The law that authorized the largest federal investment in U.S. transportation infrastructure in decades is set to expire in fewer than five months. The Infrastructure Investment and Jobs Act (IIJA)—also known as the Bipartisan Infrastructure Law—reaches the end of its authorization period on September 30, 2026. Unless Congress passes a successor surface transportation bill before that date, the highway program's authorization will lapse, creating serious uncertainty for road, bridge, and transit projects across the country.

This is not a distant concern for the construction industry. The expiration is imminent, and the stakes are concrete.

What the IIJA Did—and What It Has Funded

Enacted in November 2021, the IIJA committed $1.2 trillion over five years, including approximately $550 billion in new infrastructure spending. For transportation specifically, it provided roughly $350 billion for highway programs over the five-year authorization window, according to the Federal Highway Administration. That represented a 67 percent funding increase over the prior surface transportation law.

The IIJA's impact on the ground has been measurable. States received formula funding for roads, bridges, and transit systems. Competitive grant programs like RAISE, INFRA, and the Bridge Investment Program directed billions to specific projects. The Bridge Investment Program alone made available $9.62 billion for fiscal years 2023 through 2026 for large and small bridge projects, per the Federal Highway Administration's Bridge Investment Program page. As of early 2026, an estimated $492 billion in IIJA funding had already been obligated or distributed, with remaining allocations running through the law's expiration, according to BuildingEX.

The Highway Trust Fund Problem

At the center of the reauthorization debate is a structural problem that predates the IIJA: the Highway Trust Fund is insolvent on a standalone basis. The fund is fed primarily by federal fuel taxes—18.4 cents per gallon for gasoline—rates that have not been raised since 1993. As vehicles have become more fuel-efficient and electric vehicles have grown in market share, fuel tax revenue has not kept pace with infrastructure costs.

The Congressional Budget Office projects the Highway Trust Fund will be depleted by 2028, with a cumulative shortfall reaching $280 billion by 2034, per Construction Dive. States face an additional $86.3 billion gap for roadway maintenance and repairs over the next decade. The next reauthorization bill must address this shortfall through some combination of alternative revenue, General Fund transfers, or new user fees—including a likely national registration fee for electric vehicles.

Where the Legislation Stands

The House Transportation and Infrastructure Committee, led by Chairman Sam Graves (R-Mo.) and Ranking Member Rick Larsen (D-Wash.), has been drafting a bipartisan reauthorization bill with the goal of committee markup as early as mid-May 2026, according to ENO Transportation Foundation. The Senate Environment and Public Works Committee has not yet released draft text. Both chambers must pass legislation and reconcile differences before September 30.

Early discussions have centered on a five-year bill in the $500 to $600 billion range, per AGC of America. The Associated General Contractors notes that while this sounds smaller than the IIJA's $1.2 trillion headline, the IIJA included significant one-time supplemental funding not present in a typical surface transportation authorization—so the comparison is not apples-to-apples. The practical core highway and transit programs may be funded at comparable or modestly higher levels than the IIJA's baseline.

The legislative calendar, however, is tight. With limited floor time between now and September 30 and ongoing negotiations on federal budget legislation, there is meaningful risk that Congress could allow the current law to lapse—or pass a short-term extension rather than a full multi-year bill.

Why a Lapse Would Hurt Construction

For general contractors and specialty subcontractors, the concern is straightforward: large, multi-year transportation projects require funding certainty before they can be designed, permitted, bid, and executed. A lapse in federal highway authorization does not necessarily halt projects in mid-construction—ongoing work typically continues—but it can freeze the pipeline of new project solicitations, slow state transportation department planning, and deter investment in equipment and workforce capacity.

The AGC of America has launched a $2 million "America's Moving Forward" campaign to pressure Congress to pass a new bill on time, warning that failure to act could stall multi-year highway, bridge, and transit megaprojects that are central to economic growth, according to the AGC's campaign page. The association's chief economist, Ken Simonson, has publicly stated: "Without a new multi-year authorization in place, states may struggle to launch the large, complex transportation projects that typically span several years and require funding certainty," per ConstructConnect News.

What Owners and Contractors Should Watch

Several near-term milestones will determine how this plays out:

• House T&I Committee markup (expected mid-May 2026): The first formal legislative text will reveal funding levels, program structure, and whether the Highway Trust Fund solvency question has been addressed.
• Senate EPW draft text: The Senate has not yet released bill language. How closely it aligns with the House will determine the difficulty of conference negotiations.
• Floor votes: With a narrowly divided House, building the 218-vote majority needed for passage—and the 60-vote Senate threshold—will require sustained bipartisan cooperation.
• September 30 deadline: If a full bill is not signed, watch for a continuing resolution or short-term extension that maintains current funding formulas while negotiations continue.

For owners and developers with long-horizon transportation-adjacent projects—logistics facilities, industrial parks, or developments reliant on highway access—the reauthorization outcome directly affects the infrastructure context of those investments. For contractors already active in highway and bridge work, maintaining strong relationships with state DOTs, monitoring bid calendars carefully, and being positioned to ramp quickly when a new law is signed will be key competitive advantages in the months ahead.

Sources:
- Federal Highway Administration: Infrastructure Investment and Jobs Act
- FHWA: Bridge Investment Program
- Construction Dive: Builders Face Uncertainty Without New Highway Bill
- ENO Transportation Foundation: Surface Reauthorization
- AGC of America: The Next Highway Bill — What the Numbers Really Mean
- AGC: America's Moving Forward Campaign
- ConstructConnect: AGC Launches America's Moving Forward
- BuildingEX: $492B in IIJA Funding Remains to Be Allocated
- T4America: How We Will Grade the Next Surface Reauthorization Bill