HEAT Act of 2025

(1) Extreme heat, particularly heat waves, are an emerging threat to critical transportation infrastructure.

(2) Extreme heat is damaging critical transportation infrastructure.

(3) Research indicates that high temperatures cause bridge expansion joints to crack or fail, accelerate the degradation of concrete and steel, and weaken structural integrity over time.

(4) Aging infrastructure is at heightened risk.

(5) Assessments show more than 85,000 girder or movable bridges are over 50 years old in the United States, carrying 860 million vehicle crossings each day.

(6) Many such bridges designed for historical conditions and are now experiencing stress beyond their original design.

(7) Movable bridges may face operational challenges, including breakdowns during heat waves.

(8) Steel expansion during extreme heat can cause drawbridges and similar structures to jam or fail to close properly.

(9) Emergency cooling measures, such as spraying bridges with water, have already been required in cities such as New York, Chicago, Portland, and Seattle.

(10) Extreme heat threatens economic continuity.

(11) Unplanned bridge closures and roadway restrictions caused by thermal stress interrupt freight movement, supply chains, and daily commuting, imposing significant costs on local economies and national productivity.

(12) Federal disaster programs omit extreme heat.

(13) While section 125 of title 23, United States Code, recognizes disasters such as flooding, severe storms, and wildfires, extreme heat is not explicitly identified as a qualifying event for Emergency Relief funding, despite its clear infrastructure consequences.

(14) Communities can face disproportionate risks.

(15) Rural areas and regions with limited redundancy in transportation networks are particularly at high risk, as heat-related transportation disruptions can isolate entire communities, delay emergency response, and endanger public safety.

(1) in subsection (a)(1), by inserting extreme heat, after severe storm,;

(2) in subsection (b) by inserting This subsection shall not apply to a bridge with respect to which physical deterioration was substantially caused by extreme heat exposure. after the period at the end; and

(3) by striking extreme weather, flooding, and other natural disasters each place it appears and inserting extreme weather, heat waves, flooding, and other natural disasters.

Not later than 1 year after the date of enactment of this Act, the Secretary of Transportation shall enter into an agreement with the Transportation Research Board of the National Academies, in coordination with the Secretary of Transportation, shall conduct a study to—

(1) evaluate the measurable costs of an extreme heat event, particularly long-duration, high intensity heat waves;

(2) provide recommendations on how to track damage from extreme heat events, separate from regular deterioration over time; and

(3) to examine how the Secretary may better assist State departments of transportation, public transit systems, Amtrak, freight rail systems, and other interested parties with tracking damage from extreme heat events.

In carrying out the study under this section, the Transportation Research Board shall consult with the Secretary, the Administrator of the Environmental Protection Agency, State departments of transportation, public transit systems, Amtrak, freight rail systems, stakeholders with expertise in engineering and natural disaster management, and educational and technical groups in extreme heat and infrastructure safety.

The Transportation Research Board shall submit to the Secretary, the Committee on Transportation and Infrastructure of the House of Representatives, and the Committee on Environment and Public Works of the Senate a report detailing the results of the study under this section.