H.R. 6701 — HEAT Act of 2025

This section states congressional findings that extreme heat damages U.S. transportation infrastructure—including bridge expansion joints, concrete, steel, and movable bridges—with over 85,000 girder or movable bridges over 50 years old carrying 860 million vehicle crossings daily; that such damage disrupts supply chains and economies, especially in rural areas; and that extreme heat is not explicitly eligible for emergency relief funding under 23 U.S.C. 125.

This section expands eligibility under the emergency relief program for federal-aid highways (23 U.S.C. 125)—which authorizes up to $100 million annually from the Highway Trust Fund for repairing damage from natural disasters or catastrophic failures—by (1) adding extreme heat to the list of qualifying natural disasters in subsection (a)(1); (2) exempting from the subsection (b) bridge ineligibility restriction any bridge whose physical deterioration was substantially caused by extreme heat exposure; and (3) replacing each reference to "extreme weather, flooding, and other natural disasters" with "extreme weather, heat waves, flooding, and other natural disasters."

This section requires the Secretary of Transportation, no later than one year after enactment, to enter into an agreement with the Transportation Research Board (TRB) of the National Academies to conduct a study evaluating (1) the measurable costs of extreme heat events, particularly long-duration, high-intensity heat waves; (2) recommendations for tracking damage from such events separately from regular deterioration; and (3) ways the Secretary may better assist state departments of transportation, public transit systems, Amtrak, freight rail systems, and other parties in tracking that damage. In conducting the study, TRB must consult with the Secretary of Transportation, the EPA Administrator, state departments of transportation, public transit systems, Amtrak, freight rail systems, engineering and natural disaster management stakeholders, and educational or technical groups on extreme heat and infrastructure safety; TRB must submit a report on the study to the Secretary and the House Committee on Transportation and Infrastructure and the Senate Committee on Environment and Public Works.

This section directs the Secretary of Transportation to issue a best management practices report reflecting new information and advancements in highway and bridge safety related to extreme heat, not later than one year after the date of enactment of this Act.