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

US 30

Fair

Over: STREAM

5.5 mi. W of W jct. US 59, Crawford, IA

Built 1959 Load: 36.9 t ADT: 3,480

FM

Fair

Over: RACCOON RIVER OVERFLOW

078263005, Dallas, IA

Built 1973 Load: 36.9 t ADT: 1,942

IA 31

Fair

Over: STREAM

5.3 mi. N of jct. US 20, Ida, IA

Built 1974 Load: 36.9 t ADT: 1,600

IA 38

Fair

Over: MAQUOKETA RIVER

1.5 MI. N OF JCT. SR D62, Jones, IA

Built 1974 Load: 36.9 t ADT: 3,310

US 136

Fair

Over: MISSISSIPPI RIVER RR RD

OVER MISS. RIVER-KEOKUK, Lee, IA

Built 1985 Load: 36.9 t ADT: 10,500

US 18

Fair

Over: DRAINAGE DITCH

3.8 mi. W of IA 182, Lyon, IA

Built 1975 Load: 36.9 t ADT: 2,130

IA 3

Fair

Over: WESTFIELD CREEK

0.2 mi. W of W jct. IA 12, Plymouth, IA

Built 1962 Load: 36.9 t ADT: 1,570

IA 3

Fair

Over: BROKEN KETTLE CREEK

2.3 mi. W of SR K22, Plymouth, IA

Built 1975 Load: 36.9 t ADT: 940

US 6

Fair

Over: STREAM

2.0 MI. E. OF Jct. SR L66, Pottawattamie, IA

Built 1997 Load: 36.9 t ADT: 2,770

WB I-80

Fair

Over: SR V18

4.5 MI. W OF JCT. IA 21, Poweshiek, IA

Built 1963 Load: 36.9 t ADT: 13,350

IA 31

Fair

Over: STREAM

3.1 mi. S of SR D22, Woodbury, IA

Built 1956 Load: 36.9 t ADT: 1,070

FM

Fair

Over: BUCKEYE CREEK

082122405, Benton, IA

Built 1960 Load: 36.9 t ADT: 850

FM

Fair

Over: MUD CREEK

085102205, Benton, IA

Built 1992 Load: 36.9 t ADT: 1,532

FM

Fair

Over: BEAR CREEK

086100206, Benton, IA

Built 1991 Load: 36.9 t ADT: 658

FM

Fair

Over: BUCK CREEK

090102006, Buchanan, IA

Built 1972 Load: 36.9 t ADT: 1,277

FM

Fair

Over: CALEB CREEK

067241404, Decatur, IA

Built 1977 Load: 36.9 t ADT: 379

FM

Fair

Over: ROCK CREEK

097172402, Floyd, IA

Built 1996 Load: 36.9 t ADT: 1,365

FM

Fair

Over: CREEK

089152301, Grundy, IA

Built 1966 Load: 36.9 t ADT: 707

FM 2030 170TH

Fair

Over: DRAINAGE DITCH #9

095233201, Hancock, IA

Built 1975 Load: 36.9 t ADT: 688

1840 170TH ST

Fair

Over: E BR IOWA RIVER

095243601, Hancock, IA

Built 1975 Load: 36.9 t ADT: 649

FM

Fair

Over: ROCK CREEK

075121001, Keokuk, IA

Built 1979 Load: 36.9 t ADT: 50

FM

Fair

Over: S FORK CLANTON CREEK

074271506, Madison, IA

Built 1977 Load: 36.9 t ADT: 89

FM

Fair

Over: OTTER CREEK

099411901, Osceola, IA

Built 1975 Load: 36.9 t ADT: 199

450TH STREET

Fair

Over: FARM CREEK

074392202, Pottawattamie, IA

Built 1979 Load: 36.9 t ADT: 26

FM-JUNIPER ROAD

Fair

Over: WALNUT CREEK

076383401, Pottawattamie, IA

Built 1997 Load: 36.9 t ADT: 26

FROELICH RD

Fair

Over: STREAM

095043303, Clayton, IA

Built 1904 Load: 36.9 t ADT: 154

10TH ST

Fair

Over: BIG SIOUX RIVER

000000000, Sioux, IA

Built 1980 Load: 36.9 t ADT: 670

FM D-38

Fair

Over: I-380

2.8 mi. S of S Jct. US 20, Black Hawk, IA

Built 1984 Load: 36.9 t ADT: 854

IA 21

Fair

Over: STEIN CREEK

200 ft. N of Jct. SR E36, Benton, IA

Built 1979 Load: 37.0 t ADT: 1,470

IA 64 & 136

Fair

Over: LITTLE BEAR CREEK

0.2 mi. E of W Jct IA 136, Jones, IA

Built 1978 Load: 37.0 t ADT: 2,470

US 34

Fair

Over: DOUGLAS CREEK

0.7 MI. E of W JCT SR H34, Mills, IA

Built 1964 Load: 37.0 t ADT: 4,290

IA 22

Fair

Over: MOORE CREEK

3.4 mi. W of Jct. I-280, Scott, IA

Built 1972 Load: 37.0 t ADT: 3,830

I-280 WB

Fair

Over: EB I-80

AT JCT. I-280, Scott, IA

Built 1960 Load: 37.0 t ADT: 4,990

190TH ST

Fair

Over: STREAM

092142301, Bremer, IA

Built 1945 Load: 37.0 t ADT: 1,041

IA 140

Fair

Over: CLEAR CREEK

2.8 mi. S of IA 3, Plymouth, IA

Built 1964 Load: 37.0 t ADT: 1,130

FM

Fair

Over: MAPLE RIVER

086422708, Woodbury, IA

Built 1985 Load: 37.0 t ADT: 429

LOCAL

Fair

Over: JACKSON CREEK

068211104, Wayne, IA

Built 1993 Load: 37.0 t ADT: 11

28TH AVE

Fair

Over: INDIAN CREEK

000000000, Pottawattamie, IA

Built 1983 Load: 37.0 t ADT: 170

23RD AVE

Fair

Over: INDIAN CREEK

000000000, Pottawattamie, IA

Built 1980 Load: 37.0 t ADT: 7,347

HUDSON RD

Fair

Over: DRAINAGE DITCH

000000000, Black Hawk, IA

Built 1978 Load: 37.0 t ADT: 4,985

SB US 61 & 151

Fair

Over: IA 946 & CITY STS & RR

0.3 MI. S OF JCT. U.S. 20, Dubuque, IA

Built 1990 Load: 37.0 t ADT: 6,150

TRUMAN RD

Fair

Over: TURKEY CREEK

077340501, Cass, IA

Built 1987 Load: 37.1 t ADT: 170

US 71

Fair

Over: STREAM

1.1 MI. N OF Jct. SR F65, Audubon, IA

Built 1923 Load: 37.1 t ADT: 2,380

IA 44

Fair

Over: BLUEGRASS CREEK

0.1 MI. E OF JCT. US 71, Audubon, IA

Built 1959 Load: 37.1 t ADT: 830

LOCAL CONTY RD

Fair

Over: BUCK RUN CREEK

085332002, Carroll, IA

Built 1939 Load: 37.1 t ADT: 933

IA 4

Fair

Over: NORTH LIZARD CREEK

5.6 mi. N of IA 3, Pocahontas, IA

Built 1976 Load: 37.1 t ADT: 3,150

SB I-29

Fair

Over: OVER CC RR

2.1 MI. N OF JCT. 6, Pottawattamie, IA

Built 1968 Load: 37.1 t ADT: 5,800

FM G-30

Fair

Over: I-80

AT JCT SR G-30, Pottawattamie, IA

Built 1968 Load: 37.1 t ADT: 2,510

LOCAL

Fair

Over: BR PRAIRIE CK

082110802, Benton, IA

Built 1989 Load: 37.1 t ADT: 40

LOCAL

Fair

Over: BUCKEYE CREEK

082120901, Benton, IA

Built 1989 Load: 37.1 t ADT: 40

Showing 8,301-8,350 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.