City Forum

Extreme heat is a growing public health risk, yet its effects on pedestrian access to public transit remain poorly represented in conventional accessibility analysis. This study integrates microclimate simulation with pedestrian network analysis to examine how thermal stress alters station-area walkability and transit accessibility. Using LiDAR-derived urban morphology and the SOLWEIG model, we generate hourly Universal Thermal Climate Index fields for two contrasting Transit-Oriented Development corridors in Arlington, Virginia and Dallas, Texas. Thermal conditions are translated into time-varying pedestrian network impedance through network severance under extreme heat stress and inflation of walking time below this threshold. Accessibility is assessed using a cumulative opportunity framework weighted by transit service. Results show substantial reductions in realized accessibility during peak heat, with losses concentrated along specific pedestrian corridors, highlighting the importance of urban form and shading in supporting thermally resilient transit access. 

Do Yun's research interests lie at the intersection of climate-adaptive and inclusive transportation planning. Her work focuses on travel behaviors within this intersection, including walkability and transit access. She applies data-driven methods, geospatial analysis, machine learning algorithms, and urban climate modeling to examine the environmental and equity impacts of transportation systems and to support resilient mobility planning. 

Dr. Ming Zhang is a Professor and the Program Director of Community and Regional Planning in the School of Architecture at the University of Texas at Austin. Prior to joining UT Austin, Dr. Zhang held several academic and professional positions, including tenure-track Assistant Professor at Texas A&M University, Research Scientist at the Rockefeller Institute of Government in Albany, New York, and Lecturer and licensed Planner/Architect at the Huazhong (Central China) University of Science & Technology, Wuhan, China. 

City Forum is a planning and urban issues speaker series coordinated by the UT School of Architecture's Community and Regional Planning program. The series is intended to provide a space for open, critical dialogue regarding crucial planning-related issues in Austin and elsewhere, and to encourage discussion of diversity, multiple publics, and social change. All participants are welcome.