Institute of Transportation Studies at UC Berkeley

The escalating number of injuries and fatalities among cyclists is a pressing safety concern. In the United States, communities are actively seeking strategies to boost cyclist safety, with some states implementing bike-specific policies, such as stop-as-yield laws, to support cyclists. Stop-as-yield laws allow cyclists to treat stop signs as yield signs. The laws are not yet widely implemented, and their potential safety impact is a subject of debate among transportation experts and advocates. This study investigates how stop-as-yield laws can positively or negatively affect safety and provides insights and guidelines for California policymakers and safety practitioners if the law passes in California. We collected cyclist data from five states that have enacted stop-as-yield laws—Idaho, Arkansas, Oregon, Washington and Delaware—and data from some of their contiguous states without such legislation. Using an observational before-after study with comparison groups at the state level, the research examined changes in cyclist crash frequencies after the laws were implemented. Additionally, a random-effects negative binomial regression model with panel data was employed to estimate a law’s overall impact. The results did not indicate a significant change in cyclist crashes among the states with stop-as-yield laws.

In the United States, public transit agencies are increasingly growing interested in deploying open-loop payment systems for public transit fare payments. This interest is based on the benefits these systems can offer, from faster boarding times to the potential of attracting more riders.  Open-loop fare payment systems’ popularity is evidenced by the growing number of American public transit agencies who have deployed them; most of whom (63%) are located in California. The overlap between public transit riders who are both transit-dependent and financially excluded (i.e., have no or limited access to financial services) creates the opportunity for public transit agencies deploying open-loop payment systems to leverage these systems to increase financial service access for transit dependent, financially excluded riders. Individuals who are both transit-dependent and financially excluded are typically low-income, identify as part of a racial or ethnic minority group, immigrants, and/or women. As a result of these demographic characteristics, this work focuses on these populations. Additionally, financial inclusion, especially for these populations, is a critical step for economic and social mobility in the United States. This research focuses on California and explores how to leverage public transit agency deployment of open-loop payment systems to increase riders' financial service access. This research is comprised of a literature review, expert interviews (n=11), population needs mapping, and partnership proposals. In general, public transit agencies can strategically work with financial sector-based partners who focus on serving the transit agencies' priority rider groups. 

Located within the seismically active Pacific Ring of Fire, California's transportation infrastructure, especially in the Bay Area, is susceptible to earthquakes. A review of current research and stakeholder interviews revealed a growing awareness of emergency preparedness among local jurisdictions and transit agencies in recent years. However, many have yet to formalize and publish their recovery plans. This study introduces an agent-based multimodal transportation simulation tool to enhance post-earthquake transportation resilience. Integrating a road network simulator with a metro system simulator, the tool employs an optimized Dijkstra-based algorithm to calculate optimal routes, travel times, and fares. A case study is conducted for the East Bay, using the simulator to gauge the impact of a compromised Bay Area Rapid Transit (BART) system. The results suggested that original BART passengers could face either longer commute times or higher costs during the recovery phase of a major earthquake without appropriate policies. Such outcomes could disproportionately burden low-income riders, affecting their mobility and overall travel time.

Suburban areas have lower density development than urban areas, which may make them less accessible for the growingpopulation of low- and moderate-income suburban residents, particularly those without a personal vehicle. This research examines factors that lead these households to move to suburban areas and identifies accessibility barriers they face. We use a mixed-methods approach with Public Use Microdata Sample (PUMS) data from the U.S. Census, online/in-person surveys (n=208), and interviews conducted in English and Spanish (n=25) with households in Contra Costa County with an income of less than $75,000. To understand key differences in housing and transportation choices between urban and suburban residents, these data were compared to survey and interview data from low-income Oakland residents from 2020-2021. We found that low- and moderate-income households choose to live in suburbs due to rising rents and otherrequirements (e.g., credit score, rental history) in urban areas, and a desire for home ownership and safer environment for children. Yet lack of tenant protections is leaving them vulnerable to rising rents in suburban areas. Transportation costs are higher in suburbs due to longer commutes and higher reliance on personal vehicles. Despite higher levels of carownership in the suburbs, households often go without a car due to maintenance issues or inability to make car payments. When faced with the lack of an automobile, suburban households have few quality transportation alternatives.

Robotaxi services, or rideshare operated by autonomous vehicles, present an opportunity for independent and convenient transportation for people with disabilities. The proliferation of robotaxis in California has been met with mixed reactions from the disability community. To better understand perceptions of and expectations for robotaxis, this report uses semi-structured interviews with representatives from disability advocacy organizations. For many people with disabilities, especially for people with intellectual, developmental, and/or physical disabilities, robotaxis are inaccessible. Given the intricacies of accommodating a wide audience, not all interviewees were confident that robotaxi design and programming will be inclusive. Some interviewees trusted that autonomous vehicle companies will independently pursue accessibility features in their robotaxis. Other interviewees regarded statewide accessibility standards as essential to ensure accessibility. Overall, interviewees shared that people with disabilities want to be included in the process of designing, testing, and regulating robotaxis.

Implications for accessible robotaxi governance in California is presented, with an emphasis on wheelchair access, considering impact on public transportation service, and centering people with disabilities. Interviewees also discussed ideal accommodations that would allow a broad audience to request a ride, board the robotaxi, communicate with the operation system, and exit the vehicle. These findings may be useful to AV companies as they consider how robotaxis can accommodate people with a variety of disabilities.

Amidst increasing investments in cycling infrastructure in California, trends continue to demonstrate that women from low-income communities of color are underrepresented as cyclists. I argue that prevailing bicycle justice movements have neglected the intersectional needs of women from Black, Indigenous, and People of Color (BIPOC) communities by centering the ‘white, lycra-clad male’ and his commute needs within organized bicycling advocacy. Further, contemporary bicycle planning does little to investigate the barriers and joys related to cycling, as they are experienced by these women. This article draws from nine in-depth interviews with women of color in Oakland, California, to identify the racial and gendered barriers that influence the decision to cycle and whether only the construction of cycling infrastructure is enough to overcome these social barriers. Findings suggest that the fear of traffic injuries, coupled with the perceived and actual risk of victimization, sexual harassment, and racial violence discourage women of color from cycling. The concerns are further exacerbated by systemic failures of the city, including housing unaffordability, increasing income inequality, and the politics of gentrification. This suggests that bicycling planning must address more complex social factors besides infrastructural ones, create more opportunities for women of color to be included in bicycle planning and advocacy spaces, and help destigmatize cycling by increasing the visibility of BIPOC women as cyclists. I conclude this article by offering suggestions for practitioners and policymakers that might help reduce social barriers to cycling for women of color.

California boasts nine national parks that are home to a plethora of recreational, cultural, and professional opportunities. It is no surprise that national parks draw in millions of recreational and non-recreational trips from across the country and internationally, however how visitors choose to arrive at these federal lands is a major consideration for land management, policy, and infrastructure decisions. According to the National Park Service’s Visitor Use Statistics, an overwhelming majority of visitors arrive by automobile. Alternative transportation options to national parks in California may increase visitor diversity and encourage the modal shift away from car travel. Additionally, transportation infrastructure has the potential to take up more natural spaces in national parks as population growth and recreational popularity increases in the coming years. Roadway widening, repaving, and other disruptive events can have negative impacts on adjacent ecosystems and communities, as well as contribute to public health issues. In this report, the existing conditions of transit to national parks in California are examined in relation to census tract-level sociodemographic and origin-destination data to reveal the spatial distribution of visitor origins and gaps in national park accessibility. From an equity perspective, findings suggest that median household income is proportional to the network distance between a given trip origin and national park destination, and household vehicle access and race are strongly correlated with national park visitation. By examining the current transit network to national parks, select characteristics of park visitation, and demographics of these visitors, this research aims to reveal opportunities for expanded transit connectivity to California’s national parks. Recommendations are presented to provide guidance to decision makers in the realm of transportation access to recreational spaces.

Low-income communities of color in formerly redlined neighborhoods face persistent racial disparities and inequities in pollution exposure, access to transportation and safe streets, and inadequate provisions for health, safety, stable housing, clean air, education, and employment. In the process of attempting to remedy such disparities through major transportation infrastructure and access improvements, residents who are intended to benefit from expanded transportation access and options are often placed at increased risk of harmful displacement, gentrification, and environmental injustice impacts. This research project employs a case study of the International Boulevard Bus Rapid Transit (BRT) project in East Oakland, guided by Community Based Participatory Action Research (CBPAR) principles, to investigate specific traffic safety and racialized displacement impacts from the project and considers potential solutions towards protecting residents and preventing harmful byproducts of major transportation projects. In collaboration with a Community Advisory Council (CAC), a quantitative analysis of collisions along the corridor and demographic changes in select East Oakland neighborhoods was conducted. The results show evidence of increased fatality and injury collisions along the corridor at the start of construction of the BRT and after opening of the service as well as continued trends of gentrification and displacement in many East Oakland neighborhoods along the corridor. It is inconclusive with this research if there is a causal link between the BRT project and exacerbated displacement trends in nearby neighborhoods. Further qualitative research is needed to ground-truth and understand more fully the indirect land and housing market impacts of the BRT project.

The Universal Basic Mobility (UBM) pilots in Oakland and Los Angeles, launched in 2021, were innovative initiatives to address transportation equity and access issues in historically underserved communities. These experimental programs examined the impact of providing flexible transportation benefits to low-income residents. However, the current program designs fall short of achieving accessibility and sustainability objectives. Instead, they serve as initial steps in exploring UBM as a potential transportation equity strategy. The report explores the motivation behind local agencies initiating UBM pilots despite existing transportation benefit initiatives, and provides insights from program practitioners on the challenges and opportunities in UBM implementation.

As jurisdictions update their High Injury Networks, discrepancies between the initial and updated HINs are to be expected. However, this lack of stability and consistency can negatively impact the prioritization of limited resources. In order to mitigate known issues with crash data underreporting and statistical biases, I examined strategies for utilizing data on underlying roadway characteristics to augment traditional collision analysis.

Using the City of Oakland as a case study city, I assessed the stability of the pedestrian High Injury Network across two consecutive five-year periods (2012-2016 and 2017-2021), created with the same methodology. I found that the two HINs identified similar segments, particularly along arterials, but were less consistent in identifying the segments’ start and end points due to variation in crash data. I propose a methodology for finalizing High Injury Network extents based on segment characteristics (number of lanes, posted speed limit, and functional classification), and intersection characteristics (traffic signal presence and estimated pedestrian volumes). Applied to the Oakland case study, this approach results in a High Injury Network that is more stable over time, more focused (fewer street miles), and captures a higher percentage of fatal and severe crashes. This approach has the potential to smooth over inconsistencies in crash reporting, reduce the frequency of network updates needed, and shift High Injury Networks from being reactive to more proactive.