State profile · Above median Poor share

Iowa bridge safety

According to the Federal Highway Administration's 2024 National Bridge Inventory, condition ratings, load ratings, and Poor-condition shares for every public highway bridge in Iowa.

23,719
Public bridges
38.8%
Good condition
19.2%
Poor condition

Iowa holds 23,719 public highway bridges (#7 of 52 by inventory) with a 19.16% Poor share (#1 of 52 by Poor share).

That is 19.2% of the state's inventory, against an average of 7.5% across the 54 states and territories with Poor-rated bridges on file, which places it 53 of 54 ordered from the lowest Poor share upward. A bridge is rated Poor when its weakest applicable component scores 4 or below on the inspecting agency's 0-9 scale, so the category is a maintenance and funding signal rather than a closure order or a live crossing-safety verdict.

Inventory: FHWA NBI 2024 · last ETL August 2026

Total Bridges

23,719

Public highway bridges in Iowa

Good Condition

38.8%

9,213 bridges rated 7-9

-11.2pp vs 50% benchmark

Poor Condition

19.2%

4,544 bridges whose lowest applicable component is rated 0-4

11.6pp vs national avg 7.5%

Iowa vs national bridge condition

Iowa - Good condition share 38.8%
National avg

Share of bridges rated 7-9 on the FHWA 0-9 scale (deck, superstructure, substructure all good).

Iowa - Poor-condition share 63.9%
National avg

Lower is better. Bar maxes at 30% (worst-state ceiling). National average sits at 7.5%.

Iowa in the national condition pattern

Each point is a state or territory in the FHWA NBI; the highlighted point is this profile.

Inventory size and Poor-condition share are different measures: Iowa has 23,719 bridges and a 19.2% Poor-condition share in the 2024 NBI, rank #53 of 54 jurisdictions ordered from the lowest share upward. The dashed comparisons mark the national average state rate and the midpoint of the plotted inventory range; neither is a live safety or closure threshold. Scatter plot of 54 data points. 0%10%20%30%40% 0k20k40k60k Public bridges in inventory (thousands) Poor-condition share (%) IA, Public bridges in inventory (thousands): 23.7k · Poor-condition share (%): 19.16%AL, Public bridges in inventory (thousands): 16.2k · Poor-condition share (%): 3.35%AK, Public bridges in inventory (thousands): 1.7k · Poor-condition share (%): 7.89%AZ, Public bridges in inventory (thousands): 8.6k · Poor-condition share (%): 1.15%AR, Public bridges in inventory (thousands): 13k · Poor-condition share (%): 5.43%CA, Public bridges in inventory (thousands): 25.8k · Poor-condition share (%): 5.91%CO, Public bridges in inventory (thousands): 9k · Poor-condition share (%): 4.82%CT, Public bridges in inventory (thousands): 4.4k · Poor-condition share (%): 4.72%DE, Public bridges in inventory (thousands): 0.9k · Poor-condition share (%): 1.26%DC, Public bridges in inventory (thousands): 0.3k · Poor-condition share (%): 1.95%FL, Public bridges in inventory (thousands): 13k · Poor-condition share (%): 2.79%GA, Public bridges in inventory (thousands): 15.1k · Poor-condition share (%): 1.59%GU, Public bridges in inventory (thousands): 0k · Poor-condition share (%): 12.77%HI, Public bridges in inventory (thousands): 1.2k · Poor-condition share (%): 6.53%ID, Public bridges in inventory (thousands): 4.6k · Poor-condition share (%): 4.9%IL, Public bridges in inventory (thousands): 26.9k · Poor-condition share (%): 9.35%IN, Public bridges in inventory (thousands): 19.5k · Poor-condition share (%): 5.22%KS, Public bridges in inventory (thousands): 24.9k · Poor-condition share (%): 5.26%KY, Public bridges in inventory (thousands): 14.5k · Poor-condition share (%): 7.37%LA, Public bridges in inventory (thousands): 12.7k · Poor-condition share (%): 11.48%ME, Public bridges in inventory (thousands): 2.5k · Poor-condition share (%): 15.41%MD, Public bridges in inventory (thousands): 5.5k · Poor-condition share (%): 4.56%MA, Public bridges in inventory (thousands): 5.3k · Poor-condition share (%): 8.88%MI, Public bridges in inventory (thousands): 11.4k · Poor-condition share (%): 11.27%MN, Public bridges in inventory (thousands): 13.5k · Poor-condition share (%): 4.44%MS, Public bridges in inventory (thousands): 16.7k · Poor-condition share (%): 6.03%MO, Public bridges in inventory (thousands): 24.6k · Poor-condition share (%): 8.95%MT, Public bridges in inventory (thousands): 5.2k · Poor-condition share (%): 6.81%NE, Public bridges in inventory (thousands): 15.4k · Poor-condition share (%): 7.9%NV, Public bridges in inventory (thousands): 2.1k · Poor-condition share (%): 1.14%NH, Public bridges in inventory (thousands): 2.5k · Poor-condition share (%): 7.51%NJ, Public bridges in inventory (thousands): 6.8k · Poor-condition share (%): 6.01%NM, Public bridges in inventory (thousands): 4k · Poor-condition share (%): 4.51%NY, Public bridges in inventory (thousands): 17.6k · Poor-condition share (%): 9.43%NC, Public bridges in inventory (thousands): 19.2k · Poor-condition share (%): 6.76%ND, Public bridges in inventory (thousands): 4.3k · Poor-condition share (%): 10.98%OH, Public bridges in inventory (thousands): 26.7k · Poor-condition share (%): 4.74%OK, Public bridges in inventory (thousands): 22.9k · Poor-condition share (%): 7.7%OR, Public bridges in inventory (thousands): 8.3k · Poor-condition share (%): 4.61%PA, Public bridges in inventory (thousands): 23.3k · Poor-condition share (%): 12.58%PR, Public bridges in inventory (thousands): 2.4k · Poor-condition share (%): 13.92%RI, Public bridges in inventory (thousands): 0.8k · Poor-condition share (%): 15.2%SC, Public bridges in inventory (thousands): 9.5k · Poor-condition share (%): 6.17%SD, Public bridges in inventory (thousands): 5.9k · Poor-condition share (%): 16.36%TN, Public bridges in inventory (thousands): 20.4k · Poor-condition share (%): 4.41%TX, Public bridges in inventory (thousands): 56.7k · Poor-condition share (%): 1.23%UT, Public bridges in inventory (thousands): 3.1k · Poor-condition share (%): 2.91%VT, Public bridges in inventory (thousands): 2.9k · Poor-condition share (%): 2.9%VI, Public bridges in inventory (thousands): 0k · Poor-condition share (%): 29.17%VA, Public bridges in inventory (thousands): 14.1k · Poor-condition share (%): 3.39%WA, Public bridges in inventory (thousands): 8.5k · Poor-condition share (%): 5.45%WV, Public bridges in inventory (thousands): 7.3k · Poor-condition share (%): 18.64%WI, Public bridges in inventory (thousands): 14.4k · Poor-condition share (%): 6.52%WY, Public bridges in inventory (thousands): 3.1k · Poor-condition share (%): 6.51%
Inventory size and Poor-condition share are different measures: Iowa has 23,719 bridges and a 19.2% Poor-condition share in the 2024 NBI, rank #53 of 54 jurisdictions ordered from the lowest share upward. The dashed comparisons mark the national average state rate and the midpoint of the plotted inventory range; neither is a live safety or closure threshold.

Iowa vs all states by public bridge inventory

Where this state's FHWA NBI public-highway bridge count sits among every state and territory on PlainBridges

23,719 7th of 54 higher than 47 of 54 states

States and territories, banded by public bridge inventory size

Each bar is a band; taller bars hold more states. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.

Source FHWA National Bridge Inventory · 2024

Read the rank neighborhood for Iowa

The highlighted point is Iowa: 23,719 bridges and 19.16% in Poor condition, rank #53 of 54 jurisdictions ordered from the lowest share upward. The five jurisdictions immediately above and below Iowa on that same Poor-share ordering:

  • South Dakota: 5,887 bridges · 16.36% Poor
  • West Virginia: 7,348 bridges · 18.64% Poor
  • Iowa: 23,719 bridges · 19.16% Poor
  • Virgin Islands: 24 bridges · 29.17% Poor

The full national sortable table lives on the rankings page.

Material families in Iowa

Exclusive FHWA material families across all 23,719 bridges in this state; continuous variants fold into the parent family. Orthogonal to the Poor-share scatter above.

Who maintains Iowa’s inventory

State agency holds 17.7% of the 23,719 public highway bridges filed under Iowa in the 2024 NBI, the agency-of-record split for this state, not a condition verdict.

When Iowa’s bridges were built

Pre-1950 construction accounts for 12.4% of the 23,719 bridges with a recorded original year in Iowa. Era bands are orthogonal to the Poor-share ranking above.

Condition Distribution

Iowa38.8%42%19.2%GoodFairPoor
Bridge inventory deck-condition mix - Iowa (FHWA NBI)

Counties (99)

Adair 306 Adams 186 Allamakee 197 Appanoose 183 Audubon 206 Benton 374 Black Hawk 489 Boone 135 Bremer 266 Buchanan 316 Buena Vista 156 Butler 289 Calhoun 197 Carroll 249 Cass 295 Cedar 301 Cerro Gordo 266 Cherokee 248 Chickasaw 302 Clarke 168 Clay 151 Clayton 256 Clinton 372 Crawford 301 Dallas 199 Davis 165 Decatur 197 Delaware 293 Des Moines 176 Dickinson 84 Dubuque 346 Emmet 78 Fayette 362 Floyd 213 Franklin 228 Fremont 179 Greene 168 Grundy 289 Guthrie 263 Hamilton 165 Hancock 138 Hardin 241 Harrison 217 Henry 173 Howard 210 Humboldt 87 Ida 182 Iowa 241 Jackson 246 Jasper 382 Jefferson 157 Johnson 372 Jones 231 Keokuk 183 Kossuth 267 Lee 214 Linn 506 Louisa 151 Lucas 195 Lyon 276 Madison 225 Mahaska 225 Marion 217 Marshall 304 Mills 184 Mitchell 167 Monona 162 Monroe 130 Montgomery 210 Muscatine 144 O'Brien 264 Osceola 185 Page 196 Palo Alto 135 Plymouth 432 Pocahontas 201 Polk 545 Pottawattamie 557 Poweshiek 248 Ringgold 217 Sac 224 Scott 291 Shelby 207 Sioux 449 Story 296 Tama 337 Taylor 220 Union 169 Van Buren 156 Wapello 190 Warren 239 Washington 207 Wayne 163 Webster 190 Winnebago 55 Winneshiek 342 Woodbury 455 Worth 116 Wright 182

Iowa vs nearby ranks

Adjacent states by Poor-condition share (lower share = better)

States are ranked by the share of bridges whose lowest applicable component rating is 4 or below. This describes recorded condition; it does not measure funding effectiveness or live crossing safety. States here sit immediately above and below Iowa on the same metric.

SD

South Dakota

16.36% top marginal rate
Structure
Progressive
Burden @ $100K
$5,887

WV

West Virginia

18.64% top marginal rate
Structure
Progressive
Burden @ $100K
$7,348
Selected

IA

Iowa

19.16% top marginal rate
Structure
Progressive
Burden @ $100K
$23,719

VI

Virgin Islands

29.17% top marginal rate
Structure
Progressive
Burden @ $100K
$24

Bridges Needing Most Attention in Iowa

Six lowest-condition bridges in Iowa, ranked by the portal's composite display score. Inspection intervals are risk-based under current NBIS rules.

MAIN ST

Poor

Over: IOWA RIVER

089211800, Hardin, IA

Built 1936 Load: 0.0 t ADT: 1,858

SO MAIN ST

Poor

Over: CASCADE LANDING

000000000, Des Moines, IA

Built 1896 Load: 0.0 t ADT: 743

E 13TH ST

Poor

Over: OVER I.C.E. RR

000000000, Scott, IA

Built 1900 Load: 0.0 t ADT: 358

EMERSON ST

Poor

Over: DRAINAGE

000000000, Madison, IA

Built 1965 Load: 0.0 t ADT: 396

1ST AVE S

Poor

Over: 21ST ST & RR

089282000, Webster, IA

Built 1968 Load: 0.0 t ADT: 9,860

1ST ST

Poor

Over: DRAINAGE

D60500515, Audubon, IA

Built 1930 Load: 0.0 t ADT: 9

All Bridges in Iowa

LOCAL

Fair

Over: PILOT CREEK

093321602, Pocahontas, IA

Built 1977 Load: 30.4 t ADT: 80

FM

Fair

Over: PILOT CREEK

093322502, Pocahontas, IA

Built 1975 Load: 30.4 t ADT: 20

LOCAL

Fair

Over: PILOT CREEK

093322602, Pocahontas, IA

Built 1977 Load: 30.4 t ADT: 30

LOCAL

Fair

Over: PILOT CREEK

093322701, Pocahontas, IA

Built 1977 Load: 30.4 t ADT: 30

FM

Fair

Over: N LIZARD CK DD #77

093332602, Pocahontas, IA

Built 1977 Load: 30.4 t ADT: 100

LOCAL

Fair

Over: N LIZARD CREEK

093332701, Pocahontas, IA

Built 1972 Load: 30.4 t ADT: 26

LOCAL

Fair

Over: N LIZARD CK DD #77

093333604, Pocahontas, IA

Built 1972 Load: 30.4 t ADT: 80

LOCAL

Fair

Over: DD #41 BIG CEDAR CK

093343401, Pocahontas, IA

Built 1977 Load: 30.4 t ADT: 330

FM

Fair

Over: FARM CREEK

074392801, Pottawattamie, IA

Built 1963 Load: 30.4 t ADT: 71

HONEYSUCKLE RD

Fair

Over: SLOCUM CREEK

075401103, Pottawattamie, IA

Built 1961 Load: 30.4 t ADT: 548

ORCHARD ROAD

Fair

Over: LITTLE MOSQUITO

075432804, Pottawattamie, IA

Built 1973 Load: 30.4 t ADT: 1,047

FM-MAHOGANY RD

Fair

Over: GREYBILL CREEK

076391301, Pottawattamie, IA

Built 1961 Load: 30.4 t ADT: 300

MAHOGANY ROAD

Fair

Over: BRANCH OF SILVER CREEK

076401603, Pottawattamie, IA

Built 1961 Load: 30.4 t ADT: 349

FM-WESTGATE RD

Fair

Over: PIGEON CREEK

077421703, Pottawattamie, IA

Built 1972 Load: 30.4 t ADT: 50

LOCAL

Fair

Over: STREAM

079152901, Poweshiek, IA

Built 2003 Load: 30.4 t ADT: 50

FM

Fair

Over: W FK GRAND RIVER

067310206, Ringgold, IA

Built 1979 Load: 30.4 t ADT: 270

300TH ST

Fair

Over: CREEK

080E41701, Scott, IA

Built 1970 Load: 30.4 t ADT: 1,390

FM

Fair

Over: E BR W NISHNABOTNA RIVER

079370602, Shelby, IA

Built 1972 Load: 30.4 t ADT: 588

B40

Fair

Over: FLOYD RIVER

095431001, Sioux, IA

Built 1977 Load: 30.4 t ADT: 1,795

FM

Fair

Over: DRY CREEK

096462102, Sioux, IA

Built 1967 Load: 30.4 t ADT: 1,077

LOCAL

Fair

Over: TWELVE MILE CREEK

086142906, Tama, IA

Built 2006 Load: 30.4 t ADT: 20

FM

Fair

Over: COTTON CREEK

074222704, Warren, IA

Built 1969 Load: 30.4 t ADT: 400

LOCAL ROAD

Fair

Over: DEER CREEK

077080403, Washington, IA

Built 1966 Load: 30.4 t ADT: 60

FM

Fair

Over: WOLF CREEK

0874414, Woodbury, IA

Built 1967 Load: 30.4 t ADT: 71

FM

Fair

Over: WOLF CREEK

0874415, Woodbury, IA

Built 1967 Load: 30.4 t ADT: 71

FM

Fair

Over: WRIGHT CREEK

088422102, Woodbury, IA

Built 1968 Load: 30.4 t ADT: 379

FM

Fair

Over: WOLF CREEK

088440503, Woodbury, IA

Built 1967 Load: 30.4 t ADT: 359

FM

Fair

Over: WHITE FOX CREEK

090253502, Wright, IA

Built 1967 Load: 30.4 t ADT: 26

ALBIA RD

Fair

Over: BEAR CREEK

072142704, Wapello, IA

Built 1967 Load: 30.4 t ADT: 810

C-02W

Fair

Over: VOLGA RIVER

009000510, Clayton, IA

Built 1975 Load: 30.4 t ADT: 690

US 218

Fair

Over: TRIB-SHELL ROCK RIVER

1.1 MI. N OF JCT. IA 3, Bremer, IA

Built 1996 Load: 30.4 t ADT: 8,300

SB I 35

Fair

Over: BAILEY CREEK

2.7 MI. N Jct. SR C13, Cerro Gordo, IA

Built 1971 Load: 30.4 t ADT: 8,650

ATTICA RD

Fair

Over: COMPETINE CREEK

075190712, Marion, IA

Built 1925 Load: 30.4 t ADT: 3,020

MAIN ST

Fair

Over: WAPSIPINICON RIVER

000000000, Linn, IA

Built 1952 Load: 30.5 t ADT: 3,187

3RD ST SW

Fair

Over: BEAR CREEK

3RD ST SW - BEAR CREEK, Dubuque, IA

Built 1966 Load: 30.5 t ADT: 2,333

NUCKOLS ST

Fair

Over: RED OAK CREEK

000000000, Montgomery, IA

Built 1971 Load: 30.5 t ADT: 479

IA 2

Fair

Over: W BRANCH LITTLE RIVER

1.2 MI. W OF W JCT. US 69, Decatur, IA

Built 1986 Load: 30.5 t ADT: 1,960

IA 21

Fair

Over: ENGLISH RIVER

2.3 mi. N of Jct. IA. 22, Keokuk, IA

Built 1984 Load: 30.5 t ADT: 1,490

SB I-35 WB I-80

Fair

Over: 6TH AVE

0.4 mi. W of Jct. IA 415, Polk, IA

Built 1958 Load: 30.5 t ADT: 43,750

HWY 20

Fair

Over: DRAINAGE DITCH

088301401, Webster, IA

Built 1984 Load: 30.5 t ADT: 1,482

FM

Fair

Over: UPPER IOWA RIVER

099060806, Allamakee, IA

Built 1974 Load: 30.5 t ADT: 69

FM

Fair

Over: SOUTH RIVER

073271204, Clarke, IA

Built 1968 Load: 30.5 t ADT: 29

FM 150 ST

Fair

Over: HONEY CREEK

090053501, Delaware, IA

Built 1949 Load: 30.5 t ADT: 363

BUTTERFIELD RD.

Fair

Over: FARM CREEK

086021106, Jones, IA

Built 1974 Load: 30.5 t ADT: 176

LINN-BENTON RD

Fair

Over: TRIB TO KNAPP CREEK

Benton-Linn Road, Linn, IA

Built 1972 Load: 30.5 t ADT: 1,530

FM

Fair

Over: BIG SLOUGH DRAINAGE DIT.

077040302, Muscatine, IA

Built 1968 Load: 30.5 t ADT: 150

ELMTREE ROAD

Fair

Over: GRAYBILL CREEK

075392901, Pottawattamie, IA

Built 1940 Load: 30.5 t ADT: 20

L14

Fair

Over: FLOYD RIVER

095433004, Sioux, IA

Built 1969 Load: 30.5 t ADT: 578

FM

Fair

Over: FLOYD RIVER

096430103, Sioux, IA

Built 1968 Load: 30.5 t ADT: 679

FM

Fair

Over: MIDDLE RIVER

075291006, Madison, IA

Built 1983 Load: 30.5 t ADT: 329

Showing 5,551-5,600 of 23,719 bridges

Related

All states → | National rankings → | Understanding conditions → | Retired SD term explained →
Data sourced from the FHWA National Bridge Inventory (NBI), latest released cycle. See our methodology for details. Retrieved and formatted by PlainBridges.

Disclaimer: This information is provided for informational purposes only and does not constitute professional advice. Data is sourced from the FHWA National Bridge Inventory (NBI). Poor condition is an inspection-record category, not a closure or unsafe-to-cross designation. Consult the bridge owner for current status.

Understanding Bridge Conditions

How FHWA rates bridge condition on a 0-9 scale.

Check Your Daily Bridges

How to look up bridge condition data for bridges on your route.

Read our methodology — how this data is sourced, computed, and verified.

What to do with this

Use Iowa's inventory picture to drill to a county or a specific span.

NBI condition ratings are inventory snapshots, not live crossing-safety verdicts.

Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. Iowa Good/Fair/Poor shares and county rollups on this page are computed from the same NBI extract as the national boards; no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2024 NBI release. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.