and recovery. The model couples scenario-based seismic assessment of the tunnel with screening-level fragility for substitute corridors and propagates the resulting time-dependent capacity states through a transportation simulation. At a representative recovery-stage demand of 25 percent of normal, mean cross-hills travel time rises from about 9 minutes in the mildest scenario (327-year return period) to about 41 minutes in the most severe (654-year). In that severe case, a fully subscribed bus bridge can lower the mean cross-hills travel time by up to 30 percent. Uncertainty quantification identifies recovery-stage demand as the dominant source of travel-time variance and shows that unfavorable capacity combinations can nearly double travel time relative to the central estimate. Disruption falls disproportionately on transit-dependent travelers, who either endure longer travel times or pay an extra travel fee. Agencies can use the workflow to assess disruption impacts and identify likely bottlenecks, compare recovery-stage operational strategies, and target equitable service for affected populations.

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.

This report investigates jaywalking laws in connection with traffic safety, racial equity, and street design, focusing on California. It traces the concept of "jaywalking" to an early 20th-century auto industry campaign to shift safety responsibility from drivers to pedestrians. By analyzing national and California pedestrian injury and fatality data (2009–2022) alongside California Racial and Identity Profiling Act (RIPA) police stop data (2018–2022), the study describes demographic disparities in both pedestrian crashes and law enforcement of jaywalking. It also documents recent legislative efforts in California and other states and cities to decriminalize or reform jaywalking enforcement. Findings show that pedestrian fatalities reached a 40 year high in 2022, with California’s rates consistently exceeding the national average. Significant racial and economic disparities exist: Black pedestrians experience fatality rates multiple times those of White pedestrians, and lower-income neighborhoods suffer disproportionately. RIPA data further reveal that jaywalking-related police stops disproportionately affect Black pedestrians. These disparities are likely driven by the built environment—such as wide arterials and sparse crosswalks—which incentivizes mid-block crossings, particularly in under-invested communities. The report also examines California’s Assembly Bill (AB) 2147 (2022), which partially decriminalized jaywalking by limiting enforcement to cases of "immediate hazard." It concludes by recommending continued monitoring of enforcement and safety data to track AB 2147’s impact, alongside collecting built environment data to better contextualize racial and economic disparities in pedestrian outcomes.

California’s transition to electric vehicles (EVs) requires more than additional charger counts. Public charging must be accessible, affordable, and reliable where people actually live and travel. This report presents a geospatial dashboard and time-series toolkit for the nine Bay Area counties that maps public charging stations, tracks price and charging-port status at 10-minute intervals, and identifies disadvantaged community (DAC) census tracts using the joint U.S. Department of Energy/U.S. Department of Transportation/National Electric Vehicle Infrastructure (DOE/DOT/NEVI) framework. The tool reports charger availability, utilization, pricing, reliability, and average session cost, and supports equity metrics such as ports per 1,000 residents or renters, travel time to a direct-current fast charger, and tract-levelcomparisons between DAC and non-DAC areas. It also supports early screening of sites for Level-3 fast chargers by identifying locations that appear feasible from the grid standpoint. The result is a practical planning tool that allows agencies to monitor conditions continuously without field surveys and to target investments toward areas of greatest need.

This report presents a set of proposed open data specifications for the development of an Operational Data Portal (ODP) to support customer-oriented “smart” apps for travelers with special needs, particularly seniors and people with disabilities, in Contra Costa County. The ODP would aggregate and organize data from various mobility service providers, individual riders, and community organizations to be accessed by software developers of digital trip planners, trip booking and scheduling services, passenger feedback mechanisms, and service performance evaluation tools. The report concludes that the establishment of an open data platform along with supporting applications will improve the riderexperience and facilitate operating efficiency and coordination among accessible transit providers. It recommends further research to align the proposed data specifications with emerging transportation data standards, enhance the integration of unstructured data, and develop inclusive systems for customers with limited access to smart devices.

The Vehicle Weight Safety Study provides supporting analysis for the California Transportation Commission’s study on therelationship between vehicle weight and road user injury and roadway degradation required by Assembly Bill (AB) 251, which was signed by the Governor in October 2023. To inform the work of the CTC, this report summarizes trends of road user injuries and fatalities in California and potential factors contributing to these trends (Chapter 2); summarizes trends in vehicle weight, size, and height for registered vehicles in California (Chapter 3); documents the landscape of policy solutions focused on vehicle size that might address California’s road user injuries and fatality challenge (Chapter 4); analyzes the impact of potential weight-based fees on consumer vehicle purchasing behavior (Chapter 5); and, analyzes the relationship between shifts in passenger vehicle weight and degradation of road infrastructure (Chapter 6).

The CA-LCA-H2 tool performs a cost and greenhouse gas and criteria air pollutant emissions assessment for a hydrogen project in California by selecting the operating region and mode of production and distribution of the hydrogen through to a fuel cell trucking use case. The cost of clean hydrogen production can change significantly from the choice of production method due to the respective energy and capital costs, and in the case of electrolysis, the electricity source. The regional variations in the electricity mix can significantly affect the carbon intensity of the hydrogen produced. These components then contribute to the potential effectiveness of hydrogen as a low-carbon fuel for the use case assessment.

This study addresses the persistent challenge of delivering cost-effective, high-quality on-demand transit in low-density communities. Traditional microtransit services often struggle in such areas due to high fixed costs and limited opportunities to consolidate trips, while community partnerships with transportation network companies (TNCs) like Uber and Lyft are typically avoided due to concerns over data transparency and limited community control. To bridge this gap, we propose a new business plan for cooperative TNC partnerships, in which a community-appointed service manager coordinates trip requests, distributes financial incentives to attract drivers to the community from nearby high-demand areas, and leverages the TNC’s existing digital infrastructure for driver dispatch and routing. We evaluate this business plan through case studies of three Northern California communities presently served by microtransit, comparing microtransit’s measured performance against the predicted performance of a TNC operating under the proposed business plan using a simple metric that does not depend on the specific design of the transit system. Results show that TNCs can deliver higher levels of service and higher driver wages in all three communities and were more cost-effective than microtransit in two of the three. Applying the metric across California reveals that many communities with microtransit, and numerous other communities presently underserved by transit, would likely benefit from switching to TNC partnerships. This suggests that a large opportunity exists for using TNC partnerships to provide mobility in areas where other forms of transit are less effective.

This report develops a transportation hydrogen roadmap for California projected to 2045, building on previous UC ITS work, in part for the ARCHES hydrogen hub for trucks and ports. This study adds modes such as airports, aircraft, rail systems, and fuel-cell light-duty vehicles. Based on a scenario of high adoption of hydrogen-fueled transport, these modes and sectors would use 1000 tonnes/day of hydrogen by 2035 and 5000 tonnes/day by 2045. To 2035, about 40% of the expected growth occurs in heavy-duty trucking. Another 20% is used by other truck types, about 20% by light-duty vehicles, and 20% by other modes, notably shipping and aviation. These shares remain similar to 2045. Trucking remains the dominant driver of demand. Shipping, aviation, and rail are not anticipated to account for an increasing share of demand in the scenarios in this study. This hydrogen fuel system would support around 6,000 jobs per year. Hydrogen vehicle adoption will depend on strong policy support, coordination of planning and investments, and rapid scale up to reach a hydrogen system that can be self-sustaining, on the order of hundreds of tonnes per day by 2040.

Top-down transportation planning practices have historically ignored the needs and concerns of low-income communities of color, which can lead to residential and commercial displacement as public investments increase land values and rents. The concept of mobility justice centers the needs of communities that have historically been excluded from transportation planning decisions. We partnered with community groups to examine two transportation planning projects in the Bay Area using collaborative research methods. The first was a retrospective analysis of the East Bay Bus Rapid Transit project in East Oakland that reflects the harms of top-down planning. The second study examined the City of Richmond’s Transformative Climate Communities projects, a more collaborative approach to planning with low-income communities involved at every stage. We find that the top-down planning model employed in the East Oakland case study resulted in significant health, safety, and displacement impacts that could have been avoided. The Richmond case study shows project changes occurring as a direct result of using mobility justice principles.