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

FM

Fair

Over: CEDAR CREEK

076260804, Madison, IA

Built 1984 Load: 30.8 t ADT: 60

FM

Fair

Over: MUD CREEK

085192006, Marshall, IA

Built 1981 Load: 30.8 t ADT: 255

NOBLE AVE

Fair

Over: SPRING CREEK

098162902, Mitchell, IA

Built 1977 Load: 30.8 t ADT: 59

410TH

Fair

Over: BURR OAK CREEK

099163101, Mitchell, IA

Built 1975 Load: 30.8 t ADT: 30

IA 175

Fair

Over: DRAINAGE DITCH

2.9 mi. E of E jct SR L20, Monona, IA

Built 1973 Load: 30.8 t ADT: 1,200

IA 38

Fair

Over: MOSQUITO CREEK

2.2 mi. S of Jct. U.S. 6, Muscatine, IA

Built 1972 Load: 30.8 t ADT: 5,200

FM

Fair

Over: WAPSIE CREEK

078042002, Muscatine, IA

Built 1967 Load: 30.8 t ADT: 60

FREMONT AVE

Fair

Over: FISHER CREEK

068390702, Page, IA

Built 1985 Load: 30.8 t ADT: 41

LOCAL

Fair

Over: DD NO 98

094321901, Palo Alto, IA

Built 1974 Load: 30.8 t ADT: 26

FM

Fair

Over: DD 63

094332702, Palo Alto, IA

Built 1972 Load: 30.8 t ADT: 60

LOCAL

Fair

Over: DD 63

094332802, Palo Alto, IA

Built 1977 Load: 30.8 t ADT: 11

FM

Fair

Over: CREEK

095311401, Palo Alto, IA

Built 1965 Load: 30.8 t ADT: 60

440TH AVE

Fair

Over: STREAM

096332302, Palo Alto, IA

Built 1972 Load: 30.8 t ADT: 82

FM

Fair

Over: DD

096332902, Palo Alto, IA

Built 1976 Load: 30.8 t ADT: 41

LOCAL

Fair

Over: STREAM

096333002, Palo Alto, IA

Built 1972 Load: 30.8 t ADT: 21

FM

Fair

Over: LIZARD CK DD #53

091320504, Pocahontas, IA

Built 1980 Load: 30.8 t ADT: 170

LOCAL

Fair

Over: LIZARD CREEK DD #53

091321501, Pocahontas, IA

Built 1988 Load: 30.8 t ADT: 11

FM

Fair

Over: CROOKED CK DD #60

092310902, Pocahontas, IA

Built 1973 Load: 30.8 t ADT: 60

FM

Fair

Over: CROOKED CK DD #60

092310902, Pocahontas, IA

Built 1973 Load: 30.8 t ADT: 60

LOCAL

Fair

Over: LITTLE CEDAR CREEK

092340601, Pocahontas, IA

Built 1976 Load: 30.8 t ADT: 26

FM SE 6TH AV

Fair

Over: BRANCH DES MOINES RIVER

078220701, Polk, IA

Built 1972 Load: 30.8 t ADT: 678

FM

Fair

Over: STREAM

081131603, Poweshiek, IA

Built 1956 Load: 30.8 t ADT: 30

LOCAL

Fair

Over: RACCOON RIVER

086350404, Sac, IA

Built 1976 Load: 30.8 t ADT: 40

FM

Fair

Over: DD #57

086361201, Sac, IA

Built 1975 Load: 30.8 t ADT: 210

US 59

Fair

Over: DRAINAGE DITCH

2.8 mi. S of Jct. IA 44, Shelby, IA

Built 1966 Load: 30.8 t ADT: 4,940

FM RD F-32

Fair

Over: W FORK W.NISHNABOTNA RIV

080381903, Shelby, IA

Built 1978 Load: 30.8 t ADT: 488

LOCAL

Fair

Over: SMALL STREAM

094440602, Sioux, IA

Built 1965 Load: 30.8 t ADT: 30

FM

Fair

Over: INDIAN CREEK

094473401, Sioux, IA

Built 1984 Load: 30.8 t ADT: 90

LOCAL

Fair

Over: NO NAME CR

097461402, Sioux, IA

Built 1973 Load: 30.8 t ADT: 71

WILLOW AVENUE

Fair

Over: GRAND RIVER

071281110, Union, IA

Built 1980 Load: 30.8 t ADT: 120

LOCAL

Fair

Over: STREAM

072292005, Union, IA

Built 1999 Load: 30.8 t ADT: 46

FM

Fair

Over: BRUSH CREEK

071143004, Wapello, IA

Built 1982 Load: 30.8 t ADT: 110

FM

Fair

Over: BR COMPETINE CREEK

073121303, Wapello, IA

Built 1965 Load: 30.8 t ADT: 130

FM

Fair

Over: BR COMPETINE CREEK

073121403, Wapello, IA

Built 1962 Load: 30.8 t ADT: 130

FM

Fair

Over: WHITE BREAST CREEK

074222705, Warren, IA

Built 1976 Load: 30.8 t ADT: 100

FM

Fair

Over: SOUTH RIVER

076233504, Warren, IA

Built 1979 Load: 30.8 t ADT: 1,330

FM

Fair

Over: DEER CREEK

077233111, Warren, IA

Built 1985 Load: 30.8 t ADT: 937

FM

Fair

Over: NORTH RIVER

077241606, Warren, IA

Built 1986 Load: 30.8 t ADT: 2,998

FM

Fair

Over: RICHLAND CR

074091801, Washington, IA

Built 1972 Load: 30.8 t ADT: 150

LOCAL ROAD

Fair

Over: SMALL STREAM

075092804, Washington, IA

Built 1966 Load: 30.8 t ADT: 60

FM

Fair

Over: WINNEBAGO RIVER

098240103, Winnebago, IA

Built 1968 Load: 30.8 t ADT: 649

LOCAL

Fair

Over: ELLIOT CREEK

088461001, Woodbury, IA

Built 1980 Load: 30.8 t ADT: 34

MILITARY RD

Fair

Over: BIG SIOUX RIVER

000000000, Woodbury, IA

Built 1976 Load: 30.8 t ADT: 7,542

THRUSH

Fair

Over: STREAM

098190802, Worth, IA

Built 1963 Load: 30.8 t ADT: 442

WHEELERWOOD

Fair

Over: DRAINAGE DITCH

098212006, Worth, IA

Built 1960 Load: 30.8 t ADT: 265

VINE

Fair

Over: STREAM

100193402, Worth, IA

Built 1968 Load: 30.8 t ADT: 69

LOCAL

Fair

Over: IOWA RIVER

090231309, Wright, IA

Built 1975 Load: 30.8 t ADT: 46

FM - D AVE

Fair

Over: N PIERSON CREEK

090422702, Cherokee, IA

Built 1961 Load: 30.9 t ADT: 679

FM

Fair

Over: BR NORTH RACCOON RIVER

081290403, Dallas, IA

Built 1915 Load: 30.9 t ADT: 40

EB US 20

Fair

Over: MAQUOKETA RIVER

1.7 mi. E of Jct. IA 13, Delaware, IA

Built 1974 Load: 30.9 t ADT: 3,850

Showing 5,901-5,950 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.