B. Xue, J. Zhang, B. Liu, M. Alberti, Y. Fan, D. Zhao, & N.B. Grimm, Accessibility–equality dynamics in urban blue and green spaces reshape human well-being, Proc. Natl. Acad. Sci. U.S.A. 123 (22) e2535714123, https://doi.org/10.1073/pnas.2535714123 (2026).
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Abstract
As urbanization accelerates, urban blue and green spaces are increasingly recognized as critical nature-based solutions for enhancing human well-being, delivering climate, environmental, and psychological benefits. Yet, the mechanisms by which access to these natural spaces and the equality of access by urbanites in diverse residential locations shape well-being remain poorly understood in the context of sustainable urban governance. Here, we systematically evaluated the spatiotemporal dynamics of urban blue and green space accessibility and equality across 279 Chinese cities from 2000–2100 and assessed their combined effects on well-being. We found that accessibility has a significant positive influence on well-being but follows an inverted-U-shaped pattern with distinct optimal thresholds. By contrast, equality shows a consistent, positive linear relationship with well-being. Although future accessibility is projected to improve, persistently high disparities among different segments of urban populations highlight the urgent need for equity-centered governance of blue and green spaces in cities. This perspective extends current approaches to environmental justice while revealing a structural mismatch between resource abundance and equitable distribution. To address this mismatch, we propose a prioritization framework that emphasizes context-specific, spatially targeted interventions, guided by four key drivers: the natural space to built-up area ratio, urban population size, the proportion of natural spaces with high accessibility, and urban landscape connectivity. By operationalizing these insights in an online toolkit for local governments, this work advances the fields of sustainable urban governance and equitable environmental planning.
Chalana, M., & Johnson, J. (21 May 2026). Emergence, Resilience, and Future(s) of Urban Informality in Seattle [White paper]. College of Built Environments. Emergence Resilience Futures Urban Informality Seattle-Chalana-Johnson-21May2026
Professor of Urban Design and Planning Marina Alberti has recently published a paper in Science, and been featured in a UW News story highlighting her work along with a large team of collaborative researchers. UDP PhD Student Anna Malesis-Dahm is another member of this research team who supported the the writing and conceptualization of the article published in Science. UW News featured Professor Alberti’s work in a Q&A piece, available here. The paper, “Evolving nature-based solutions for urban resilience” can…
Marina Alberti et al., Evolving nature-based solutions for urban resilience. Science 392, 701-708 (2026). DOI: 10.1126/science.aea9563.
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Abstract
Despite growing investments in nature-based solutions for urban resilience, their design often overlooks a fundamental biological process: evolution. Populations of organisms that sustain nature-based solutions are dynamic and can evolve over time. Rapid evolutionary changes, driven by urban environmental stressors, such as pollution, climate extremes, and habitat fragmentation, can reshape species’ traits, alter interactions, and shift ecosystem functions. We synthesize evidence of evolutionary change across systems that serve as nature-based solutions in urban contexts and show how evolutionary processes can enhance or undermine their performance. We propose four testable hypotheses linking evolutionary dynamics to nature-based solutions and outline design strategies to maintain adaptive potential. Integrating evolution into nature-based solutions is essential to ensure long-term and efficient functionality under accelerating environmental change.
The College of Built Environments hosted a two-day research showcase and PhD symposium honoring Anne Vernez Moudon’s legacy, bringing together students, faculty and industry leaders to reflect on her impact and highlight current research across urban design, mobility and public health.
The UW Solar interdisciplinary RSO visited the new solar canopy install in the E18 parking lot. This RSO is advised by Urban Design and Planning Associate Professor Jan Whittington. The successful solar canopy pilot will lead to future canopy install across other parking lots on campus. Read more at the full story here: https://facilities.uw.edu/blog/posts/2026/02/09/solar-canopy-uws-biggest-parking-lot-paves-way-brighter-future
Profs. H.W. Chris Lee, Rachel Berney, and Lingzi Wu hosted a successful stakeholder kick-off meeting for the WSDOT-funded Shore Power: Bremerton Transportation Center eMobility Project. The meeting drew strong participation from Washington State Ferries, Kitsap Transit, the City of Bremerton, Kitsap County, Puget Sound Energy, the Port of Bremerton, and the U.S. Navy. Agencies engaged in productive discussions on mobility challenges, electrification opportunities, and multimodal planning needs at the Bremerton Transportation Center. This collaborative launch sets a strong foundation for…
Chen, P., Shen, Q., & Boardman, S. (2025). Road User Fees in the USA: Theory, Research, and Practice. Journal of Planning Literature. https://doi.org/10.1177/08854122251385953
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Abstract
This paper examines the theory, research, and practice of road user charge (RUC) in the USA. It explores neoclassical, behavioral, and institutional economic perspectives to assess RUC's environmental benefits, data privacy, public acceptance, and equity implications. A synthesis of recent studies highlights RUC's financial, environmental, social, and urban transportation system impacts. The examination of state and regional initiatives presents several critical challenges associated with the implementation of RUC systems. This study provides a nuanced understanding of RUC's potential and barriers as a sustainable transportation funding mechanism and offers insights into future research and policy development.
Ashour, L., & Shen, Q. (2025). An outlook on ride-sourcing price changes: Implications for future transit agency-TNC partnerships. Transport Policy, 173, Article 103790. https://doi.org/10.1016/j.tranpol.2025.103790
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Abstract
Ride-sourcing trip prices charged by transportation network companies (TNCs) have increased significantly compared to before the pandemic, causing concerns about the effectiveness of existing and planned transit agency-TNC partnerships. This paper explores three scenarios of future TNC price changes: (1) price trend extension using forecasting models, (2) price increase in response to local policy changes, and (3) TNC/taxi price convergence due to increased competition. We then investigate the impact of TNC price change on the prospect of transit agency-TNC partnerships, using a case study in the Seattle region. For the first scenario, we employ two time-series models, namely ARIMA and PROPHET, to forecast price changes within the next three years (Oct 2022–Oct 2025) using publicly available Chicago TNC trip data. The results show that TNC's daily average price would reach $3.23 per mile, increasing by 40 % from 2019 average rates. For the second scenario, we track significant policies that directly impacted TNC prices in Seattle and incorporate reported price increases. The resulting estimations indicate that TNC prices would increase by an extra 25 % in response to changes in the minimum wage law. For the third scenario, we use publicly available taxi trip data of the city of Chicago and forecast future taxi prices by estimating time-series models comparable to those for TNC prices. The analysis suggests that due to increased competition, TNC and taxi prices are converging and that the average TNC fare per mile could add another 50 % to the forecasted price if TNC and taxi prices become similar in the upcoming three years. These price changes are shown to have a considerable negative impact on the expected cost-effectiveness of transit agency-TNC partnerships. Although such partnerships could still provide many benefits, transportation planners and policymakers should carefully examine the implications of TNC price increases resulting from changing market and policy environments.
Ashour, L., & Shen, Q. (2025). Incorporating equity into the cost-effectiveness evaluation of new mobility: A comparative analysis. Transportation Research. Part D, Transport and Environment, 147, Article 104959. https://doi.org/10.1016/j.trd.2025.104959
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Abstract
Public transportation in suburban areas faces challenges in providing efficient mobility. Transit Incorporating Mobility on Demand (TIMOD) services have emerged as a potential solution, yet equity considerations remain underexplored. This study incorporates equity into the cost-effectiveness evaluation of TIMOD services, analyzing two suburban areas in the Seattle metropolitan region where a TIMOD service is implemented. Using distributional cost-effectiveness analysis (DCEA), we assess the comparative costs of TIMOD, fixed-route transit, and drive-alone across different income groups and built environments. The study shows that although TIMOD services offer equity benefits for lower-income travelers, they are more equitable in high-density, low-income suburbs. In contrast, their cost-effectiveness is more limited in affluent, low-density areas. These insights highlight the importance of context-specific planning for TIMOD interventions and employ tools such as DCEA for transit agencies to prioritize the deployment of such services in areas where they can maximize social welfare and reduce transportation inequities.
