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

FM

Fair

Over: HOWARD CREEK

094052406, Clayton, IA

Built 1983 Load: 30.8 t ADT: 344

FM

Fair

Over: CREEK

080271103, Dallas, IA

Built 1969 Load: 30.8 t ADT: 399

FM

Fair

Over: SOAP CREEK

070152406, Davis, IA

Built 1973 Load: 30.8 t ADT: 80

LOCAL

Fair

Over: HAWKEYE CREEK

072021502, Des Moines, IA

Built 1966 Load: 30.8 t ADT: 62

LOCAL

Fair

Over: CREEK

095160304, Floyd, IA

Built 1984 Load: 30.8 t ADT: 78

FM S13

Fair

Over: IOWA RIVER

091223103, Franklin, IA

Built 1978 Load: 30.8 t ADT: 570

MEADOW AVE

Fair

Over: SMALL STREAM

083301806, Greene, IA

Built 1980 Load: 30.8 t ADT: 15

FM

Fair

Over: FORK OF MINNEHAHA CREEK

087160704, Grundy, IA

Built 1986 Load: 30.8 t ADT: 324

LOCAL ROAD

Fair

Over: BRANCH BLACKHAWK CRK

088173202, Grundy, IA

Built 1976 Load: 30.8 t ADT: 49

FM

Fair

Over: BLACK HAWK

088173503, Grundy, IA

Built 1981 Load: 30.8 t ADT: 79

FM

Fair

Over: BRANCH SPRING CREEK

078310906, Guthrie, IA

Built 1986 Load: 30.8 t ADT: 45

FM

Fair

Over: MASON CREEK

079322604, Guthrie, IA

Built 1987 Load: 30.8 t ADT: 50

FM

Fair

Over: IOWA RIVER

086190907, Hardin, IA

Built 1978 Load: 30.8 t ADT: 59

FM

Fair

Over: CREEK

089211105, Hardin, IA

Built 1982 Load: 30.8 t ADT: 442

FM

Fair

Over: DRAINAGE DITCH

091282702, Humboldt, IA

Built 1970 Load: 30.8 t ADT: 1,257

FM

Fair

Over: DD NO 100

093270301, Humboldt, IA

Built 1974 Load: 30.8 t ADT: 290

FM

Fair

Over: PRAIRIE CREEK

093272301, Humboldt, IA

Built 1970 Load: 30.8 t ADT: 71

FM

Fair

Over: EAST FORK BATTLE CREEK

088413603, Ida, IA

Built 1985 Load: 30.8 t ADT: 80

LOCAL

Fair

Over: MIDDLE ENGLISH R

078122302, Iowa, IA

Built 1976 Load: 30.8 t ADT: 50

LOCAL

Fair

Over: CREEK

085E50804, Jackson, IA

Built 1969 Load: 30.8 t ADT: 40

500TH ST SE

Fair

Over: STREAM

078051403, Johnson, IA

Built 1969 Load: 30.8 t ADT: 35

500TH ST

Fair

Over: STREAM

078051702, Johnson, IA

Built 1966 Load: 30.8 t ADT: 133

FM 540TH ST

Fair

Over: STREAM

078052001, Johnson, IA

Built 1955 Load: 30.8 t ADT: 880

NAPOLEON ST

Fair

Over: STREAM

078060203, Johnson, IA

Built 1972 Load: 30.8 t ADT: 388

SW OBSRVTRY AVE

Fair

Over: STREAM

078063306, Johnson, IA

Built 1973 Load: 30.8 t ADT: 72

SW JAMES AVE

Fair

Over: STREAM

078071502, Johnson, IA

Built 1960 Load: 30.8 t ADT: 41

LOCAL

Fair

Over: STREAM

078082102, Johnson, IA

Built 1966 Load: 30.8 t ADT: 61

FM

Fair

Over: STREAM

074111503, Keokuk, IA

Built 1973 Load: 30.8 t ADT: 80

INK ROAD

Fair

Over: TRIB TO ABBE CREEK

082050306, Linn, IA

Built 1987 Load: 30.8 t ADT: 128

COTTAGE GR.PWY

Fair

Over: WANATEE CREEK

083062101, Linn, IA

Built 1984 Load: 30.8 t ADT: 864

LOCAL

Fair

Over: SMALL STREAM

074051604, Louisa, IA

Built 1983 Load: 30.8 t ADT: 51

LOCAL

Fair

Over: MUSCATINE SLOUGH

075032405, Louisa, IA

Built 1981 Load: 30.8 t ADT: 41

LOCAL

Fair

Over: SMALL STREAM

075041501, Louisa, IA

Built 1966 Load: 30.8 t ADT: 82

LOCAL

Fair

Over: INDIAN CREEK

075042503, Louisa, IA

Built 1982 Load: 30.8 t ADT: 51

LOCAL

Fair

Over: SHORT CREEK

075050602, Louisa, IA

Built 1969 Load: 30.8 t ADT: 30

FM

Fair

Over: BR OF CHARITON RIVER

071201902, Lucas, IA

Built 1970 Load: 30.8 t ADT: 50

FM

Fair

Over: CEDAR CREEK

076260804, Madison, IA

Built 1984 Load: 30.8 t ADT: 60

FM

Fair

Over: MUD CREEK

085192006, Marshall, IA

Built 1981 Load: 30.8 t ADT: 255

NOBLE AVE

Fair

Over: SPRING CREEK

098162902, Mitchell, IA

Built 1977 Load: 30.8 t ADT: 59

410TH

Fair

Over: BURR OAK CREEK

099163101, Mitchell, IA

Built 1975 Load: 30.8 t ADT: 30

FM

Fair

Over: WAPSIE CREEK

078042002, Muscatine, IA

Built 1967 Load: 30.8 t ADT: 60

FREMONT AVE

Fair

Over: FISHER CREEK

068390702, Page, IA

Built 1985 Load: 30.8 t ADT: 41

LOCAL

Fair

Over: DD NO 98

094321901, Palo Alto, IA

Built 1974 Load: 30.8 t ADT: 26

FM

Fair

Over: DD 63

094332702, Palo Alto, IA

Built 1972 Load: 30.8 t ADT: 60

LOCAL

Fair

Over: DD 63

094332802, Palo Alto, IA

Built 1977 Load: 30.8 t ADT: 11

FM

Fair

Over: CREEK

095311401, Palo Alto, IA

Built 1965 Load: 30.8 t ADT: 60

440TH AVE

Fair

Over: STREAM

096332302, Palo Alto, IA

Built 1972 Load: 30.8 t ADT: 82

FM

Fair

Over: DD

096332902, Palo Alto, IA

Built 1976 Load: 30.8 t ADT: 41

LOCAL

Fair

Over: STREAM

096333002, Palo Alto, IA

Built 1972 Load: 30.8 t ADT: 21

FM

Fair

Over: LIZARD CK DD #53

091320504, Pocahontas, IA

Built 1980 Load: 30.8 t ADT: 170

Showing 5,751-5,800 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.