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

LOCAL

Poor

Over: CREEK

070111406, Van Buren, IA

Built 1968 Load: 9.1 t ADT: 11

LOCAL ROAD

Poor

Over: SMALL STREAM

077060804, Washington, IA

Built 1966 Load: 9.1 t ADT: 80

LOCAL

Poor

Over: DRAINAGE DITCH

099240301, Winnebago, IA

Built 1976 Load: 9.1 t ADT: 72

LOCAL

Poor

Over: STREAM

0874307, Woodbury, IA

Built 1920 Load: 9.1 t ADT: 60

LOCAL

Poor

Over: EAST FORK CROOKED CREEK

073051104, Henry, IA

Built 1914 Load: 9.2 t ADT: 16

210TH STREET

Poor

Over: WEST PLATTE RIVER

072323503, Adams, IA

Built 1966 Load: 9.3 t ADT: 11

LOCAL

Poor

Over: MIDDLE RACCOON RIVER

083343503, Carroll, IA

Built 1914 Load: 9.3 t ADT: 15

LOCAL

Poor

Over: BURR OAK CR

069122102, Davis, IA

Built 1964 Load: 9.3 t ADT: 26

LOCAL

Poor

Over: MIDDLE RIVER

078332302, Guthrie, IA

Built 1981 Load: 9.3 t ADT: 40

FM

Poor

Over: BUCKLEY CREEK

077170901, Mahaska, IA

Built 1951 Load: 9.3 t ADT: 70

LOCAL

Poor

Over: DD 80

095321203, Palo Alto, IA

Built 1959 Load: 9.3 t ADT: 50

FM

Poor

Over: SOUTH ENGLISH RIVER

078142002, Poweshiek, IA

Built 1990 Load: 9.3 t ADT: 30

LOCAL

Poor

Over: N ENGLISH RIVER

079160102, Poweshiek, IA

Built 1924 Load: 9.3 t ADT: 15

FM

Poor

Over: CHARITON RIVER

069210504, Wayne, IA

Built 1958 Load: 9.3 t ADT: 90

COLDWATER CREEK RD

Poor

Over: CREEK

100093205, Winneshiek, IA

Built 1978 Load: 9.3 t ADT: 59

LOCAL/KEYSTONE

Poor

Over: TURKEY CREEK

076362701, Cass, IA

Built 1900 Load: 9.4 t ADT: 35

LOC 128 TRAIL

Poor

Over: BOYER RIVER

081411705, Harrison, IA

Built 1940 Load: 9.4 t ADT: 89

LOCAL

Poor

Over: REEDS CREEK

068081103, Van Buren, IA

Built 1967 Load: 9.4 t ADT: 35

FM

Poor

Over: SM STREAM

090382101, Buena Vista, IA

Built 1974 Load: 9.5 t ADT: 569

DOGWOOD AVE

Poor

Over: DRAINAGE

092482602, Plymouth, IA

Built 1970 Load: 9.5 t ADT: 15

LOCAL

Poor

Over: LITTLE ROCK RIVER

100423001, Osceola, IA

Built 1941 Load: 9.6 t ADT: 15

LOCAL

Poor

Over: N LIZARD CREEK

092322302, Pocahontas, IA

Built 1914 Load: 9.6 t ADT: 11

A AVE

Poor

Over: STREAM

092060604, Clayton, IA

Built 1900 Load: 9.7 t ADT: 11

LOCAL

Poor

Over: STREAM

066052403, Lee, IA

Built 1900 Load: 9.7 t ADT: 11

FM

Poor

Over: TARKIO CREEK

071370405, Montgomery, IA

Built 1949 Load: 9.7 t ADT: 159

FM

Poor

Over: BRANCH WOLF CREEK

085130602, Tama, IA

Built 1916 Load: 9.7 t ADT: 34

MIDDLE ROAD

Poor

Over: SPRING CREEK

APPROX. 7000' E. OF RD. H, Des Moines, IA

Built 1910 Load: 9.8 t ADT: 5

FM

Poor

Over: SMALL STREAM

081333101, Guthrie, IA

Built 1984 Load: 9.8 t ADT: 26

LCL-INGRAHAM AV

Poor

Over: STREAM

072401501, Mills, IA

Built 1954 Load: 9.8 t ADT: 5

LOCAL

Poor

Over: SMALL STREAM

073362601, Montgomery, IA

Built 1985 Load: 9.8 t ADT: 5

LOCAL

Poor

Over: LITTLE BEAVER CREEK

080253504, Polk, IA

Built 1926 Load: 9.8 t ADT: 199

LOCAL

Poor

Over: STREAM

070300703, Ringgold, IA

Built 1940 Load: 9.8 t ADT: 29

FM

Poor

Over: CREEK

079343003, Audubon, IA

Built 1956 Load: 9.9 t ADT: 34

LOCAL- 600TH ST

Poor

Over: ROCK CREEK

090410401, Cherokee, IA

Built 1900 Load: 9.9 t ADT: 20

LOCAL

Poor

Over: BOYER RIVER

084380504, Crawford, IA

Built 1971 Load: 9.9 t ADT: 30

LOCAL

Poor

Over: COAL CREEK

074170107, Mahaska, IA

Built 1900 Load: 9.9 t ADT: 71

LOCAL

Poor

Over: SMALL STREAM

084413201, Crawford, IA

Built 1965 Load: 10.0 t ADT: 21

LOCAL

Poor

Over: INDIAN CREEK

081212706, Jasper, IA

Built 1918 Load: 10.0 t ADT: 35

IRVINGTON RD

Poor

Over: D D # 51

095291303, Kossuth, IA

Built 1966 Load: 10.0 t ADT: 330

LOCAL

Poor

Over: DOWD CREEK

085190104, Marshall, IA

Built 1916 Load: 10.0 t ADT: 39

LCL-ELDERBERRY

Poor

Over: MUD CREEK

073412505, Mills, IA

Built 1960 Load: 10.0 t ADT: 60

270TH ST

Poor

Over: DRAINAGE DITCH 2

083213501, Story, IA

Built 1951 Load: 10.0 t ADT: 20

FM

Poor

Over: DEER CREEK

077081001, Washington, IA

Built 1953 Load: 10.0 t ADT: 50

LOCAL ROAD

Poor

Over: CREEK

099101301, Winneshiek, IA

Built 1900 Load: 10.0 t ADT: 26

JONQUIL

Poor

Over: ELK CREEK

099212202, Worth, IA

Built 1957 Load: 10.0 t ADT: 21

LOCAL

Poor

Over: WELDON RIVER

070251204, Decatur, IA

Built 1955 Load: 10.1 t ADT: 35

FM

Poor

Over: DEER CREEK

080231812, Polk, IA

Built 1950 Load: 10.1 t ADT: 2,421

230TH ST

Poor

Over: CREEK

091260703, Wright, IA

Built 1900 Load: 10.1 t ADT: 46

LOCAL

Poor

Over: LONG CREEK

070261605, Decatur, IA

Built 1930 Load: 10.2 t ADT: 21

FM

Poor

Over: ENGLISH RIVER

077111904, Keokuk, IA

Built 1960 Load: 10.2 t ADT: 20

Showing 16,801-16,850 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.