Bridge Conditions Across America

What "Structurally Deficient" Actually Means

The phrase "structurally deficient" sounds alarming. It conjures images of bridges on the verge of collapse. The reality is more nuanced, and understanding the distinction matters if you're going to make sense of the data that follows.

Every bridge in the United States is inspected at least once every two years under the National Bridge Inspection Program. Inspectors rate the condition of three primary components (the deck, the superstructure, and the substructure) on a scale from 0 (failed) to 9 (excellent). If any one of those components receives a rating of 4 or below, the bridge is classified as being in "poor condition." (FHWA NBI, 2025)

Prior to 2018, the Federal Highway Administration used the term "structurally deficient" for these bridges. That language was retired in favor of "poor condition" because it was widely misunderstood. A bridge rated in poor condition is not necessarily unsafe. It is a bridge that transportation officials have identified as needing significant maintenance, rehabilitation, or replacement. These bridges are still open to traffic, still inspected regularly, and still managed within load-posting limits when necessary. But they represent structures where the clock is ticking on deferred maintenance.

The National Picture

The United States has 623,000 bridges carrying traffic across waterways, rail lines, and roadways. According to the most recent National Bridge Inventory data, released in June 2025, the condition breakdown looks like this:

That 6.7% figure represents slow but real progress. A decade ago, nearly 9% of the nation's bridges were in poor condition. The trend is moving in the right direction, driven by sustained federal and state investment. But the pace of improvement has slowed in recent years, and two other numbers tell a less optimistic story. First, 220,300 bridges (roughly 35% of the entire inventory) need some form of major repair or replacement. (ARTBA, 2025) Second, the average American bridge is now 47 years old, approaching the 50-year design lifespan that most were built to. (ASCE, 2025)

Meanwhile, the ASCE gave the nation's bridges a grade of C in its 2025 Infrastructure Report Card, unchanged from 2021. That flat grade signals that despite progress on the worst bridges, the broader inventory is aging faster than it's being renewed. (ASCE, 2025)

State-by-State Rankings

Bridge conditions vary dramatically by state. Iowa has more than 4,400 bridges in poor condition, the highest raw count in the nation, and nearly one in five of its bridges carries that classification. At the other end of the spectrum, Nevada has fewer than 30 bridges in poor condition, representing barely 1% of its inventory.

The table below ranks the 15 states with the highest percentage of bridges in poor condition, based on the ARTBA 2025 Bridge Report.

Rank	State	Total Bridges	Poor Condition	% Poor	Since 2021
1	Iowa	23,716	4,424	19%	Flat (19% → 19%)
2	West Virginia	7,345	1,307	18%	Improving (20% → 18%, −183 bridges)
3	South Dakota	5,883	945	16%	Improving (17% → 16%, −73 bridges)
4	Maine	2,542	392	15%	Worsening (13% → 15%, +78 bridges)
5	Rhode Island	787	110	14%	Improving (18% → 14%, −26 bridges)
6	Pennsylvania	23,314	2,813	12%	Improving (14% → 12%, −385 bridges)
7	Louisiana	12,684	1,423	11%	Improving (13% → 11%, −208 bridges)
8	North Dakota	4,250	470	11%	Flat (11% → 11%)
9	Michigan	11,397	1,250	11%	Flat (11% → 11%)
10	New York	17,666	1,741	10%	Flat (10% → 10%)
11	Illinois	26,927	2,563	10%	Worsening (9% → 10%, +158 bridges)
12	Massachusetts	5,311	501	9%	Flat (9% → 9%)
13	Missouri	24,647	2,163	9%	Flat (9% → 9%)
14	New Hampshire	2,549	192	8%	Flat (8% → 8%)
15	Oklahoma	22,926	1,719	8%	Improving (10% → 8%, −577 bridges)

The national average is 6.7%. Every state in this table is well above it. But the numbers alone don't tell the full story. A state with 110 bridges in poor condition (Rhode Island) faces a fundamentally different challenge than one with 4,424 (Iowa), even if their percentages are comparable. Scale, geography, and ownership patterns all shape the problem and the path to solving it.

It's worth noting the scale of the problem varies enormously even among the worst states. Oklahoma and Missouri both sit at 8–9%, but they each have over 20,000 bridges — meaning their raw counts of poor bridges (1,719 and 2,163 respectively) rival or exceed states ranked much higher by percentage. Meanwhile, New Hampshire has only 192 poor bridges but makes the top 15 because its inventory is small. The percentage tells you how bad the problem is relative to a state's infrastructure; the raw count tells you how big the repair job actually is.

The Rural and County Bridge Crisis

The national statistics obscure a critical asymmetry: the bridge problem is overwhelmingly concentrated in rural America. About 80% of all bridges in poor condition are located in rural areas. (BTS, 2024) The ownership structure tells you why. The vast majority of rural bridges are owned not by state departments of transportation but by county and local governments operating on constrained budgets with limited engineering capacity.

The data on ownership is striking. In 2024, 8.9% of locally owned bridges were rated in poor condition, compared to just 4.4% of state-owned bridges. (FHWA NBI, 2024) That gap is not a coincidence. State DOTs have dedicated bridge programs, professional inspection staff, and access to federal formula funds. County highway departments are often staffed by a handful of people responsible for hundreds of structures, competing with road maintenance, snow removal, and every other demand on a local budget.

The gap between interstate and local road bridges is even more pronounced. In rural areas, just 3% of Interstate Highway bridges were in poor condition in 2019. On rural local roads, the farm-to-market routes and county roads connecting small towns, that number was 11%. (BTS) These are the bridges that school buses cross, that fire trucks depend on, that farmers use to move equipment between fields. When one of them gets weight-posted or closed, the consequences are immediate and tangible.

What This Looks Like on the Ground

The numbers in the sections above describe the scope of the problem. The consequences show up in specific communities, on specific roads, and in the daily routines of people who depend on these bridges without thinking about them.

When bridges get weight-posted

When a bridge is weight-posted (restricted to vehicles below a certain tonnage), the effects cascade outward through a community. According to the TRIP Rural Connections Report, bridges rated in poor condition are often posted for lower weight limits or closed to traffic entirely, restricting or redirecting large vehicles including agricultural equipment, commercial trucks, school buses, and emergency services vehicles. (TRIP, 2024)

For a farmer whose combine exceeds the posted limit, a weight-restricted bridge can turn a five-minute trip between fields into a multi-mile detour on gravel roads that weren't designed for heavy equipment. School buses reroute, adding time and miles to morning runs. Businesses that depend on truck deliveries absorb higher costs or lose service altogether. The economic toll is diffuse but real: fuel costs rise, travel times increase, and pavement on the detour routes deteriorates faster under the redirected traffic load.

When bridges fail

The most visible consequences come when a bridge fails outright. On January 28, 2022, the Fern Hollow Bridge in Pittsburgh, Pennsylvania collapsed roughly 100 feet into Frick Park, injuring four people and severing a 16-inch natural gas pipeline that forced the evacuation of nearby residents. The 447-foot bridge had been inspected repeatedly over the years, and maintenance and repair recommendations had been documented but not acted on. The NTSB investigation concluded that clogged drains allowed water to corrode critical structural components, and that the collapse was the direct result of maintenance and oversight failures. (NTSB, 2024)

Two years later, in March 2024, the Francis Scott Key Bridge in Baltimore collapsed after a container ship strike, killing six workers and closing the Port of Baltimore. The economic disruption was staggering: the port generates roughly $70 billion in annual economic impact and supports 43,000 jobs. More than 12 million vehicles crossed that bridge annually. While the Key Bridge collapse had a different cause than the slow deterioration affecting most poor-condition bridges, it demonstrated how a single bridge failure can ripple through an entire regional economy. (Richmond Fed, 2024)

Emergency response and access

In western Independence, Missouri, a cluster of bridge closures has directly affected emergency response coverage. Fire and ambulance crews that previously used those bridges as primary routes now face longer paths to calls, adding minutes to response times in cardiac events and structure fires where those minutes matter. (KSHB, 2024) This pattern is common across rural America. Rural residents already wait nearly twice as long for ambulances as urban residents do, according to the Health Resources and Services Administration. (HRSA) When a bridge closure or weight restriction eliminates the most direct route to a hospital or fire station, it compounds an existing disadvantage.

The equity dimension

The communities most affected by bridge deterioration are disproportionately rural, lower-income, and less politically visible. They lack the tax base to self-fund replacements and the lobbying infrastructure to compete for discretionary grants. Research in Massachusetts has found that proximity to structurally deficient bridges correlates with minority communities, adding a civil-rights dimension to what is often framed as a purely technical problem. (ASCE, 2025)

This is the core tension: the places with the worst bridges are the places least equipped to fix them.

What replacement looks like

Missouri's FARM Bridge Program offers a model of what targeted investment can accomplish. Using a $20.8 million federal grant supplemented by $5.2 million from MoDOT, the program replaced 31 one-lane, timber-pile bridges across northern Missouri's rural counties. The bridges being replaced were weight-restricted, two-way traffic structures averaging 80 years old, with the oldest dating to 1930. The design-build approach completed all 31 replacements ahead of schedule, restoring full access for agricultural equipment and emergency vehicles to communities in Worth, Gentry, and surrounding counties. (MoDOT; Bridge Design & Engineering)

Programs like FARM demonstrate that the problem is solvable when funding reaches the right level of government. The challenge is scale: 31 bridges is meaningful for northern Missouri, but there are thousands of similar structures across the country waiting for the same treatment.

Where the Money Is Going

The Infrastructure Investment and Jobs Act, signed into law in November 2021, created the largest dedicated bridge investment since the construction of the Interstate Highway System. The Bridge Formula Program provides $27.5 billion to states over five years (FY 2022 through 2026), distributed through a formula that weights 75% toward the cost of replacing poor-condition bridges and 25% toward rehabilitating fair-condition bridges. (FHWA)

Alongside the formula program, the competitive Bridge Investment Program adds another $12.5 billion for large-scale projects that wouldn't be feasible through formula funds alone. Together, these programs represent roughly $40 billion in dedicated bridge funding. That is a historic figure, though still well short of the $467 billion ARTBA estimates would be needed to address all identified repair needs. (ARTBA, 2025)

As of mid-2025, states have committed 62% of the Bridge Formula Program funds released through the first four years, approximately $13.2 billion supporting over 6,000 projects. (ARTBA, 2025) That leaves 38% of already-released funds uncommitted, plus the final year's $5.3 billion allocation still to come before the law's September 2026 expiration. The deployment pace is uneven: some states moved quickly to put funds to work, while others have been slower to identify and advance projects through their planning and environmental review processes.

The Bridge Formula Program requires each state to set aside 15% of its allocation specifically for off-system bridges, structures not on the federal-aid highway network that are disproportionately rural and locally owned. For these off-system bridges, the federal government covers 100% of the cost, eliminating the usual 20% local match requirement. Every state receives a minimum of $45 million per year from the program, regardless of its bridge inventory size. The formula-driven allocations above that floor reflect each state's relative share of bridges in poor and fair condition. States with the largest bridge repair backlogs (Pennsylvania, Iowa, Illinois, New York) receive proportionally larger shares.

Bridge Conditions by State

Looking Ahead

The trajectory is cautiously encouraging. The national percentage of bridges in poor condition has declined from roughly 9% to 6.7% over the past decade, and the IIJA's dedicated bridge programs have accelerated investment in ways that weren't possible under previous authorization levels. Thousands of bridges are being repaired or replaced right now, and the off-system bridge provisions are directing money toward the rural and county-owned structures that need it most.

But there are real reasons for concern. Several states are moving in the wrong direction, adding bridges to the poor-condition list faster than they're repairing them. The 38% of Bridge Formula Program funds that remain uncommitted represents capacity that hasn't been deployed with just one year remaining in the current authorization. And the IIJA itself expires on September 30, 2026. The bridge programs it created are not permanent. If the next surface transportation authorization reduces dedicated bridge funding or changes the formula structure, the progress made over the past five years could stall.

The bridge inventory does not stop aging while Congress deliberates. The average bridge is 47 years old. More than 12% of all highway bridges are over 80. Over 22,000 bridges in the national inventory are flagged as susceptible to storms and extreme weather events. (ASCE, 2025) The bridges least able to absorb additional stress are the same ones that have been deteriorating from deferred maintenance for decades.

The question ahead is not whether the problem is solvable. Programs like Missouri's FARM Bridge initiative demonstrate that it is, when funding reaches the communities that need it. The question is whether the political commitment to sustained bridge investment will outlast the current authorization cycle, or whether the nation returns to the pattern of underfunding that created the backlog in the first place.

This page will be updated annually following the release of new NBI data, typically in the summer. If the data changes, so will the story. We'll be watching.

State Deep Dives

These pages take a closer look at bridge conditions in individual states, listed by national rank. Each covers ownership breakdowns, county-level data, funding sources, and the specific factors driving deterioration.

1. Iowa — 4,424 bridges in poor condition (19%), driven by the largest county-owned bridge inventory in the country.
2. West Virginia — 1,307 bridges in poor condition (18%), concentrated in state-owned structures through steep Appalachian terrain.
3. South Dakota — 945 bridges in poor condition (16%), split by the Missouri River into two regions with distinct bridge challenges.
4. Maine — 392 bridges in poor condition (15%), with no county government layer and a gas tax frozen since 2011 squeezing the state's repair capacity.
5. Rhode Island — 110 bridges in poor condition (14%), down from the worst ranking in America a decade ago, with the $571 million Washington Bridge replacement now under construction.
6. Pennsylvania — 2,813 bridges in poor condition (12%), down from the worst ranking in America in 2013 after Act 89 generated $2.3 billion annually, but the Fern Hollow Bridge collapse showed the gap between progress and outcome.
7. Louisiana — 1,423 bridges in poor condition (11%), compounded by seven major hurricanes in 16 years, coastal subsidence, and the densest waterway crossings per road-mile in the country.
8. North Dakota — 470 bridges in poor condition (11%), where the Bakken oil boom broke county bridges faster than oil revenue could fix them and the rate has been flat at 11% for years despite billions in infrastructure spending.
9. Michigan — 1,250 bridges in poor condition (11%), where industrial-scale road salt accelerates deterioration and a $3.5 billion bonding program that held the rate steady is running out of money.
10. New York — 1,741 bridges in poor condition (10%), where the average bridge is 50 years old, the worst rates are upstate, and NYC accounts for $19.1 billion of the $29 billion local bridge backlog.
11. Illinois — 2,563 bridges in poor condition (10%), where the third-largest inventory in the country is fragmented across roughly 7,000 units of local government and 1,428 townships, and the poor-bridge count rose even as billions in state and federal funding deployed.
12. Massachusetts — 501 bridges in poor condition (9%), where a $3 billion Accelerated Bridge Program cut the count from 543 to 432, then the gains eroded after the program ended and the state is now mounting another major investment push.
13. Missouri — 2,163 bridges in poor condition (9%), where three successive capital programs replaced or improved over 1,080 bridges and dropped the count from roughly 3,085, but base funding was frozen for 25 years and the first gas tax increase in decades already faces repeal pressure.
14. New Hampshire — 192 bridges in poor condition (8%), where the only state in the top 15 with no income tax and no sales tax runs a Red List monitoring program most states lack, but the gas tax increase that funds repairs is temporary and the municipal bridge aid program is full.
15. Oklahoma — 1,719 bridges in poor condition (8%), where the state highway system went from 49th to 4th nationally in two decades but county bridges hold 87% of all poor bridges and the CIRB program replaces them at a fraction of the pace.