On Board With... Dr. Susan Shaheen, CARB Member and UC Berkeley Professor

Transit California interviewed Dr. Susan Shaheen, who serves as a Member of the California Air Resources Board (CARB), Professor of Civil and Environmental Engineering at UC Berkeley, co-director of the Transportation Sustainability Research Center (TSRC) of the Institute of Transportation Studies-Berkeley, and director of the UC ITS Resilient and Innovative Mobility Initiative.  


Transit California: You were appointed to CARB, the state’s lead agency for fighting climate change and addressing air pollution, by Governor Newsom in January 2023 as the Automotive Member.  What are some of your expectations and priorities for transit-related issues that may come before the Board during your term? 

Thank you for the opportunity to be featured in this issue of Transit California and respond to your thoughtful questions. I greatly appreciate the chance to connect since my recent appointment and confirmation to the California Air Resources Board. 

Public transit plays a critical role in achieving California’s climate, air quality, and equity goals by reducing emissions and vehicle miles traveled (VMT). The 2022 Scoping Plan, California’s roadmap to reaching carbon neutrality by 2045, details the policies and actions the state proposes to take to meet its ambitious climate goals. VMT reduction through increased use of public transit is an important part of this plan. 

While VMT was significantly reduced in 2020, during the COVID-19 pandemic, it has steadily increased to pre-pandemic levels. On average, public transit ridership is well below pre-pandemic levels in California, and transit’s fiscal crisis continues to exacerbate these impacts. To advance the goals of the Scoping Plan, this will require the state, regional/local agencies, and public transit operators closely examine how to improve public transportation services through securing the necessary funding to return transit operations to pre-pandemic levels, improvements to efficiency and reliability (including dedicated lanes and transit signal priority), zero emission vehicle technologies (including electric and hydrogen-fueled buses), innovative business models, and partnerships with the private sector. The Scoping Plan establishes targets for achieving per capita VMT reductions: 25 percent below 2019 levels by 2030 and 30 percent by 2045.  

To achieve these targets, it will require “state, regional, and local transportation, land use, and housing agencies, along with the Legislature and its budgeting choices” to collectively advance a wide range of VMT reduction strategies (2022 Scoping Plan, page 193). The Scoping Plan outlines a number of strategies including: 1) Shifting investments toward more public transit; 2) deploying seamless and integrated payment options for public transportation; 3) implementing equitable roadway pricing; 4) expanding active transportation infrastructure; 5) advancing innovative mobility options, including automated vehicle strategies and shared mobility options; and 7) ensuring alignment between housing and transportation policies that support infill and providing housing for lower-income communities.  

In my role as a CARB board member, it is very important to focus on VMT reductions through collaborations with many partners including other state agencies, the Legislature, regional/local government, public transit operators, and the private sector. Ensuring access for underserved communities and public transportation options for all travelers in urban, suburban, and rural areas aligns well with CARB’s social equity and air quality goals. 

Transit California:  You co-direct the Transportation Sustainability Research Center (TSRC) at UC Berkeley, a Center within the UC’s four-campus Institute of Transportation Studies (ITS). Among its many areas of focus, TSRC produces critical analysis about safe travel for transit-using populations with special needs or significant barriers to transit; transit systems’ emerging infrastructure, energy, and fuel needs under greenhouse gas emissions reduction targets; emerging shared mobility technologies; and more.  What are some current TRSC projects that transit industry professionals should be sure to watch for?  How can those in the transit industry most effectively access, use, and participate in the Center’s research? 

The Transportation Sustainability Research Center at the University of California, Berkeley, where I am a co-director and a professor in Civil and Environmental Engineering, is working on a number of projects that can advance safe, equitable, and environmentally sustainable public transportation options. For example, we are currently collaborating on numerous evaluations for the Federal Transit Administration’s Accelerating Innovative Mobility (AIM) and Integrated Mobility Innovation (IMI) programs. AIM includes 25 projects across 24 states, which were awarded a total of $14 million in August 2020. This includes a project with the Los Angeles County Metropolitan Transportation Authority (LA METRO) focused on innovative travel modes including public transit, ridesharing, and vanpooling. The IMI program concentrates on mobility on demand, transit automation, and payment integration. In March 2020, FTA awarded over $20 million to a portfolio of 25 IMI projects. One recipient is the San Joaquin Regional Transit District. This pilot is focused on payment integration and trip planning apps. We look forward to sharing our published research on these two programs and early understanding at conferences, such as the Transportation Research Board’s Annual Meeting. 

Recently, FTA released the Mobility on Demand Sandbox synthesis report on the program’s overall findings. Our research team co-authored this report and led the analysis. This volume synthesizes results across the 11 pilot projects, which were funded in 2016, which implemented public transit innovations with the private sector. It includes overall findings and lessons learned. Insights cover key takeaways on partnerships with the public sector, data sharing, scaling ridership, social equity, and environmental impacts. Alongside this synthesis, we also co-authored detailed evaluations on each of the 11 pilot projects. Third-party evaluation of pilot projects can provide important insights into what’s working, impacts, partnerships, and business model understanding to foster innovation in public transportation. 

TSRC is also conducting a number of projects on shared micromobility (e.g., scooters and bikes) as first- and last-mile strategies, social equity impacts, e-bike and scooter safety, and energy/environmental impacts. A local partnership that we enjoy with the Contra Costa Transportation Authority includes evaluations focused on mobility on demand strategies and a shared automated vehicle pilot. In addition, we are excited to lead a new multi-campus project focused on microtransit services deployed across California and Atlanta, Georgia with our colleagues at ITS Davis and ITS Irvine. This research will closely examine the role of microtransit services as a complement to fixed route public transit, along with its energy/environmental, social equity, and workforce impacts in a range of land-use environments.  

Our published research is available on our websites: tsrc.berkeley.edu and innovativemobility.org. We also provide a weekly newsletter, Last Week in Innovative Mobility, which features emerging technologies and services in public transportation and mobility overall. Transit California readers are welcome to subscribe at: tsrc.berkeley.edu (bottom of the homepage). 

Transit California: You are also the director of the UC ITS’ Resilient and Innovative Mobility Initiative (RIMI), which brings together transportation system decisionmakers and stakeholders at all levels to establish a long-term vision for a more sustainable and resilient transportation system in California. RIMI’s research is organized under three pillars – carbon neutral transportation, emerging transportation technology and innovation, and public transit and shared mobility. Are there particular research efforts at RIMI our members should follow?  How can those in the transit industry be a part of RIMI and/or benefit from RIMI research? 

The California Legislature funded the $10 million UC ITS Resilient and Innovative Mobility Initiative (RIMI) in 2021. Each of the three pillars you refer to have two cross-cutting themes: equity and workforce/jobs. The RIMI research portfolio was funded across two phases. While many research projects from Phase 1 have been completed, the majority are wrapping up in November 2023. The second research phase was funded in Summer 2023, with 12-to-18 month projects, including 11 public transit and shared mobility grants. We are excited to share the results from Phase 1 across the three pillar focus areas.  

As part of Phase 1, there are 14 Public Transit and Shared Mobility projects. They aim to: 1) provide insights into innovative finance and operational strategies; 2) understand what causes ridership declines and what policy levers can revive ridership, while improving services for underserved populations; 3) identify strategies to enhance public transit and shared mobility to ensure they are more adaptable to future pandemics, earthquakes, wildfires, and extreme weather events; 4) evaluate the role of public transit and shared mobility in achieving statewide VMT goals; and 5) understand the future of private shared mobility services and what role the public sector should play in supporting and regulating them. We have started communicating our findings at roundtable discussions, conferences, workshops, and webinars, as well as policy briefs and reports. Our research products are available on the UC ITS website. We will continue to share our research as it becomes available. We look forward to collaborating closely with public transit agencies and others throughout the state on our current and future research efforts funded through the SB1 program.  

Transit California: You have served as leadership in several transportation boards, including as vice-chair and then chair of the Transportation Research Board’s (TRB) Executive Committee, as well as serving as a member of numerous transportation and sustainability academic editorial boards.  How do these leadership positions inform your roles at CARB and at ITS? 

I have had the pleasure of contributing to the transportation field in a number of leadership roles, including serving on professional and editorial boards. My role on the Transportation Research Board (TRB) Executive Committee has provided me with numerous opportunities to learn and contribute. This includes leading through times of crisis and fostering resiliency, as I became the Vice Chair and Chair of the TRB Executive Committee during the first two years of the pandemic. We faced many challenges associated with the global pandemic—some financial, others logistical, and more. During this time, we provided critical advice to the U.S. Department of Transportation (DOT), the National Academies, the Legislature, etc. and developed a research pipeline to provide/share new insights with the transportation community about the pandemic and the so-called “new normal.” We also focused on addressing social and racial inequities through close collaborations across the industry and in partnership with the U.S. DOT.  

More recently, I have been immersed in developing and adopting a new strategic plan with key success metrics aimed at TRB’s internal organization and external impacts with the TRB Executive Committee and its Subcommittee on Planning and Policy Review, which I chair. We have also been developing a new Critical Issues consensus study report to inform our research priorities, creating a new framework for examining critical issues that integrate trends and metrics when possible, and identifying research gaps across all transportation modes. These documents help to set the stage for future research, initiatives, and tracking efforts of TRB and our vast volunteer network. Fostering collaboration among scholars, scientists, practitioners, and policymakers, as well as ensuring equity and outreach to individuals not yet at the table has been a key focus area for me.  

My work on editorial boards helps me to foster and stay on top of the latest research, methods, and data. I hope to continue to bring these insights and experiences to my work with UC ITS, TSRC, and CARB. Collaborating with people from a wide range of perspectives, hearing their voices, employing science and data to answer tough questions, and seeking common ground to solve complex challenges are all critical. I aim to bring my skills and experience in these areas to my new role at CARB. 

Transit California: Since 2022, you have served as co-chair of California Transportation Foundation Board’s (CTF) Scholarship Committee. Among other things, the CTF provides scholarships, education, mentorships, and internships to undergraduate and graduate students studying transportation-related fields.  What are some of the reasons your scholarship recipients cite as being interested in transportation, and can you speak to any barriers that prevent students from entering these fields of study?   

My contributions to the California Transportation Foundation (CTF) board have been deeply focused on giving back to the transportation community, awarding scholarships, and nurturing students in our field. Encouragement and contact with professionals is key to attracting the next generation of professionals to transportation. For instance, the CTF’s signature Education Symposium is a fantastic two-day event aimed at fostering connections between undergraduate students and professionals.  

At CTF, we distribute an incredible array of scholarships to California students at different levels—undergraduate, Masters, and Doctorate. We find that students really want to make a difference with their work, and many see transportation as core to quality of life and access to opportunities, including the need for a robust public transit network. While transportation provides many benefits, it also contributes to inequities, emissions, and other negative impacts. Students appreciate these connections and are interested in providing strategies to address them in their future work. Many love the technology/engineering aspects, others gravitate to planning and different facets of transportation, such as business and entrepreneurship. Our scholarships and educational programs can help to connect students with mentors, internships, and funding support. Many students face financial hardships, as living costs and tuition can be significant barriers. The CTF scholarships make a big difference in providing financial resources, and the foundation provides a forum for future success. We all need networks, mentors, and support to help us grow and develop in our careers. CTF is a noteworthy organization in fostering professional networks, starting with our students. 

Transit California: Some of your research has focused on improving transportation sustainability via reduced energy consumption, specifically by employing innovative mobility strategies that use technological advances or changes in people’s travel patterns and behaviors.  What are some of the most exciting emerging technologies that you are researching now to accomplish sustainability goals?  Are there policies that surprised you with their effectiveness (or ineffectiveness) in changing people’s transit patterns? 

I continue to be fascinated by shared mobility, which has been a research focus area of mine for close to 25 years. The services that continue to show energy/environmental benefits, along with positive equity impacts are carsharing and shared micromobility (active transportation via bikes and scooters). While these modes are not without their challenges, the analysis we conduct on impacts typically demonstrates net emission and VMT reductions—ranging across different business models and land-use environments. We are particularly interested in how such modes can help the state in meeting its VMT and emission reduction goals, along with providing greater access to underserved communities and public transit. Many of these services also introduce travelers to electric vehicles, as well as provide them mobility without the hassles and costs of private ownership. These modes often support a multi-modal lifestyle, including active transportation and public transportation use. One of the challenges is scaling these systems and maintaining sustainable business models across different environments. From a policy standpoint, parking policies have been largely successful in reducing the need for parking with carsharing vehicles, particularly in more urban areas with robust public transit networks. Policies that seem to have had more mixed results include providing passenger incentives for first- and last-mile trips to connect to public transit. For example, are the incentives being used for this purpose? As noted earlier, I am excited to partner with two UC campuses on better understanding microtransit services and how they might complement fixed route transit services and in which contexts.  

Transit California: Across your extensive career as a researcher, what role has the Association played? Are there additional opportunities for engagement? 

I have enjoyed a long history of engagement with the California Transit Association (Association). I have worked closely with Michael Pimentel and Josh Shaw in their respective roles as Executive Director with the Association at different times. Numerous times, I have had the pleasure of presenting/moderating at conferences and webinars led by the Association. I have also collaborated closely with Michael on two projects that I led recently, which focused on scenario planning in the context of public transit and telework impacts following the pandemic and targeted strategies in response to recovery efforts.  

In addition, the Association worked closely with our team at the UC ITS on the development of the RIMI program (noted earlier), which I now direct. We are deeply grateful for the Association’s tireless support since we launched the initiative. The Association has continued to provide us with invaluable feedback on our public transit and shared mobility projects, policy briefs, reports, webinars, and outreach activities. We look forward to future research opportunities to collaborate with the Association at UC ITS. As a CARB board member, I welcome opportunities to further explore the critical role that public transit plays in CARB’s VMT reduction strategies and the Innovative Clean Transit Regulation. 

Transit California:  What initially got you interested in researching sustainable transportation? 

I grew up in a small town in Upstate New York. My grandparents, parents, and brothers were closely tied to farming and agriculture, which fostered my appreciation for the environment. This attracted me to sustainability, caring for the planet, and my future career. After I finished my master’s degree, I moved to Washington, DC where I worked with the U.S. Environmental Protection Agency and Department of Energy for three years. My interests in energy and the environment flourished during this time. This motivated me to move to California to pursue my doctorate at UC Davis focusing on the energy and environmental aspects of transportation. Professor Daniel Sperling was my advisor and mentor at the Institute of Transportation Studies. The close connection among transportation, energy use, and environmental impacts, along with the allure of emerging technologies, led me to focus on sustainable transportation for my doctoral studies. I am deeply passionate about teaching, mentoring, and researching this topic. I am motivated to bring evidence-based research to policymaking to foster sustainable transportation strategies, address climate change, reduce criteria pollutant emissions, and elevate social equity in each of my roles. 

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