Protecting People in Midwest Road and Transport Systems During Periods of Extreme Heat

US transportation infrastructure requires significant increases in resilience to periods of extreme heat. Periods of extreme heat (as well as the related conditions of higher dew points and higher solar insolation) are increasing. This increase is clear in the observational record, and is one of the most certain climate impact predictions. Retrofits, operational adaptations, and changes to new construction are all needed to prevent economic disruption from road and rail transport problems related to extreme heat. This proposal moves beyond this first-order engineering problem of designing for extreme heat, and considers two critical second order problems: (a) the protection of people during extreme heat transportation emergencies; and (b) the compound effects of extreme heat and power outage. We will consider how operators, repair crews, the public, and public safety personnel can be kept safe on and around road and rail systems during extreme heat events. We will consider extreme heat events on their own and compounded with power outage. Our specific objectives include: create state and decade-specific (2020s, 2030s, 2040s, & 2050s) probabilities for extreme conditions, including geophysical variables (air temperature, winds, precipitation, soil moisture, solar insolation, and humidity); these will be coupled with existing models to derive human heat stress indices and infrastructure surface temperatures. Fault tree analyses will be conducted to assess critical factors that influence mortality of people during a “simple” extreme heat event, and during extreme heat combined with power outage.

"1A. Review of recent developments in methods and sources for future decade temperature estimates (and related variables such as RH, soil moisture, RH, etc.). We will seek estimates at 12 km or finer horizontal spatial resolution, under scenarios C1/SSP1-1.9, C3/SSP1-2.6,C6/SSP2-4.5, and C8/SSP5-8.5. Scenarios refer to the IPCC AR6 WGIII category and the WG1/II Shared Socio-economic Pathway. 1B. Stakeholder interviews. Officials responsible for heat response and mitigation will be interviewed about model and decision support tools. 1C. Gridded geophysical variable estimates by decade, state, and scenario for Iowa, Nebraska, Missouri, and Kansas (air temperature, winds, precipitation, humidity, soil moisture, solar insolation) 1D. Use of geophysical variables from previous task to predict transportation relevant temperature and heat indices (e.g., pavement temperatures, nearhighway ground temperatures, rail temperature, vehicle interior temperatures, operator heat stress indices) 1E. Assessment of predictions from previous step vs. measurements"

"The expected result is improved decision support tools to manage extreme heat events. Furthermore, we anticipate quantifying critical system vulnerabilities where infrastructure or planning upgrades will have the highest payback in terms of avoidance of human mortality in transport systems during periods of extreme heat."

"Broader impacts will come through use of our decision support tools and datasets. Dissemination will be through peer-reviewed and publicly available publications, public presentations (including MATC meetings and reports) and distribution of codes and data. Our target audiences include practicing engineers, academics, and government agencies. Our dissemination plan will be refined after stakeholder interviews (task 1B). Broader impacts will further come through incorporation of case studies and computer codes from this project in undergraduate and graduate education at the University of Iowa. The datasets are applicable to CBE:5104 Green Chemical and Energy Technology, CBE:5425 Atmospheric Chemistry and Physics, CBE:3020 Applied Statistics for Chemical and Natural Resource Engineering and to many courses in the Civil and Environmental Engineering Department. Broader impact will further come through mentoring and training of students and staff on this project. "