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

PIONEER AVE

Good

Over: SILVER CREEK

088390202, Ida, IA

Built 2018 Load: 34.0 t ADT: 11

LOCAL

Good

Over: SILVER CREEK

089401501, Ida, IA

Built 2003 Load: 34.0 t ADT: 62

LOCAL

Good

Over: BITTER CREEK

089411604, Ida, IA

Built 2004 Load: 34.0 t ADT: 15

MAHOGANY AVE

Good

Over: DRAINAGE

072090604, Jefferson, IA

Built 2017 Load: 34.0 t ADT: 70

LOCAL

Good

Over: BR LITTLE WHITEBREAST

072210403, Lucas, IA

Built 2002 Load: 34.0 t ADT: 26

HEDGE AVE

Good

Over: PERRY CREEK

9147250210, Plymouth, IA

Built 2014 Load: 34.0 t ADT: 30

NE 3RD ST

Good

Over: CREEK

0.13 Mi. N. of NE 6 Ave., Polk, IA

Built 2020 Load: 34.0 t ADT: 2,521

NE 118TH AVE

Good

Over: BRANCH SKUNK RIVER

080220301, Polk, IA

Built 2000 Load: 34.0 t ADT: 45

NW 134TH AVE

Good

Over: FOUR MILE CREEK

0.2 mi E of NW 2nd St, Polk, IA

Built 2021 Load: 34.0 t ADT: 180

G30 PINOAK RD

Good

Over: SILVER CREEK

076411201, Pottawattamie, IA

Built 2014 Load: 34.0 t ADT: 219

BETTIN AVE

Good

Over: STREAM

089380402, Sac, IA

Built 2017 Load: 34.0 t ADT: 5

L14 KINGBIRD AVE

Good

Over: NO NAME CREEK

096431802, Sioux, IA

Built 2016 Load: 34.0 t ADT: 578

FM

Good

Over: NO NAME CREEK

097431101, Sioux, IA

Built 1965 Load: 34.0 t ADT: 609

E63 305TH ST

Good

Over: CALAMUS CREEK

0.3 Mi E S14, Story, IA

Built 2016 Load: 34.0 t ADT: 90

FM

Good

Over: LITTLE CEDAR CREEK

069080302, Van Buren, IA

Built 1993 Load: 34.0 t ADT: 420

110TH AVE

Good

Over: LITTLE CEDAR CREEK

072130402, Wapello, IA

Built 2017 Load: 34.0 t ADT: 47

307TH AVE

Good

Over: CREEK

0.5 MI S of 240 St., Winneshiek, IA

Built 2019 Load: 34.0 t ADT: 50

200TH ST

Good

Over: STREAM

088422501, Woodbury, IA

Built 2018 Load: 34.0 t ADT: 15

WALNUT ST

Good

Over: CREEK

088462901, Woodbury, IA

Built 2014 Load: 34.0 t ADT: 450

LOCAL

Good

Over: SMALL

094471802, Sioux, IA

Built 1960 Load: 34.0 t ADT: 11

LOCAL

Good

Over: UPPER IOWA RIVER

000053511, Allamakee, IA

Built 2004 Load: 34.0 t ADT: 690

LILY AVE

Good

Over: SMALL

096432202, Sioux, IA

Built 2008 Load: 34.0 t ADT: 270

KINGBIRD AVE

Good

Over: SMALL

096433002, Sioux, IA

Built 2010 Load: 34.0 t ADT: 578

M44 105TH AVE

Good

Over: POOR FARM CREEK

091372704, Buena Vista, IA

Built 2017 Load: 34.0 t ADT: 2,414

310TH ST

Good

Over: STREAM

24000 block of 310th St., Cerro Gordo, IA

Built 2021 Load: 34.0 t ADT: 15

142ND ST

Good

Over: WALNUT CREEK

O57000543, Polk, IA

Built 2006 Load: 34.0 t ADT: 3,538

CEDAR RIVER PKWY

Good

Over: CEDAR RIVER

000000000, Bremer, IA

Built 2019 Load: 34.0 t ADT: 144

LONE TREE RD

Good

Over: US 218

1.7 mi N of IA 57 & IA 58, Black Hawk, IA

Built 1995 Load: 34.0 t ADT: 2,358

EMMONS ST

Good

Over: I-380

0.9 MI. N OF JCT. 100, Linn, IA

Built 1980 Load: 34.0 t ADT: 3,500

BOAR RD

Good

Over: I-380

1.6 MI. S OF S.R. W36, Linn, IA

Built 1983 Load: 34.0 t ADT: 39

US 20 EB

Good

Over: SR T55

AT JUNCTION WITH SR T55, Grundy, IA

Built 2000 Load: 34.0 t ADT: 6,500

US 20 WB

Good

Over: IA 14

AT JUNCTION WITH IA 14, Grundy, IA

Built 2000 Load: 34.0 t ADT: 4,400

IA 27 SB

Good

Over: 295TH ST AND BNSF RR

0.5 mi. N of SR J72, Lee, IA

Built 2001 Load: 34.0 t ADT: 3,600

IA 376 RAMP

Good

Over: DRAINAGE

0.1 mi. N of SR D12, Woodbury, IA

Built 2001 Load: 34.0 t ADT: 1,560

US67 TO I74 RAMP

Good

Over: MISSISSIPPI BLVD

4.3 MI. S OF JCT. I-80, Scott, IA

Built 2019 Load: 34.0 t ADT: 5,100

I380 SB TO I80 EB

Good

Over: I 80 RAMPS E & G

I-80 / I-380 INTERCHANGE, Johnson, IA

Built 2022 Load: 34.0 t ADT: 14,400

FM

Good

Over: MIDDLE NODAWAY RIVER

074332460, Adair, IA

Built 1978 Load: 34.1 t ADT: 249

WARBLER

Good

Over: BEAVER CREEK

095192302, Cerro Gordo, IA

Built 1990 Load: 34.1 t ADT: 26

180 ST

Good

Over: DRAINAGE DITCH

082E11601, Clinton, IA

Built 2000 Load: 34.1 t ADT: 350

130TH ST.

Good

Over: SMALL

083E62301, Clinton, IA

Built 1993 Load: 34.1 t ADT: 25

FM GENEVA PLACE

Good

Over: SOLDIER RIVER

081442705, Harrison, IA

Built 1980 Load: 34.1 t ADT: 50

LOC 40TH AVE

Good

Over: BLACK CAT CREEK

097302202, Kossuth, IA

Built 1986 Load: 34.1 t ADT: 26

LOCAL

Good

Over: FLOYD RIVER

097411102, O'Brien, IA

Built 1986 Load: 34.1 t ADT: 50

NATURE AVE

Good

Over: BIG WHISKEY CREEK

091451302, Plymouth, IA

Built 1995 Load: 34.1 t ADT: 11

420TH AVE

Good

Over: BR NORTH ENGLISH RIVER

079160101, Poweshiek, IA

Built 2023 Load: 34.1 t ADT: 30

400TH AVE

Good

Over: STREAM

080163001, Poweshiek, IA

Built 2020 Load: 34.1 t ADT: 100

LOCAL

Good

Over: SM STREAM

097461201, Sioux, IA

Built 1931 Load: 34.1 t ADT: 61

G AVE

Good

Over: ABES FORK

082153102, Tama, IA

Built 2016 Load: 34.1 t ADT: 15

NB I-380

Good

Over: EAST BLUE CREEK

2.3 mi. N of Jct. SR W35, Linn, IA

Built 1982 Load: 34.1 t ADT: 10,750

30TH AVE

Good

Over: I-380

1.5 MILES N OF JCT IA 150, Benton, IA

Built 1984 Load: 34.1 t ADT: 25

Showing 14,351-14,400 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.