website
This website represents research led by Dr. Camila Correa-Julian at the UCLA Risk Sciences Institute, to explores how human drivers and vehicle automation systems interact during takeover events in Level 3 ADS, when responsibility for driving shifts from the system back to the human driver. This is a web page for sharing insights on this research and the publications.
policy brief
Ensuring equitable access to transportation services is critical for supporting the mobility needs of seniors and people with disabilities. In Contra Costa County, California, these populations face significant challenges in finding and using reliable and accessible transit—on demand microtransit services such as paratransit, and other multi-passenger/pooled shuttles or vans—due to the lack of a centralized up-to-date, customer-oriented informational system. These problems are compounded by the difficulties of arranging travel to multiple locations or scheduling trips with different mobility service providers (including paratransit agencies, community-based transit programs, and volunteer drivers programs).
To better understand the challenges faced by mobility-challenged individuals, the research team conducted a comprehensive examination of the existing accessible transit services in Contra Costa County. The research identified critical gaps and deficiencies that hinder the provision of efficient accessible transit services. The research team facilitated stakeholder meetings, consulted with organizations that provide or arrange accessible transit services, and conducted individual surveys to gather detailed insights into how critical data can best be collected, aggregated, disseminated and used to mitigate mobility barriers.
policy brief
The California Environmental Quality Act is designed to ensure consideration of environmental impacts of new development projects, but it can also invite litigation that can delay or derail projects, even those that may benefit the environment, such as transit oriented development (TOD). TOD aims to reduce vehicle miles traveled and greenhouse gas emissions by locating housing, jobs, and amenities near high-frequency public transit. But when CEQA requirements delay or discourage TOD, the result can be to push development to less accessible areas, leading to more driving, more emissions, and fewer housing options— undermining the very goals CEQA was meant to protect. In 2008, California passed SB 375, which included two CEQA streamlining provisions for TOD projects that meet specific criteria. This project investigated how much and where these provisions have been used. The research team also interviewed practitioners to assess how effective the provisions have been when used, and how streamlining could be improved to better facilitate TOD projects.
policy brief
The January 2025 Eaton and Palisades fires destroyed homes and roads across L.A. County. The experience revealed how urgently transportation systems must restore mobility and access after a fire or other major disaster—even though rapid transportation rebuilding can lock in unsafe road designs and miss chances to advance long-term resilience and community priorities.
research report
The January 2025 Eaton and Palisades fires revealed how urgently transportation systems must recover—and how quickly a rush to rebuild can entrench old risks. This report examines how collaborative community engagement can shape safer, more equitable transportation rebuilding and evacuation planning in Los Angeles. Drawing on literature, public agency records, and interviews with transportation professionals, fire survivors, and community leaders, the research explores whether California’s Transformative Climate Communities (TCC) model can guide post-fire recovery. Findings show that rapid, like-for-like restoration often precludes safer designs and multimodal options; effective rebuilding requires cross-agency coordination, integration of evacuation needs into transportation planning, and trauma-informed engagement with residents. Community-based organizations can foster trust and inclusion, but need compensation and support to participate meaningfully. The TCC model offers adaptable structures—collaborative visioning, shared governance, and flexibility—that could strengthen post-disaster recovery if scaled to faster timelines. This research calls on policymakers and practitioners to embed community priorities in transportation decisions, align funding to sustain partnerships, and rebuild for long-term resilience rather than short-term restoration.
research report
Wildfires pose threats to health due to exposure to wildfire smoke and other toxic debris. Those who rely on public transit are potentially more exposed to these threats, yet little is known about how transit riders navigate this increased exposure amid evacuation and displacement. In this study the research team examines the exposures of transit riders during a fast-moving wildfire emergency, the 2025 Los Angeles wildfires. The team conducted a mixed methods study of transit riders, drawing from a survey and semi-structured interviews of riders sampled from Transit, a widely used real-time bus tracking app for transit riders. Preliminary findings show that during the wildfire, many transit riders relied on informal rides, public transit, or walking to evacuate, leading to longer evacuation times and heightened exposure to smoke. Survey-linked air quality data revealed that nearly half of Black and Latino respondents experienced “unhealthy” PM2.5 concentrations at their homes on peak smoke days, a burden echoed in widespread reports of respiratory and mental health impacts. Riders adopted protective strategies such as wearing masks and avoiding transit when possible, but those without cars faced limited options. These results underscore the need for transportation planners and emergency managers to design evacuation and communication strategies that explicitly support transit-reliant and car-less households.
policy brief
Many suburban and rural communities struggle to provide affordable, efficient public transit. Some have replaced underused fixed-route, fixed-schedule public transit with on-demand, door-to-door microtransit services. In some cases, microtransit has provided better service, though it’s only economical when most trips serve multiple riders. In low-demand areas, limited ride consolidation drives costs sharply upward– often exceeding $50 per rider trip. Transportation Network Companies (TNCs), like Uber and Lyft, could help fill this gap. They already provide door-to-door service with extensive driver networks and low overhead. Yet most public-private pilot programs using TNCs to supplement or replace traditional transit have failed to last beyond their initial funding periods.
policy brief
The California Environmental Quality Act (CEQA) requires lead agencies to evaluate the environmental impacts of major projects, including highway expansion projects, and to mitigate those impacts to the extent feasible. In 2013, SB 743 (Steinberg) changed how transportation impacts are evaluated by shifting the performance measure from traffic delay to vehicle miles traveled (VMT), a measure of total driving. This change reflected evidence that the metric of VMT captures the influence that transportation projects have on driving behavior and its related environmental and social impacts, such as greenhouse gas emissions, air pollution, safety, and public health.
How have lead agencies implemented the requirement to analyze and mitigate VMT induced by highway expansion projects? To better understand how SB 743 has affected highway expansion projects in practice, the team reviewed state regulation and guidance and evaluated the Environmental Impact Reports (EIRs) for the six highway expansion projects that have started the environmental review process since the California Department of Transportation (Caltrans) adopted guidance in 2020 to implement SB 743. In this brief, the research team focuses on how lead agencies propose to mitigate any increases in VMT from each of the six highway expansion projects, including the measures proposed, the extent to which mitigation reduces VMT, the cost associated with mitigation, and sources of funding for VMT mitigation.
research report
This report develops a transportation hydrogen roadmap for California projected to 2045, building on previous UC ITS work, partly in cooperation with the ARCHES hydrogen hub for analysis of trucks, ports, and aviation. This study adds these modes as well as rail systems and fuel-cell light-duty vehicles, to provide a comprehensive transportation sector map of potential hydrogen use. The report focuses on a scenario of high adoption of hydrogen-fueled transport, where the modes and sectors covered 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, 20% by light-duty vehicles, and 20% by other modes, notably shipping and aviation. These shares remain similar out to 2045. Trucking remains the dominant driver of hydrogen demand throughout the projection period. Shipping, aviation, and rail are not expected to account for an increasing share of demand in these scenarios. The study includes a jobs analysis, led by UCLA, that estimates that the 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 for the system to be self-sustaining, using many hundreds of tonnes per day by 2040.
research report
This study examines whether co-locating stations for light-duty zero emission vehicles (ZEVs) with stations for heavy-duty ZEVs would increase network coverage and improve resiliency to help California achieve its targets for widespread ZEV adoption. The study separately models of siting light-and heavy-duty at the same locations vs. separate locations for (i) electric charging stations and (ii) hydrogen refueling stations. The results indicate electric charging stations in California are being used at only 13% of total capacity. Building out and optimizing the locations of light-duty electric vehicle stations will results in greater demand met and resiliency than will co-locating these at heavy-duty charging stations. On the other hand, co-location of hydrogen refueling stations for light duty vehicles at sites for heavy-duty vehicle stations may increase demand met, network resiliency, and adoption rates of light-and heavy-duty fuel cell electric vehicles. These adoption rates are constrained by the current infrastructure.
