State profile · Above national median SD

Iowa bridge safety

Condition ratings, load ratings, and structural-deficiency data for every public highway bridge in Iowa — drawn straight from the FHWA National Bridge Inventory.

20,753
Public bridges
36.5%
Good condition
20.0%
Poor condition
20.0%
Structurally deficient

Total Bridges

20,753

Public highway bridges in Iowa

Good Condition

36.5%

7,582 bridges rated 7-9

-13.5pp vs 50% benchmark

Poor Condition

20.0%

4,153 bridges rated 0-4

Structurally Deficient

20.0%

4,153 bridges flagged for repair priority

13.0pp vs national avg 7.0%

Iowa vs national bridge condition

Iowa — Good condition share 36.5%
National avg

Share of bridges rated 7-9 on the FHWA 0-9 scale (deck, superstructure, substructure all good).

Iowa — Structurally deficient share 66.7%
National avg

Lower is better. Bar maxes at 30% (worst-state ceiling). National average sits at 7.0%.

Condition Distribution

Bridge inventory deck-condition mix — Iowa (FHWA NBI)

Iowa36.534476943092564%38.39444899532597%20.011564593070883%20.011564593070883%GoodFairPoorStructurally Deficient
Bridge inventory deck-condition mix — Iowa (FHWA NBI)

Counties (99)

Adair 208 Adams 147 Allamakee 170 Appanoose 159 Audubon 161 Benton 327 Black Hawk 411 Boone 119 Bremer 220 Buchanan 281 Buena Vista 140 Butler 261 Calhoun 171 Carroll 223 Cass 237 Cedar 265 Cerro Gordo 210 Cherokee 223 Chickasaw 268 Clarke 150 Clay 138 Clayton 214 Clinton 325 Crawford 242 Dallas 154 Davis 156 Decatur 178 Delaware 254 Des Moines 156 Dickinson 73 Dubuque 304 Emmet 70 Fayette 288 Floyd 195 Franklin 214 Fremont 133 Greene 150 Grundy 270 Guthrie 236 Hamilton 134 Hancock 128 Hardin 211 Harrison 162 Henry 144 Howard 193 Humboldt 70 Ida 164 Iowa 189 Jackson 209 Jasper 321 Jefferson 142 Johnson 317 Jones 215 Keokuk 152 Kossuth 256 Lee 185 Linn 428 Louisa 134 Lucas 186 Lyon 241 Madison 221 Mahaska 219 Marion 204 Marshall 283 Mills 170 Mitchell 160 Monona 125 Monroe 126 Montgomery 184 Muscatine 127 O'Brien 229 Osceola 176 Page 185 Palo Alto 114 Plymouth 407 Pocahontas 186 Polk 415 Pottawattamie 469 Poweshiek 221 Ringgold 206 Sac 188 Scott 212 Shelby 194 Sioux 429 Story 262 Tama 307 Taylor 220 Union 153 Van Buren 142 Wapello 160 Warren 231 Washington 203 Wayne 163 Webster 179 Winnebago 48 Winneshiek 317 Woodbury 379 Worth 89 Wright 168

Iowa vs nearby ranks

Adjacent states on the structurally deficient leaderboard (lower share = better)

States are ranked by share of bridges flagged structurally deficient — the FHWA classification for any span where deck, superstructure, or substructure carries a condition rating of 4 or below. Lower percentages indicate stronger maintenance funding and inspection follow-through. States here sit immediately above and below Iowa on the same metric.

54

West Virginia

16.02% top marginal rate
Structure
Progressive
Burden @ $100K
$7,679

46

South Dakota

16.24% top marginal rate
Structure
Progressive
Burden @ $100K
$5,905
Selected

19

Iowa

20.01% top marginal rate
Structure
Progressive
Burden @ $100K
$20,753

78

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 composite NBI rating. Each is inspected at least every 24 months.

270TH STREET

Structurally Deficient

Over: ROSE BRANCH

071343401, Adams, IA

Built 1976 Load: 2.7 t ADT: 79

LOCAL

Poor

Over: CREEK

078342601, Audubon, IA

Built 1935 Load: 2.7 t ADT: 21

KLINE RD

Structurally Deficient

Over: MUD CREEK

87-12-15-02-10, Black Hawk, IA

Built 1948 Load: 2.7 t ADT: 11

LOCAL - 700TH

Structurally Deficient

Over: TRIB TROUBLESOME CREEK

077351402, Cass, IA

Built 1983 Load: 2.7 t ADT: 11

LOCAL - DAYTONA

Structurally Deficient

Over: BUCK CREEK

077361903, Cass, IA

Built 1980 Load: 2.7 t ADT: 35

100TH ST.

Structurally Deficient

Over: UNION CREEK

083E20101, Clinton, IA

Built 1900 Load: 2.7 t ADT: 78

All Bridges in Iowa

190TH STREET

Fair

Over: EAST TARKIO CREEK

069382401, Page, IA

Built 1972 Load: 30.6 t ADT: 50

440TH AVE

Fair

Over: SIDE DITCH BRIDGE

2.0 mi. W of W jct. IA 4, Palo Alto, IA

Built 1965 Load: 30.6 t ADT: 10

FM

Fair

Over: CYLINDER CREEK

094310901, Palo Alto, IA

Built 1987 Load: 30.6 t ADT: 45

LOCAL

Fair

Over: DD 98

094323011, Palo Alto, IA

Built 1977 Load: 30.6 t ADT: 5

FM

Fair

Over: MINK CREEK

093462801, Plymouth, IA

Built 1967 Load: 30.6 t ADT: 190

LOCAL

Fair

Over: LIZARD CREEK

090310402, Pocahontas, IA

Built 1977 Load: 30.6 t ADT: 20

LOCAL

Fair

Over: SO LIZARD CK - DD 22

090313301, Pocahontas, IA

Built 1974 Load: 30.6 t ADT: 34

LOCAL RD

Fair

Over: SO LIZARD CREEK

090320502, Pocahontas, IA

Built 1978 Load: 30.6 t ADT: 20

LOCAL

Fair

Over: SO LIZARD CR DD#22

090322201, Pocahontas, IA

Built 1978 Load: 30.6 t ADT: 26

FM

Fair

Over: PILOT CREEK

092310106, Pocahontas, IA

Built 1969 Load: 30.6 t ADT: 379

LOCAL

Fair

Over: N LIZARD CK

092321801, Pocahontas, IA

Built 1971 Load: 30.6 t ADT: 11

LOCAL

Fair

Over: BEAVER CREEK

093313504, Pocahontas, IA

Built 1973 Load: 30.6 t ADT: 40

US 59

Fair

Over: DRAINAGE DITCH

2.4 MI. N OF N JCT. US 6, Pottawattamie, IA

Built 1930 Load: 30.6 t ADT: 1,780

IA 21

Fair

Over: NORTH ENGLISH RIVER

3.5 MI. S OF JCT. I-80, Poweshiek, IA

Built 1962 Load: 30.6 t ADT: 1,730

LOCAL

Fair

Over: LOTTS CREEK

068293603, Ringgold, IA

Built 1965 Load: 30.6 t ADT: 29

LOCAL

Fair

Over: STREAM

086372306, Sac, IA

Built 1973 Load: 30.6 t ADT: 30

FM

Fair

Over: RACCOON RIVER

087353201, Sac, IA

Built 1974 Load: 30.6 t ADT: 150

LOCAL

Fair

Over: CEDAR CREEK

088362508, Sac, IA

Built 1987 Load: 30.6 t ADT: 230

I-74 (WB)

Fair

Over: DUCK CREEK AND BIKE PATH

3.1 MI. E OF JCT. I-80, Scott, IA

Built 1971 Load: 30.6 t ADT: 28,450

I-74 (EB)

Fair

Over: DUCK CREEK AND BIKE PATH

3.1 MI. E OF JCT I-80, Scott, IA

Built 1971 Load: 30.6 t ADT: 28,450

70TH AVE

Fair

Over: CREEK

080E21702, Scott, IA

Built 1968 Load: 30.6 t ADT: 26

FM

Fair

Over: TWELVE MILE CREEK

086152301, Tama, IA

Built 1981 Load: 30.6 t ADT: 196

FM

Fair

Over: BRANCH WOLF CREEK

086152904, Tama, IA

Built 1970 Load: 30.6 t ADT: 530

FM

Fair

Over: THREE MILE CREEK

072291304, Union, IA

Built 1976 Load: 30.6 t ADT: 71

LOCAL

Fair

Over: TWELVE MILE CREEK

072292001, Union, IA

Built 1977 Load: 30.6 t ADT: 103

LOCAL

Fair

Over: COMPETINE CR

073122503, Wapello, IA

Built 1975 Load: 30.6 t ADT: 47

FM

Fair

Over: MILLER CREEK

073150704, Wapello, IA

Built 1962 Load: 30.6 t ADT: 2,900

SB IA 376

Fair

Over: DRY CREEK

0.1 mi N of SR D12, Woodbury, IA

Built 1956 Load: 30.6 t ADT: 3,750

FM

Fair

Over: DRAINAGE DITCH

087462201, Woodbury, IA

Built 1974 Load: 30.6 t ADT: 279

LOCAL

Fair

Over: PRAIRIE CREEK

083110502, Benton, IA

Built 1958 Load: 30.7 t ADT: 45

FM

Fair

Over: STEIN CREEK

084122301, Benton, IA

Built 1969 Load: 30.7 t ADT: 130

FM

Fair

Over: PRATT CREEK

086112802, Benton, IA

Built 1958 Load: 30.7 t ADT: 30

IA 3

Fair

Over: CRAINS CREEK

3.4 MI. E OF JCT. 63, Bremer, IA

Built 1958 Load: 30.7 t ADT: 2,830

IA 3

Fair

Over: SHELL ROCK RIVER

0.1 MI. W OF SHELL ROCK, Butler, IA

Built 1967 Load: 30.7 t ADT: 3,540

LOCAL

Fair

Over: BR SQUAW CREEK

073262504, Clarke, IA

Built 1979 Load: 30.7 t ADT: 20

GRAHAM RD

Fair

Over: STREAM

091023008, Clayton, IA

Built 1918 Load: 30.7 t ADT: 62

318TH ST

Fair

Over: COX CREEK

092052004, Clayton, IA

Built 1920 Load: 30.7 t ADT: 30

DELTA AVE

Fair

Over: STREAM

093051804, Clayton, IA

Built 1905 Load: 30.7 t ADT: 16

LOCAL

Fair

Over: JIM CREEK

078293106, Dallas, IA

Built 1917 Load: 30.7 t ADT: 20

FM

Fair

Over: IOWA RIVER

088201205, Hardin, IA

Built 1982 Load: 30.7 t ADT: 47

SW 360TH ST

Fair

Over: N BR CREEK

079080803, Johnson, IA

Built 1965 Load: 30.7 t ADT: 61

ROHRET RD

Fair

Over: N FORK OLD MANS CREEK

079082601, Johnson, IA

Built 1978 Load: 30.7 t ADT: 30

NW 120TH ST

Fair

Over: STREAM

081080801, Johnson, IA

Built 1966 Load: 30.7 t ADT: 1,250

IA 21

Fair

Over: SUGAR CREEK

3.0 MI. N OF IA 149, Keokuk, IA

Built 1989 Load: 30.7 t ADT: 630

FM

Fair

Over: STREAM

076112005, Keokuk, IA

Built 1997 Load: 30.7 t ADT: 30

IA 13

Fair

Over: WAPSIPINICON RIVER

IN CENTRAL CITY, Linn, IA

Built 1973 Load: 30.7 t ADT: 5,600

LOCAL

Fair

Over: LONG CREEK

074041407, Louisa, IA

Built 1985 Load: 30.7 t ADT: 123

FM

Fair

Over: LONG CREEK

074042306, Louisa, IA

Built 1987 Load: 30.7 t ADT: 630

FM

Fair

Over: ROCK RIVER

100452003, Lyon, IA

Built 1980 Load: 30.7 t ADT: 180

LOCAL ROAD

Fair

Over: TOM CREEK

100453602, Lyon, IA

Built 1974 Load: 30.7 t ADT: 15

Showing 5,801-5,850 of 20,753 bridges

Related

All states → | National rankings → | Understanding conditions → | SD bridges explained →
Data sourced from the FHWA National Bridge Inventory (NBI), latest released cycle. See our methodology for details. Retrieved and formatted by PlainBridges Editorial.

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). A "structurally deficient" rating is a repair-priority signal, not a closure or unsafe-to-cross designation. Consult a qualified civil engineer before making decisions based on this data.

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.