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

DURANGO WAY

Fair

Over: I-80

0.6 Mi.W of SR P-53 & F60, Dallas, IA

Built 1960 Load: 26.1 t ADT: 123

SB I-35

Fair

Over: 324TH STREET

AT MISSOURI ST LINE, Decatur, IA

Built 1970 Load: 26.1 t ADT: 6,900

IA 14

Fair

Over: WHITE BREAST CREEK

2.1 MI. S OF Jct. SR G40, Marion, IA

Built 1965 Load: 26.1 t ADT: 3,120

I 29 SB

Fair

Over: 25TH ST

1.0 MI. S OF IA 192, Pottawattamie, IA

Built 1967 Load: 26.1 t ADT: 5,400

I 29 NB

Fair

Over: I 880

AT N Jct. I-880, Pottawattamie, IA

Built 1966 Load: 26.1 t ADT: 9,750

CO RD Y-68

Fair

Over: CROW CREEK

079E32503, Scott, IA

Built 1954 Load: 26.1 t ADT: 1,680

LOCAL MUNI RD

Fair

Over: SMALL NATURAL STREAM

079E32404, Scott, IA

Built 1954 Load: 26.1 t ADT: 2,085

CO RD 105

Fair

Over: DRAINAGE DITCH

100203101, Worth, IA

Built 1949 Load: 26.1 t ADT: 1,414

VERMONT AVE

Fair

Over: SMALL

082011502, Cedar, IA

Built 2005 Load: 26.1 t ADT: 60

FM

Fair

Over: HOCKETT CREEK

083371901, Crawford, IA

Built 2006 Load: 26.1 t ADT: 20

LOCAL

Fair

Over: SMALL STREAM

085382803, Crawford, IA

Built 2006 Load: 26.1 t ADT: 15

FM & 170TH ST

Fair

Over: E.PICAYUNE CREEK

080410305, Harrison, IA

Built 1978 Load: 26.1 t ADT: 15

FM

Fair

Over: DD

093293302, Humboldt, IA

Built 1925 Load: 26.1 t ADT: 339

LOG AVE

Fair

Over: WEST RAT CREEK

098431402, Lyon, IA

Built 1900 Load: 26.1 t ADT: 34

LOCAL ROAD

Fair

Over: TAFT CREEK

099432302, Lyon, IA

Built 1900 Load: 26.1 t ADT: 30

LOCAL ROAD

Fair

Over: SMALL STREAM

100431501, Lyon, IA

Built 1900 Load: 26.1 t ADT: 15

LOCAL

Fair

Over: TOM CREEK

077292304, Madison, IA

Built 1987 Load: 26.1 t ADT: 11

LOCAL RD

Fair

Over: WHITE CREEK

072192309, Monroe, IA

Built 1959 Load: 26.1 t ADT: 26

FM

Fair

Over: EAST TARKIO

071373501, Montgomery, IA

Built 1969 Load: 26.1 t ADT: 45

WHIPPERWILL RD

Fair

Over: STREAM

077420901, Pottawattamie, IA

Built 2003 Load: 26.1 t ADT: 30

FM

Fair

Over: BRANCH OF IOWA RIVER

082151203, Tama, IA

Built 1936 Load: 26.1 t ADT: 491

LOCAL

Fair

Over: DEER CREEK

085163003, Tama, IA

Built 1940 Load: 26.1 t ADT: 11

LOCAL

Fair

Over: STREAM

086450301, Woodbury, IA

Built 1999 Load: 26.1 t ADT: 40

ANSBOROUGH AVE

Fair

Over: BLACK HAWK CREEK

CITY BRIDGE NO. 17, Black Hawk, IA

Built 1971 Load: 26.2 t ADT: 8,392

IA 83

Fair

Over: EAST NISHNABOTNA RIVER

2.1 mi. E of jct. IA 173, Cass, IA

Built 1934 Load: 26.2 t ADT: 3,690

US 52

Fair

Over: DRAINAGE DITCH

7.4 mi S of jct US 61/151, Dubuque, IA

Built 1945 Load: 26.2 t ADT: 3,340

NB I-29

Fair

Over: DRAINAGE DITCH

1.6 MI. N OF Jct. SR F-20, Harrison, IA

Built 1966 Load: 26.2 t ADT: 7,250

SB I-29

Fair

Over: DRAINAGE DITCH

1.6 Mi. N of Jct. SR F-20, Harrison, IA

Built 1966 Load: 26.2 t ADT: 7,250

IA 175

Fair

Over: BRANCH ODEBOLT RIVER

2.5 mi. W of Jct. SR M31, Ida, IA

Built 1939 Load: 26.2 t ADT: 2,080

IA 175

Fair

Over: DRAINAGE DITCH

3.0 mi. E of S.R. L12, Monona, IA

Built 1964 Load: 26.2 t ADT: 2,120

LOCAL

Fair

Over: PAINT CREEK

097051204, Allamakee, IA

Built 1975 Load: 26.2 t ADT: 33

LOCAL

Fair

Over: CREEK

079351006, Audubon, IA

Built 1966 Load: 26.2 t ADT: 11

LOCAL

Fair

Over: BR LITTLE ELKHORN CR

079011602, Cedar, IA

Built 1946 Load: 26.2 t ADT: 11

FM-530TH ST.

Fair

Over: WILLOW CREEK

092413101, Cherokee, IA

Built 1968 Load: 26.2 t ADT: 898

LACE AVE

Fair

Over: SM STREAM

093032506, Clayton, IA

Built 1955 Load: 26.2 t ADT: 79

KEYSTONE RD

Fair

Over: STREAM

094031605, Clayton, IA

Built 1958 Load: 26.2 t ADT: 30

160TH ST

Fair

Over: DEER CREEK

094060102, Clayton, IA

Built 1958 Load: 26.2 t ADT: 51

CHARIOT RD

Fair

Over: SMALL STREAM

094063510, Clayton, IA

Built 1956 Load: 26.2 t ADT: 49

DIPLOMAT RD

Fair

Over: HICKORY CREEK

095050610, Clayton, IA

Built 1953 Load: 26.2 t ADT: 511

DOLPHIN AVE

Fair

Over: STREAM

095052004, Clayton, IA

Built 1953 Load: 26.2 t ADT: 88

EAGLE RD

Fair

Over: STREAM

095053306, Clayton, IA

Built 1955 Load: 26.2 t ADT: 69

LOCAL

Fair

Over: SOUTH WILLOW CREEK

082411801, Crawford, IA

Built 1976 Load: 26.2 t ADT: 15

FM

Fair

Over: BEAVER CREEK

081270904, Dallas, IA

Built 1962 Load: 26.2 t ADT: 488

FM RIDGE RD

Fair

Over: ALLISON CREEK

088042603, Delaware, IA

Built 2003 Load: 26.2 t ADT: 44

LOCAL

Fair

Over: SMALL

090E12405, Dubuque, IA

Built 1979 Load: 26.2 t ADT: 60

930 140TH ST

Fair

Over: WEST OTTER CREEK DD 26

094251501, Hancock, IA

Built 1975 Load: 26.2 t ADT: 21

LOCAL

Fair

Over: SMALL CREEK

086E10906, Jackson, IA

Built 1992 Load: 26.2 t ADT: 78

FM 120TH ST

Fair

Over: HOOSIER CREEK

081060509, Johnson, IA

Built 1900 Load: 26.2 t ADT: 1,500

TROY MILLS RD

Fair

Over: WAPSIPINICON RIVER

086070522, Linn, IA

Built 1951 Load: 26.2 t ADT: 2,033

FM

Fair

Over: SMALL STREAM

076182206, Marion, IA

Built 1960 Load: 26.2 t ADT: 3,550

Showing 4,001-4,050 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.