The Heat Emergency Assistance for Transportation (HEAT) Act of 2025 amends 23 U.S.C. §125 to recognize extreme heat and heat waves as qualifying events for Federal Highway Administration Emergency Relief (ER). It also inserts a narrow exception so that a statutory limitation in subsection (b) will not bar ER eligibility for bridges whose physical deterioration was substantially caused by extreme heat.
The bill replaces several statutory references to ‘‘extreme weather’’ with explicit mention of ‘‘heat waves,’’ signaling Congress’s intent to treat prolonged high-temperature events as discrete disaster drivers.
Beyond immediate eligibility changes, the bill directs the Department of Transportation to contract with the Transportation Research Board (National Academies) to study the measurable costs of severe heat events, develop approaches to separate heat-caused damage from ordinary wear, and recommend how the Secretary can assist state DOTs, transit systems, Amtrak, and freight rail. The Secretary must also publish a best management practices (BMP) report on highway and bridge safety related to extreme heat within one year.
Practically speaking, the bill broadens the statutory basis for ER claims tied to high temperatures while attempting to generate technical guidance for attribution and resilience—without specifying new funding streams or changing emergency relief payment formulas.
At a Glance
What It Does
The bill amends title 23, U.S. Code, §125 to add ‘‘extreme heat’’ and ‘‘heat waves’’ to the list of qualifying events for Emergency Relief. It adds an exception so that the limitation in subsection (b) does not disqualify bridges when deterioration was substantially caused by extreme heat, and it directs two studies/reports with one-year deadlines.
Who It Affects
State departments of transportation, local highway and bridge owners, public transit agencies, and freight operators that rely on highway and bridge networks will see immediate statutory implications for ER eligibility. The Transportation Research Board, the Federal Highway Administration (FHWA), and the Secretary of Transportation are tasked with studies and guidance development.
Why It Matters
This is a statutory recognition that heat can be a disaster driver for transportation infrastructure—potentially unlocking ER funding for heat-caused failures and pushing agencies to develop attribution methods and operational guidance. It changes the legal framing of natural-disaster eligibility and signals a shift toward climate-driven infrastructure policy even though it does not appropriate funds.
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What This Bill Actually Does
The HEAT Act modifies the Federal Highway Administration’s Emergency Relief authority in title 23 by explicitly naming extreme heat and heat waves as qualifying events. That matters because ER money typically flows after an event that is statutorily recognized as causing damage; by adding heat to the statute, the bill creates a clearer legal path to request ER assistance for heat-related bridge and roadway failures.
The statute change is targeted: it amends the language that lists disasters and adds a sentence to prevent an existing subsection (b) limitation from disqualifying bridges whose deterioration was substantially caused by heat.
To address the technical and evidentiary problems that follow from that eligibility expansion, the bill requires the Department of Transportation to contract with the Transportation Research Board to run a study. The study must quantify the direct costs of long-duration, high-intensity heat events to transportation assets; propose measurable indicators or methods that distinguish heat-caused damage from ordinary aging; and evaluate how the Secretary can help state DOTs, public transit agencies, Amtrak, and freight rail systems track and document such damage.
The bill prescribes a one-year window to initiate the contract and to produce the outputs that will inform agencies and Congress.Parallel to the TRB study, the Secretary must publish a best management practices report within one year that captures engineering and operational approaches to protect highways and bridges from extreme heat. The BMP is framed as guidance to reflect new information and technological advances; it does not, by itself, create new compliance obligations or alter funding formulas.
Taken together, the statutory eligibility change plus the study and BMP are intended to produce both immediate access to ER for heat events and longer-term technical standards and documentation practices to support program administration and resilience investments.
The Five Things You Need to Know
The bill inserts ‘‘extreme heat’’ and ‘‘heat waves’’ into 23 U.S.C. §125’s list of qualifying events for Federal Highway Administration Emergency Relief.
It adds a specific sentence to subsection (b) that exempts bridges from that subsection’s limitation when physical deterioration was substantially caused by extreme heat exposure.
The Secretary of Transportation must, within one year, contract with the Transportation Research Board (National Academies) to study measurable costs of extreme heat, attribution methods, and assistance for state DOTs, transit, Amtrak, and freight rail.
The Transportation Research Board is required to consult with EPA, state DOTs, public transit systems, Amtrak, freight rail, engineering and disaster-management stakeholders, and submit its report to the Secretary and relevant congressional committees.
The Secretary must issue a best management practices report on highway and bridge safety related to extreme heat within one year of enactment.
Section-by-Section Breakdown
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Short Title
Designates the statute’s working name as the ‘Heat Emergency Assistance for Transportation Act of 2025’ or ‘HEAT Act of 2025.’ This is purely nominative but signals congressional intent and frames subsequent provisions for rule writers and agency communications.
Findings
Lists the congressional findings that justify legislative action: bridges and other transportation assets face measurable risk from extreme heat, many bridges are old, heat can cause operational failures, and current federal disaster programs do not explicitly include extreme heat. These findings are not operative law but will be used to interpret the amendments and to justify prioritization in agency guidance and congressional oversight.
Emergency Relief: adding heat as a qualifying event and a bridge exception
This is the operative statute change. First, the bill inserts the terms ‘‘extreme heat’’ and ‘‘heat waves’’ into the clause that enumerates qualifying disasters for ER funding, making heat an explicit trigger for ER eligibility. Second, it appends a sentence to subsection (b) stating that subsection (b) will not apply to a bridge where physical deterioration was substantially caused by extreme heat exposure—an exception that, in practical terms, can allow ER funding for bridge repairs that might otherwise be excluded under whatever limitation subsection (b) imposes (for example, exclusions tied to routine deterioration or pre-existing conditions). Finally, it replaces several instances of the phrase ‘‘extreme weather, flooding, and other natural disasters’’ to add ‘‘heat waves,’’ standardizing the statutory language wherever that phrase appears.
TRB Study on Extreme Heat Events
Mandates that the DOT enter into an agreement with the Transportation Research Board within one year to conduct a focused study. The study's tasks include estimating measurable costs of prolonged, high-intensity heat events; developing methods to differentiate heat-caused damage from ordinary deterioration; and examining ways the Secretary can help state DOTs, transit agencies, Amtrak, and freight rail document and track heat damage. The provision prescribes consultations with EPA, state and local stakeholders, rail and transit operators, and technical experts and requires the TRB to send its report to the Secretary and the House and Senate committees named in the bill.
Best Management Practices Report
Requires the Secretary to issue a best management practices report within one year that reflects new information and technological advances in highway and bridge safety related to extreme heat. The report functions as nonbinding federal guidance to help owners and operators implement engineering, materials, and operational practices—such as cooling protocols, materials selection, inspection standards, or design adjustments—to reduce heat vulnerability.
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Explore Transportation in Codify Search →Who Benefits and Who Bears the Cost
Every bill creates winners and losers. Here's who stands to gain and who bears the cost.
Who Benefits
- State departments of transportation: Gain a clearer statutory basis to seek FHWA Emergency Relief funding for heat-related bridge and roadway damage, and will receive TRB guidance and a federal BMP to support technical claims and project designs.
- Local bridge and highway owners (municipalities and counties): Can use the amended ER language and the forthcoming BMP to justify emergency repairs and resilience investments after heat events that previously sat in a gray zone.
- Public transit agencies and certain freight interests: Benefit indirectly from the study’s mandate to examine how the Secretary can assist transit, Amtrak, and freight rail in tracking heat damage, which could yield operational and documentation tools to support future federal assistance.
- Engineering and resiliency consultants and contractors: Stand to win new work from increased claims, emergency repairs, retrofits, and implementation of BMP recommendations focused on materials and design changes for heat resilience.
Who Bears the Cost
- Federal government (FHWA/DOT): Faces potential increases in ER disbursements and administrative workload without an attached appropriation; DOT must also manage and oversee the TRB study and publish the BMP report within tight deadlines.
- State and local agencies: Must develop evidence and documentation protocols to show damage was ‘‘substantially caused’’ by extreme heat, increasing inspection, reporting, and engineering costs and potentially shifting maintenance priorities.
- Insurers and bridge owners: Could see increased claims and have to respond to changed definitions of qualifying events; insurers may push back or revise coverage terms, increasing premiums or disputes over attribution.
- Taxpayers/local budgets: If ER funds are insufficient or delayed, local governments may front repair costs; absent a new appropriation, expanding eligibility may compete with other ER claims and make local budgeting more uncertain.
Key Issues
The Core Tension
The central tension is between protecting communities and supply chains by broadening emergency relief to cover heat-driven infrastructure failures, and the fiscal and administrative risks that flow from making a diffuse, incremental hazard—heat—into a discrete, claimable disaster category: doing so helps bridge owners after acute events, but it requires difficult attribution rules, invites moral hazard, and may expand liabilities without new funding.
The bill enlarges ER eligibility without creating a dedicated funding stream or amending appropriations language. That matters because Title 23 ER payments typically come from existing FHWA funding mechanisms and FEMA coordination; expanding eligibility to heat-related deterioration could increase claims without an obvious source of new money, raising prioritization and fiscal exposure questions.
Implementation will require clear guidance on what constitutes ‘‘substantially caused’’ by extreme heat; the bill leans on the TRB study and a Secretary-issued BMP to supply methods, but those outputs are advisory and produce no automatic entitlement.
Attribution is the technical core problem. Heat often accelerates pre-existing degradation (e.g., thermal expansion exacerbating cracks), so splitting causation from wear-and-tear will demand new inspection regimes, baseline condition records, and potentially forensic engineering.
Those requirements impose administrative costs and create discretionary judgment calls that could generate disputes between state DOTs, FHWA, insurers, and Congress. The statute’s reach is limited to title 23 (highways and bridges); although the study must consult Amtrak and freight rail, the ER amendments do not directly alter statutory relief for rail or other modes, leaving a gap between the law’s intent and its practical coverage.
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