Introduction
In 2019, the National Academies of Sciences, Engineering, and Medicine hosted a workshop titled Enhancing Urban Sustainability with Data, Modeling, and Simulation.1 After the workshop, the planning committee discussed what questions and topics could be explored further. One of the most pressing issues the committee raised is that local decision makers struggle to respond to the myriad challenges in a community with a finite budget. Out of that conversation came the foundation for this workshop—Enhancing Urban Sustainability Infrastructure: Mathematical Approaches for Optimizing Investments.
Sponsored by the Environmental Protection Agency (EPA) and the National Academies’ George and Cynthia Mitchell Endowment for Sustainability Sciences, the National Academies’ Board on Mathematical Sciences and Analytics and Board on Infrastructure and the Constructed Environment convened this 3-day public workshop on July 13, 20, and 27, 2022, to explore state-of-the-art analytical tools that could advance urban sustainability2 through improved prioritization of public works projects. (See Box I-1 for the workshop’s statement of task.) Invited speakers included people working in urban sustainability, city planning, local public and private infrastructure, asset management, and infrastructure
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1 National Academies of Sciences, Engineering, and Medicine, 2019, Enhancing Urban Sustainability with Data, Modeling, and Simulation: Proceedings of a Workshop, Washington, DC: The National Academies Press, https://doi.org/10.17226/25480.
2 Ibid.
investment; city officials and utility officials; and statisticians, data scientists, mathematicians, economists, computer scientists, and artificial intelligence/machine learning experts. Day 1 provided an overview of the workshop, with an introduction of the practical constraints and funding challenges of decision making for local infrastructure, as well as the use of data and metrics to evaluate current infrastructure and make infrastructure investment decisions. This laid the groundwork for day 2, which focused on decision-making methods and considerations. During day 3, speakers discussed some specific topics of interest and concluded with a broader, more future-oriented discussion of sustainability. The
presentations and workshop discussions3 provided insights into new research areas that have the potential to advance urban sustainability in public works planning, as well as the barriers to their adoption.
I.1 OPENING REMARKS: CHALLENGES AND CONCERNS OF A MAYORAL OFFICE
Jeanne Holm, Deputy Mayor for Budget and Innovation of the City of Los Angeles, opened the workshop with an overview of the challenges and opportunities of decision making for sustainable urban infrastructure. Planning for and making decisions about urban infrastructure are complicated by their scale, expense, and long-lasting nature and by the multiple stakeholders and criteria that must be addressed.
Infrastructure is expensive, taxing the ability of cities to fund new projects and maintain existing systems. Los Angeles has an annual budget of almost $12 billion, but those funds must support city services and infrastructure that serve an area of 500 square miles containing 500,000 businesses and 4 million residents. Every city, no matter its size, is challenged by the funding requirements to build and maintain infrastructure.
Infrastructure’s long time horizon exceeds the length of election cycles, and city managers are often working with outdated or inaccurate data. Designing sustainable infrastructure requires consideration of technical expertise, project and budget planning, level of community disruption, and environmental impacts. Making decisions about infrastructure projects is, therefore, difficult both technically and politically. Decision making is further complicated by the multiple stakeholders affected by infrastructure projects and the environmental, economic, and social impacts that must be considered. The results of past decisions, which did not adequately consider these factors, have often exacerbated the very problems they had sought to solve.
Holm defined the “ideal city” as one that is sustainable, equitable, safe, and trusted; to achieve this vision, cities would benefit from increased data, funding streams, and community feedback. She pointed out that data access is critical both to understand short- and long-term impacts of actions and policies and to leverage predictive analytics for emerging issues and potential risks. Funding streams for this work could include taxes and bonds, municipal loans, one-time funds (e.g., American Rescue Plan), private-sector investment, philanthropic funds, and grant
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3 Videos of workshop presentations and discussions can be viewed at https://www.nationalacademies.org/our-work/enhancing-urban-sustainability-infrastructure-a-workshop-on-mathematical-approaches-for-optimizing-investments, accessed August 28, 2022.
and federal/state opportunities. She stressed that sustainable infrastructure is not just about creating green spaces and bike lanes; communities themselves should be sustainable, with ample opportunities for education, training, and employment. Feedback from these communities is essential and could be gathered via community involvement in projects, meetings, visualizations, and surveys.
Holm described the relationship between climate and sustainability as one of the most pressing issues for many city leaders and their communities. Climate change poses risks to virtually every infrastructure system and city service—water and sanitation, public health, biodiversity, residential areas, transportation, emergency services, food and agriculture, energy, commercial use, and land use. She highlighted Los Angeles’s fiscal year 2022–2023 climate investments, the goals for which are to mitigate climate change and to make fairer decisions. For example, the city’s Climate Equity Fund contains $10.5 million for air quality monitoring at oil drilling sites, climate vulnerability assessments, air purifier giveaways, and rebates for heat mitigation in homes. Other climate investments in Los Angeles support greenhouse gas tracking and construction of clean buildings, water resilience efforts, municipal vehicle electrification, and environmental justice. She added that Los Angeles received grants via Transformative Climate Communities (funded by California’s cap-and-trade program), which is a place-based strategy to reduce greenhouse gases and catalyze collective impact through community-driven projects in a single neighborhood.
Holm shared several examples of climate sustainability work in other cities across the world. She noted that the C40 Cities Climate Leadership Group,4 a global network of city mayors, recently launched an initiative for more than 1,000 cities to reach net-zero emissions by 2050. This partnership demonstrates that cities have impact well beyond the local level and can affect global climate. For example, Houston, a member of C40 Cities, is turning a landfill into an urban solar farm that generates electricity for 5,000 homes as part of its effort to become carbon neutral by 2050. An example of multicity efforts to improve environmental sustainability is the Electric Vehicle Purchasing Collaborative, for which more than 250 government entities have committed to purchasing at least 4,000 electric vehicles. In this case, Holm explained, cities help one another and make better choices without having to create anything new.
As an example of effective climate budgeting, Holm mentioned that Oslo, Norway, has embedded climate targets into the city’s standard
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4 For more information about the C40 Cities Climate Leadership Group, see https://www.c40.org, accessed August 28, 2022.
budgeting process: as the financial budget sets ceilings for annual spending, the climate budget sets ceilings on the volume of carbon dioxide that can be emitted in the city each year. And in Oregon, the Portland Clean Energy Community Benefit Fund, which was created by a local ballot measure in November 2018 that was supported by 65 percent of Portland voters, initiated a 1 percent surcharge on gross revenues from retail sales that is expected to generate $80 million–$90 million annually for renewable energy and energy efficiency programs; clean energy job training, apprenticeships, and contractor support; regenerative agriculture and green infrastructure programs; and future innovation.
In closing, Holm emphasized that although cities around the world are making progress, they would benefit from more data and better analysis to enhance sustainability. She encouraged city planners and community members to envision the ideal city and begin to design it together.
I.2 ORGANIZATION OF THIS WORKSHOP PROCEEDINGS
Chapter 1 presents the constraints and challenges of decision making for local infrastructure, such as selecting the right projects and making decisions under uncertainty. Chapter 2 describes the tools and data that communities need to make informed sustainability and infrastructure decisions, as well as the metrics and measures that capture the state of the various systems that support local infrastructure. Chapter 3 focuses on public investment theory and benefit-cost analysis for infrastructure and public works investment, with an emphasis on challenges and opportunities for local decision makers. Chapter 4 introduces state-of-the-art tools and practices for optimizing and improving the infrastructure investment process as well as the challenges that practitioners face in multi-objective decision making and when bridging the gap between theory and implementation. Chapter 5 highlights strategies to build confidence in data and the institutions that collect data amid community skepticism, privacy concerns, and challenges to evaluate data for inclusion and comprehensive representation. Chapter 6 summarizes research on social, physical, and digital infrastructure and showcases opportunities for improved community safety. Chapter 7 describes the risks of short-term thinking and practical tips for making long-term investments in and plans for a more sustainable future. Chapter 8 details varied perspectives of sustainability and examples of local communities that are working toward the goal of a sustainable city. Chapter 9 offers key themes from the workshop presentations and discussions, with a focus on the path forward. Many key resources for decision makers cited throughout the text are also compiled in Appendix A for quick reference.
This proceedings was prepared by the workshop rapporteur as a factual summary of what occurred at the workshop. The workshop planning committee’s role was limited to organizing and convening the workshop (see Appendix B for the workshop agenda and Appendix C for biographical sketches of the workshop planning committee members and speakers). The views expressed in this proceedings are those of the individual workshop participants and do not necessarily represent the views of the participants as a whole, the planning committee, or the National Academies.
