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: SMALL CREEK

098091602, Winneshiek, IA

Built 1985 Load: 35.0 t ADT: 20

YANKEE AVE

Fair

Over: DD #29

090232305, Wright, IA

Built 1978 Load: 35.0 t ADT: 35

LOCAL

Fair

Over: DD #29

090232304, Wright, IA

Built 1978 Load: 35.0 t ADT: 35

RUSTY WALACE DR

Fair

Over: SMALL STREAM

000000000, Jasper, IA

Built 1998 Load: 35.0 t ADT: 600

FM

Fair

Over: SMALL STREAM

085E22403, Jackson, IA

Built 1998 Load: 35.0 t ADT: 630

LOCAL

Fair

Over: SMALL

096460701, Sioux, IA

Built 1954 Load: 35.0 t ADT: 110

WISCONSIN AVE

Fair

Over: CARDINAL CREEK

000000000, Scott, IA

Built 1960 Load: 35.0 t ADT: 930

NB US 61

Fair

Over: WAPSIPINICON RIVER

2.4 mi. N of SR F33, Scott, IA

Built 1981 Load: 35.0 t ADT: 8,800

SB US 218

Fair

Over: GOOSE CREEK

6.6 MI. N OF JCT. IA 92, Washington, IA

Built 1984 Load: 35.0 t ADT: 7,450

US 218 SB

Fair

Over: ENGLISH RIVER

0.6 MI. S OF JCT. IA 22, Washington, IA

Built 1984 Load: 35.0 t ADT: 7,450

SOUTH MAIN ST

Fair

Over: U.S. 61

At jct. U.S. 61, Jackson, IA

Built 1996 Load: 35.0 t ADT: 3,211

6TH ST

Fair

Over: FLOYD CLARK & RR

000000000, Woodbury, IA

Built 1965 Load: 35.1 t ADT: 8,520

SB 218 EB 57

Fair

Over: CEDAR RIVER OVERFLOW

0.2 mi. E of jct. IA 27, Black Hawk, IA

Built 1974 Load: 35.1 t ADT: 9,800

IA 17

Fair

Over: MONTGOMERY CREEK

2.6 MILES S OF JCT SR E18, Boone, IA

Built 1979 Load: 35.1 t ADT: 2,260

X-40

Fair

Over: I-80

7.2 mi. W of Jct. Iowa 38, Cedar, IA

Built 1960 Load: 35.1 t ADT: 3,210

SB I-29

Fair

Over: OVER UP RR

0.4 mi. N of Jct. U.S. 30, Harrison, IA

Built 1967 Load: 35.1 t ADT: 7,750

US 218 NB

Fair

Over: NORTH FISH CREEK

1.1 mi. N of Jct. SR J20, Henry, IA

Built 1963 Load: 35.1 t ADT: 4,850

IA 92

Fair

Over: MAIN ST & COLLINS RD

0.3 mi W of Jct. IA 70, Louisa, IA

Built 1995 Load: 35.1 t ADT: 3,100

US 34

Fair

Over: LITTLE TARKIO CREEK

0.2 MI. E of SR M63, Montgomery, IA

Built 1964 Load: 35.1 t ADT: 2,880

IA 48

Fair

Over: OVERFLOW NISHNABOTNA

2.0 mi. S of Jct. SR H14, Montgomery, IA

Built 1973 Load: 35.1 t ADT: 1,210

IA 2

Fair

Over: JACKSON CREEK

3.8 MI. W OF Jct. SR S56, Wayne, IA

Built 1962 Load: 35.1 t ADT: 2,160

LOCAL

Fair

Over: CREEK

088010902, Dubuque, IA

Built 1900 Load: 35.1 t ADT: 49

LOCAL

Fair

Over: STREAM

080310901, Guthrie, IA

Built 1968 Load: 35.1 t ADT: 50

FM

Fair

Over: DRAINAGE DITCH

091292101, Humboldt, IA

Built 1958 Load: 35.1 t ADT: 170

FM

Fair

Over: STREAM

079131707, Poweshiek, IA

Built 1975 Load: 35.1 t ADT: 20

670TH AVE

Fair

Over: EAST INDIAN CREEK

084221202, Story, IA

Built 1915 Load: 35.1 t ADT: 26

LOCAL

Fair

Over: STREAM

071290701, Union, IA

Built 1965 Load: 35.1 t ADT: 46

FM

Fair

Over: WILLOW CREEK

811439, Shelby, IA

Built 1969 Load: 35.1 t ADT: 887

LOCAL

Fair

Over: CALEB CREEK

068230301, Wayne, IA

Built 1993 Load: 35.1 t ADT: 15

EB US 20

Fair

Over: US 63 SERGEANT RD TRAIL

AT JCT. US 63, Black Hawk, IA

Built 1983 Load: 35.1 t ADT: 11,450

SB I-35

Fair

Over: OVER UPP RR

1.1 MILES N OF N JCT I-80, Polk, IA

Built 2002 Load: 35.1 t ADT: 45,700

IA 25

Fair

Over: STREAM

2.3 MI. N OF N JCT SR J23, Ringgold, IA

Built 1934 Load: 35.2 t ADT: 1,250

SB I-35

Fair

Over: BIKE PATH

1.1 MI. N OF JCT. IA 210, Story, IA

Built 1964 Load: 35.2 t ADT: 23,300

DYSART RD

Fair

Over: TRIB TO MILLER CREEK

88-12-19-04-10, Black Hawk, IA

Built 1981 Load: 35.2 t ADT: 1,463

FM

Fair

Over: HICKORY CREEK

067130506, Davis, IA

Built 1976 Load: 35.2 t ADT: 290

LOC 60TH AVE

Fair

Over: PRAIRIE CREEK

098301202, Kossuth, IA

Built 1990 Load: 35.2 t ADT: 41

FM

Fair

Over: MCCANDLESS CLEGHORN D D

083452801, Monona, IA

Built 1969 Load: 35.2 t ADT: 45

OLD STAGE RD

Fair

Over: CREEK

098082407, Winneshiek, IA

Built 2001 Load: 35.2 t ADT: 1,051

CLARK ST

Fair

Over: IA 163

2.5 MI. E OF SR G-28., Marion, IA

Built 1994 Load: 35.2 t ADT: 6,400

IA 13

Fair

Over: BRANCH MAQUOKETA RIVER

0.9 mi N of N jct. SR D47, Delaware, IA

Built 1975 Load: 35.3 t ADT: 4,840

I 29 NB

Fair

Over: US 30

AT JCT. US 30, Harrison, IA

Built 1967 Load: 35.3 t ADT: 7,500

WB I-80

Fair

Over: SOUTH SKUNK RIVER

2.5 mi. W of JCT 117, Jasper, IA

Built 1960 Load: 35.3 t ADT: 18,050

EB I-80

Fair

Over: PRAIRIE CREEK

4.3 MILES E OF JCT IA 117, Jasper, IA

Built 1961 Load: 35.3 t ADT: 16,700

IA 1

Fair

Over: MIDDLE WALNUT CREEK

3.2 mi. S of S Jct. IA 78, Jefferson, IA

Built 1969 Load: 35.3 t ADT: 2,560

E15 115TH ST

Fair

Over: I-35

AT JUNCTION SR E15, Story, IA

Built 1965 Load: 35.3 t ADT: 4,079

LOCAL

Fair

Over: BRANCH WATERLOO CREEK

100061306, Allamakee, IA

Built 1960 Load: 35.3 t ADT: 39

LOCAL

Fair

Over: CREEK

078360603, Audubon, IA

Built 1973 Load: 35.3 t ADT: 51

FM 260TH AVE

Fair

Over: MONTGOMERY CREEK

094360202, Clay, IA

Built 1978 Load: 35.3 t ADT: 71

160TH ST.

Fair

Over: DD #12

082E20501, Clinton, IA

Built 1979 Load: 35.3 t ADT: 35

175TH ST

Fair

Over: DRAINAGE DITCH #12

082E21105, Clinton, IA

Built 1980 Load: 35.3 t ADT: 16

Showing 7,901-7,950 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.