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: MIDDLE RIVER

075291006, Madison, IA

Built 1983 Load: 30.5 t ADT: 329

FM

Fair

Over: BIG SLOUGH DRAINAGE DIT.

077040302, Muscatine, IA

Built 1968 Load: 30.5 t ADT: 150

ELMTREE ROAD

Fair

Over: GRAYBILL CREEK

075392901, Pottawattamie, IA

Built 1940 Load: 30.5 t ADT: 20

L14

Fair

Over: FLOYD RIVER

095433004, Sioux, IA

Built 1969 Load: 30.5 t ADT: 578

FM

Fair

Over: FLOYD RIVER

096430103, Sioux, IA

Built 1968 Load: 30.5 t ADT: 679

HWY 20

Fair

Over: DRAINAGE DITCH

088301401, Webster, IA

Built 1984 Load: 30.5 t ADT: 1,482

260TH STREET

Fair

Over: WEST FORK 102 RIVER

071342901, Adams, IA

Built 1970 Load: 30.6 t ADT: 20

LOCAL

Fair

Over: COOPER CREEK

068191202, Appanoose, IA

Built 1972 Load: 30.6 t ADT: 21

LOCAL

Fair

Over: STEIN CREEK

084120801, Benton, IA

Built 1977 Load: 30.6 t ADT: 34

LOCAL

Fair

Over: PRAIRIE CREEK

086103603, Benton, IA

Built 1978 Load: 30.6 t ADT: 88

FM 155TH ST

Fair

Over: PINE CREEK

090083105, Buchanan, IA

Built 1969 Load: 30.6 t ADT: 59

FM

Fair

Over: LIZARD CREEK SO BRANCH

089311202, Calhoun, IA

Built 1969 Load: 30.6 t ADT: 240

FM

Fair

Over: PURGATORY CREEK

085332401, Carroll, IA

Built 1969 Load: 30.6 t ADT: 180

LOCAL - TUCSON

Fair

Over: WEST NODAWAY RIVER

074340701, Cass, IA

Built 1972 Load: 30.6 t ADT: 35

LOCAL - 720TH

Fair

Over: SEVEN MILE CREEK

075340602, Cass, IA

Built 1978 Load: 30.6 t ADT: 30

FM L AVE

Fair

Over: BEAR CREEK

093412402, Cherokee, IA

Built 1979 Load: 30.6 t ADT: 219

FM

Fair

Over: STREAM

094140301, Chickasaw, IA

Built 1981 Load: 30.6 t ADT: 29

LOCAL

Fair

Over: WHITE BREAST CREEK

072253006, Clarke, IA

Built 1969 Load: 30.6 t ADT: 50

340TH ST

Fair

Over: BIG MEADOW CREEK

096361001, Clay, IA

Built 1981 Load: 30.6 t ADT: 105

230TH AVE

Fair

Over: DD #28

097362902, Clay, IA

Built 1979 Load: 30.6 t ADT: 123

GREAT RIVER RD

Fair

Over: PANTHER CR

091012604, Clayton, IA

Built 1968 Load: 30.6 t ADT: 344

FM

Fair

Over: GRIFFIN CREEK

082391701, Crawford, IA

Built 1962 Load: 30.6 t ADT: 349

FM

Fair

Over: BUCK CREEK

082391701, Crawford, IA

Built 1962 Load: 30.6 t ADT: 349

NATURE RD

Fair

Over: SMALL STREAM

090040904, Delaware, IA

Built 1940 Load: 30.6 t ADT: 26

LOCAL

Fair

Over: FLINT RIVER

071042107, Des Moines, IA

Built 1972 Load: 30.6 t ADT: 21

LOCAL

Fair

Over: CREEK

098352901, Dickinson, IA

Built 1974 Load: 30.6 t ADT: 26

FM

Fair

Over: LITTLE SIOUX RIVER

100371502, Dickinson, IA

Built 1970 Load: 30.6 t ADT: 51

LOCAL

Fair

Over: ACKLEY CREEK

094182402, Floyd, IA

Built 1979 Load: 30.6 t ADT: 26

FM

Fair

Over: GIZZARD CREEK

095153601, Floyd, IA

Built 1970 Load: 30.6 t ADT: 108

FM OLIVE AVE

Fair

Over: BEEDS CREEK

092202806, Franklin, IA

Built 1961 Load: 30.6 t ADT: 1,365

NETTLE AVE

Fair

Over: OTTER CREEK

093203202, Franklin, IA

Built 1978 Load: 30.6 t ADT: 20

FM

Fair

Over: MASON CREEK

079322603, Guthrie, IA

Built 1978 Load: 30.6 t ADT: 50

LOCAL

Fair

Over: COTTONWOOD CREEK

080301802, Guthrie, IA

Built 1974 Load: 30.6 t ADT: 89

FM

Fair

Over: BRUSHY CREEK

081333503, Guthrie, IA

Built 1979 Load: 30.6 t ADT: 60

FM

Fair

Over: SUGAR CREEK

073073004, Henry, IA

Built 1968 Load: 30.6 t ADT: 110

LOCAL

Fair

Over: BRUSH CREEK

085E30103, Jackson, IA

Built 1985 Load: 30.6 t ADT: 79

LOCAL

Fair

Over: CHERRY CREEK

080192910, Jasper, IA

Built 1971 Load: 30.6 t ADT: 527

FM

Fair

Over: PRAIRIE CREEK

080201403, Jasper, IA

Built 1971 Load: 30.6 t ADT: 630

WHITE OAK RD.

Fair

Over: SOUTH FORK WALNUT CREEK

083041608, Jones, IA

Built 1970 Load: 30.6 t ADT: 49

IA 21

Fair

Over: CEDAR CREEK

1.1 mi. N of jct. IA 92, Keokuk, IA

Built 1948 Load: 30.6 t ADT: 1,880

LOC 10TH AVE

Fair

Over: BLACK CAT CREEK

098303002, Kossuth, IA

Built 1978 Load: 30.6 t ADT: 26

LOCAL

Fair

Over: MUSCATINE SLOUGH

075023104, Louisa, IA

Built 1968 Load: 30.6 t ADT: 650

FM

Fair

Over: OVERFLOW

098433402, Lyon, IA

Built 1968 Load: 30.6 t ADT: 199

LOCAL ROAD

Fair

Over: TOM CREEK

100442402, Lyon, IA

Built 1969 Load: 30.6 t ADT: 15

FM

Fair

Over: N. FORK CLANTON CREEK

074270703, Madison, IA

Built 1986 Load: 30.6 t ADT: 40

FM

Fair

Over: MIDDLE CREEK

077163503, Mahaska, IA

Built 1971 Load: 30.6 t ADT: 60

IA 330

Fair

Over: LINN CREEK

1.8 MILES N OF JCT. US 30, Marshall, IA

Built 1964 Load: 30.6 t ADT: 2,390

FM-195TH ST

Fair

Over: STREAM

071432102, Mills, IA

Built 1970 Load: 30.6 t ADT: 110

FA-CARY AVE

Fair

Over: SILVER CREEK

073421301, Mills, IA

Built 1975 Load: 30.6 t ADT: 229

FM

Fair

Over: MUD CREEK

094411701, O'Brien, IA

Built 1968 Load: 30.6 t ADT: 71

Showing 5,751-5,800 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.