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

MORNINGSIDE AVE

Fair

Over: US 20

At Jct. SR D25, Woodbury, IA

Built 1978 Load: 34.6 t ADT: 6,217

SB US 218

Fair

Over: F50 (OAK CREST HILL RD)

1.6 mi. S of Jct. IA 1, Johnson, IA

Built 1983 Load: 34.6 t ADT: 8,550

IA 150

Fair

Over: BRANCH BEAR CREEK

0.1 MI. N OF JCT. SR D48, Buchanan, IA

Built 1983 Load: 34.7 t ADT: 4,530

IA 14

Fair

Over: W FK CEDAR RIVER

0.3 mi. N of jct. SR C51, Butler, IA

Built 1984 Load: 34.7 t ADT: 1,160

US 30

Fair

Over: HARDIN CREEK

1.8 MI. E OF JCT. IA 4, Greene, IA

Built 1957 Load: 34.7 t ADT: 4,230

FM

Fair

Over: SMALL STREAM

080203403, Jasper, IA

Built 1951 Load: 34.7 t ADT: 2,260

IA 3

Fair

Over: BIG SIOUX OVERFLOW

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

Built 1962 Load: 34.7 t ADT: 1,570

I 29 SB

Fair

Over: I 880

At N Jct. I-880, Pottawattamie, IA

Built 1966 Load: 34.7 t ADT: 9,750

EB US 30

Fair

Over: OVER UP RR

0.1 MILE W OF JCT SR S14, Story, IA

Built 1963 Load: 34.7 t ADT: 7,900

IA 92

Fair

Over: SOUTH RIVER

0.4 MI E OF E JCT SR S23, Warren, IA

Built 1983 Load: 34.7 t ADT: 2,190

CO RD 105

Fair

Over: ELK CREEK

099220303, Worth, IA

Built 1926 Load: 34.7 t ADT: 1,139

LOCAL

Fair

Over: STREAM

075331304, Adair, IA

Built 1991 Load: 34.7 t ADT: 41

LOCAL

Fair

Over: NINE MILE CREEK

076331401, Adair, IA

Built 1955 Load: 34.7 t ADT: 41

LOCAL

Fair

Over: STREAM

083121101, Benton, IA

Built 1958 Load: 34.7 t ADT: 20

W REINBECK RD

Fair

Over: TRIB TO MILLER CREEK

87-13-28-01-10, Black Hawk, IA

Built 2001 Load: 34.7 t ADT: 11

300TH AVE

Fair

Over: STREAM

097353302, Clay, IA

Built 2000 Load: 34.7 t ADT: 11

FM

Fair

Over: SO RACCOON RIVER

078281610, Dallas, IA

Built 1993 Load: 34.7 t ADT: 1,474

COUNTY RD E-45

Fair

Over: SMALL CREEK

083010707, Jones, IA

Built 1980 Load: 34.7 t ADT: 422

120TH AVE

Fair

Over: SMALL CREEK

083022902, Jones, IA

Built 1980 Load: 34.7 t ADT: 16

60TH AVE.

Fair

Over: SMALL CREEK

084011904, Jones, IA

Built 2007 Load: 34.7 t ADT: 123

BOYSCOUTS RD

Fair

Over: WAPSIPINICON RIVER

085052003, Linn, IA

Built 1976 Load: 34.7 t ADT: 226

FM

Fair

Over: SKUNK RIVER

077180304, Marion, IA

Built 1948 Load: 34.7 t ADT: 1,300

FM

Fair

Over: DRY RUN

076040303, Muscatine, IA

Built 1986 Load: 34.7 t ADT: 550

LOCAL

Fair

Over: SMALL STREAM

087361801, Sac, IA

Built 1985 Load: 34.7 t ADT: 15

K64

Fair

Over: UNNAMED CREEK

095440402, Sioux, IA

Built 1900 Load: 34.7 t ADT: 1,117

BIRCH AVE

Fair

Over: BIG SIOUX RIVER

097481404, Sioux, IA

Built 1966 Load: 34.7 t ADT: 450

FM

Fair

Over: MIDDLE BRANCH 102 RIVER

070332103, Taylor, IA

Built 1983 Load: 34.7 t ADT: 390

LOCAL

Fair

Over: CREEK

069100904, Van Buren, IA

Built 1980 Load: 34.7 t ADT: 62

FM

Fair

Over: UPPER IOWA RIVER

098070705, Winneshiek, IA

Built 1967 Load: 34.7 t ADT: 265

LOCAL

Fair

Over: WATERLOO CREEK

100062413, Allamakee, IA

Built 1983 Load: 34.7 t ADT: 295

X52-GREATRVR RD

Fair

Over: DRAINAGE DITCH

098031104, Allamakee, IA

Built 2013 Load: 34.7 t ADT: 570

RAILWAY ST

Fair

Over: ELK CREEK

000000000, Clay, IA

Built 1996 Load: 34.7 t ADT: 884

MINNESOTA AVE

Fair

Over: OVER UPRR

A66600500, Story, IA

Built 1980 Load: 34.7 t ADT: 488

ZELLER STREET

Fair

Over: MUDDY CREEK

West of Crandic RR, Johnson, IA

Built 1999 Load: 34.7 t ADT: 4,290

I-280

Fair

Over: MISSISSIPPI RIVER & ROAD

IN ROCK ISLAND, Scott, IA

Built 1970 Load: 34.7 t ADT: 24,200

EVANSDALE DR

Fair

Over: I-380

AT JCT. OF EVANSDALE DR., Black Hawk, IA

Built 1982 Load: 34.7 t ADT: 4,760

I 380 NB

Fair

Over: IANR RR TX ST CEDAR RVR

0.4 MI. S OF JCT. 218, Black Hawk, IA

Built 1983 Load: 34.7 t ADT: 19,950

PK 607(BLKHAWK)

Fair

Over: BLACK HAWK LAKE

Black Hawk Lake St. Park, Sac, IA

Built 1989 Load: 34.7 t

Co. Highway

Fair

Over: Des Moines River

Red Rock Dam, Marion, IA

Built 1967 Load: 34.7 t ADT: 3,750

NB I-35

Fair

Over: WHITE BREAST CREEK

1.3 MI. S OF JCT. US 34, Clarke, IA

Built 1969 Load: 34.8 t ADT: 8,650

IA 136

Fair

Over: DRAINAGE DITCH

8.6 mi. N of jct. US 61, Clinton, IA

Built 1952 Load: 34.8 t ADT: 1,230

EB I-80

Fair

Over: OVER IAIS RR

0.4 MILES W OF JCT IA 14, Jasper, IA

Built 1962 Load: 34.8 t ADT: 16,700

FM

Fair

Over: I-80

1.5 MI. W OF Jct. I-380, Johnson, IA

Built 1963 Load: 34.8 t ADT: 4,676

US 75 & IA 9

Fair

Over: MOON CREEK

0.5 mi. E of W jct. US 75, Lyon, IA

Built 1972 Load: 34.8 t ADT: 4,400

SB I-29

Fair

Over: BNSF RR & EATON DITCH

0.8 MI N OF S JCT. US 34, Mills, IA

Built 1970 Load: 34.8 t ADT: 6,800

IA 22 & 70

Fair

Over: WAPSINONOC CREEK

1.6 Mi. E OF W Jct. IA 70, Muscatine, IA

Built 1988 Load: 34.8 t ADT: 2,830

LOCAL

Fair

Over: CREEK

078351607, Audubon, IA

Built 1924 Load: 34.8 t ADT: 15

FM

Fair

Over: KEEVERS LAKE

073020803, Louisa, IA

Built 1988 Load: 34.8 t ADT: 70

LOCAL

Fair

Over: DRAINAGE

071381302, Montgomery, IA

Built 1992 Load: 34.8 t ADT: 45

FM

Fair

Over: STREAM

081142101, Poweshiek, IA

Built 1962 Load: 34.8 t ADT: 20

Showing 7,801-7,850 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.