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

IA 150

Fair

Over: STREAM

1.3 mi. S of Jct. SR C33, Fayette, IA

Built 1949 Load: 32.3 t ADT: 1,460

IA 9

Fair

Over: LITTLE WAPSIPINICON RVR

250 ft. W of jct. SR V10, Howard, IA

Built 1976 Load: 32.3 t ADT: 1,810

IA 136

Fair

Over: STREAM

3.5 mi. N of Jct. SR E17, Jones, IA

Built 1940 Load: 32.3 t ADT: 770

US 61

Fair

Over: MUSKRAT LAKE

4.6 mi. S of S Jct. IA 92, Louisa, IA

Built 1985 Load: 32.3 t ADT: 4,950

SB US 75

Fair

Over: DRY CREEK

2.3 mi. N of SR C60, Plymouth, IA

Built 1948 Load: 32.3 t ADT: 7,000

SB US 75

Fair

Over: DRY CREEK

1.5 mi. S of SR C44, Plymouth, IA

Built 1948 Load: 32.3 t ADT: 7,000

IA 4

Fair

Over: DRAINAGE DITCH

1.5 mi. N of jct SR C56, Pocahontas, IA

Built 1991 Load: 32.3 t ADT: 2,420

IA 461

Fair

Over: GOOSE CREEK

1.3 MI. N OF JCT. US 6, Scott, IA

Built 1951 Load: 32.3 t ADT: 17,300

IA 2

Fair

Over: EAST 102 RIVER

At Jct. SR N-44, Taylor, IA

Built 1978 Load: 32.3 t ADT: 1,130

RAMP IA 12

Fair

Over: RAMP OFF IA 12 TO IA 376

At EB IA 12 and SB US 376, Woodbury, IA

Built 1967 Load: 32.3 t ADT: 3,220

ASHLEY RD

Fair

Over: TRIB TO CEDAR RIVER

87-11-07-03-10, Black Hawk, IA

Built 1983 Load: 32.3 t ADT: 44

JONQUIL AVE

Fair

Over: WEST FORK BEAVER DAM CR

094211502, Cerro Gordo, IA

Built 1981 Load: 32.3 t ADT: 147

KILLDEER

Fair

Over: CALMUS CREEK

097212602, Cerro Gordo, IA

Built 1981 Load: 32.3 t ADT: 628

420TH ST

Fair

Over: WILLOW CREEK

095382201, Clay, IA

Built 1978 Load: 32.3 t ADT: 11

290TH AVE

Fair

Over: STREAM

096352002, Clay, IA

Built 1994 Load: 32.3 t ADT: 103

380TH ST

Fair

Over: PRAIRIE CK

096363301, Clay, IA

Built 1977 Load: 32.3 t ADT: 30

330TH ST

Fair

Over: STREAM

096380201, Clay, IA

Built 1900 Load: 32.3 t ADT: 123

FM 350TH ST

Fair

Over: DRAINAGE

096381701, Clay, IA

Built 1972 Load: 32.3 t ADT: 908

FM 100TH AVE

Fair

Over: STREAM

096381802, Clay, IA

Built 1972 Load: 32.3 t ADT: 529

352ND ST

Fair

Over: STREAM

091021003, Clayton, IA

Built 1998 Load: 32.3 t ADT: 41

160TH ST

Fair

Over: STREAM

094060403, Clayton, IA

Built 1981 Load: 32.3 t ADT: 11

FM

Fair

Over: SOAP CREEK

070131006, Davis, IA

Built 1987 Load: 32.3 t ADT: 380

GRAIN RD.

Fair

Over: UNAMED CR

093082406, Fayette, IA

Built 1998 Load: 32.3 t ADT: 20

BLUFF ROAD

Fair

Over: STREAM

067420503, Fremont, IA

Built 1960 Load: 32.3 t ADT: 249

FM

Fair

Over: TRIBUTARY TO TROUBLESOME

079330502, Guthrie, IA

Built 1951 Load: 32.3 t ADT: 199

SW 480TH ST

Fair

Over: BR DIRTY FACE CR

078071101, Johnson, IA

Built 1920 Load: 32.3 t ADT: 61

CHAMBERS AVE

Fair

Over: CLEAR CREEK

080082804, Johnson, IA

Built 1977 Load: 32.3 t ADT: 170

LINN-JOHNSON RD

Fair

Over: KNAPP CREEK

081080601, Johnson, IA

Built 1984 Load: 32.3 t ADT: 46

CHAIN BRIDGE ROAD

Fair

Over: LONE TREE CREEK

000000000, Linn, IA

Built 1984 Load: 32.3 t ADT: 171

FM

Fair

Over: CEDAR CREEK

074151405, Mahaska, IA

Built 1957 Load: 32.3 t ADT: 120

FM

Fair

Over: SMALL STREAM

083170808, Marshall, IA

Built 1984 Load: 32.3 t ADT: 157

FM

Fair

Over: NISHNABOTNA TRIB

071380901, Montgomery, IA

Built 1959 Load: 32.3 t ADT: 72

FM

Fair

Over: CREEK

098400502, Osceola, IA

Built 1966 Load: 32.3 t ADT: 71

LOCAL

Fair

Over: STREAM

098402702, Osceola, IA

Built 1976 Load: 32.3 t ADT: 41

FM

Fair

Over: WAGNER CR

098420203, Osceola, IA

Built 1974 Load: 32.3 t ADT: 71

FM

Fair

Over: RAT CREEK

098420401, Osceola, IA

Built 1990 Load: 32.3 t ADT: 578

FM

Fair

Over: KAPPES CREEK

098421204, Osceola, IA

Built 1958 Load: 32.3 t ADT: 439

FM

Fair

Over: DRY RUN

098421204, Osceola, IA

Built 1924 Load: 32.3 t ADT: 439

FM

Fair

Over: RUSH LAKE OUTLET

099401401, Osceola, IA

Built 1984 Load: 32.3 t ADT: 828

FM

Fair

Over: CREEK

099402402, Osceola, IA

Built 1967 Load: 32.3 t ADT: 569

FM

Fair

Over: POLLY CREEK

099410604, Osceola, IA

Built 1955 Load: 32.3 t ADT: 718

FM

Fair

Over: DRAINAGE DITCH

099412102, Osceola, IA

Built 1959 Load: 32.3 t ADT: 110

FM

Fair

Over: DAWSON CREEK

099412902, Osceola, IA

Built 1992 Load: 32.3 t ADT: 459

LOCAL

Fair

Over: DRY RUN

099422701, Osceola, IA

Built 1972 Load: 32.3 t ADT: 35

FM

Fair

Over: DRAINAGE

091462303, Plymouth, IA

Built 1966 Load: 32.3 t ADT: 190

FM

Fair

Over: SMALL STREAM

078402402, Shelby, IA

Built 1958 Load: 32.3 t ADT: 29

LOCAL

Fair

Over: IOWA RIVER

092242402, Wright, IA

Built 1987 Load: 32.3 t ADT: 63

LOCAL SDB

Fair

Over: DRAINAGE

085351502, Carroll, IA

Built 1940 Load: 32.3 t ADT: 45

NB US 61/151

Fair

Over: 4TH 5TH WHITE ST

0.6 mi. N of US 20, Dubuque, IA

Built 1992 Load: 32.3 t ADT: 13,200

US 71

Fair

Over: DRAINAGE DITCH

1.2 mi. N of Jct. SR J-53, Page, IA

Built 1973 Load: 32.3 t ADT: 3,000

Showing 6,201-6,250 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.