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

Fair

Over: CREEK

089020601, Dubuque, IA

Built 2002 Load: 23.7 t ADT: 79

LOCAL

Fair

Over: BLACK CAT CREEK

098312601, Emmet, IA

Built 1978 Load: 23.7 t ADT: 20

LOCAL

Fair

Over: JACK CREEK

099322903, Emmet, IA

Built 1970 Load: 23.7 t ADT: 45

LOCAL

Fair

Over: STREAM

078323303, Guthrie, IA

Built 1979 Load: 23.7 t ADT: 5

LOCAL

Fair

Over: WOLF CREEK

078330301, Guthrie, IA

Built 1981 Load: 23.7 t ADT: 45

160 280TH ST

Fair

Over: PLUM CREEK

096260601, Hancock, IA

Built 1977 Load: 23.7 t ADT: 11

S 88TH AVE W

Fair

Over: CALHOUN CREEK

078211201, Jasper, IA

Built 1950 Load: 23.7 t ADT: 47

FM MAHAFFY BR R

Fair

Over: STREAM

081062806, Johnson, IA

Built 2000 Load: 23.7 t ADT: 3,730

42ND ST.

Fair

Over: S FORK WALNUT CREEK

083041805, Jones, IA

Built 1994 Load: 23.7 t ADT: 59

FREMONT RD.

Fair

Over: HELMER CREEK

085041702, Jones, IA

Built 1984 Load: 23.7 t ADT: 69

RIVERVIEW RD.

Fair

Over: FARM CREEK

086011806, Jones, IA

Built 1978 Load: 23.7 t ADT: 82

CLUB RD

Fair

Over: SOUTH HOOSIER CREEK

082072706, Linn, IA

Built 1979 Load: 23.7 t ADT: 913

LOCAL

Fair

Over: FLOYD RIVER

097410702, O'Brien, IA

Built 1939 Load: 23.7 t ADT: 26

FM

Fair

Over: DRY RUN

100402602, Osceola, IA

Built 1996 Load: 23.7 t ADT: 459

LOCAL

Fair

Over: STREAM

094343601, Palo Alto, IA

Built 1932 Load: 23.7 t ADT: 21

LOCAL

Fair

Over: PILOT CREEK

092310304, Pocahontas, IA

Built 1961 Load: 23.7 t ADT: 60

FM

Fair

Over: STREAM

070300401, Ringgold, IA

Built 1976 Load: 23.7 t ADT: 120

300TH ST

Fair

Over: CREEK

080E41401, Scott, IA

Built 1970 Load: 23.7 t ADT: 1,470

FM

Fair

Over: ELK CREEK

081370701, Shelby, IA

Built 1949 Load: 23.7 t ADT: 29

335TH ST

Fair

Over: WOLF CREEK

082213303, Story, IA

Built 1967 Load: 23.7 t ADT: 80

FM

Fair

Over: STREAM

070101704, Van Buren, IA

Built 1976 Load: 23.7 t ADT: 40

FM

Fair

Over: STREAM

090261001, Wright, IA

Built 1978 Load: 23.7 t ADT: 100

LOCAL

Fair

Over: BIG CREEK

083251901, Boone, IA

Built 1920 Load: 23.8 t ADT: 71

ADAMS AVE

Fair

Over: STREAM

079043020, Cedar, IA

Built 1923 Load: 23.8 t ADT: 60

LOCAL

Fair

Over: BR LIZARD CREEK

081012303, Cedar, IA

Built 1997 Load: 23.8 t ADT: 26

110TH ST

Fair

Over: SIBLES CREEK

082031201, Cedar, IA

Built 1945 Load: 23.8 t ADT: 50

LOCAL

Fair

Over: SMALL

095121802, Chickasaw, IA

Built 1988 Load: 23.8 t ADT: 27

IA 141

Fair

Over: EAST SOLDIER RIVER

0.1 mi. W of SR L51, Crawford, IA

Built 1953 Load: 23.8 t ADT: 1,490

FM

Fair

Over: E FORK DES MOINES RIVER

099310604, Emmet, IA

Built 1959 Load: 23.8 t ADT: 20

LOCAL

Fair

Over: E FORK DES MOINES RIVER

099310801, Emmet, IA

Built 1962 Load: 23.8 t ADT: 34

LOCAL

Fair

Over: E FORK DES MOINES R

099312101, Emmet, IA

Built 1975 Load: 23.8 t ADT: 30

LOCAL

Fair

Over: E FORK DES MOINES RIVER

099312503, Emmet, IA

Built 1970 Load: 23.8 t ADT: 15

LOCAL

Fair

Over: E FORK DES MOINES RIVER

100323501, Emmet, IA

Built 1962 Load: 23.8 t ADT: 26

LOCAL

Fair

Over: OTTER CREEK

100412002, Osceola, IA

Built 1955 Load: 23.8 t ADT: 46

200TH ST

Fair

Over: BIG WHISKEY SLOUGH

092432601, Plymouth, IA

Built 1987 Load: 23.8 t ADT: 15

FM

Fair

Over: SALT CREEK

084130301, Tama, IA

Built 1985 Load: 23.8 t ADT: 20

US 63 SB

Fair

Over: STREAM

1.2 MI. S OF JCT IA #137, Wapello, IA

Built 1997 Load: 23.8 t ADT: 4,950

LOCAL ROAD

Fair

Over: CREEK

097102904, Winneshiek, IA

Built 1900 Load: 23.8 t ADT: 20

LOCAL

Fair

Over: GRAND RIVER

076303102, Adair, IA

Built 1958 Load: 23.9 t ADT: 15

HOFF RD

Fair

Over: PRESCOTTS CREEK

88-13-17-04-10, Black Hawk, IA

Built 1900 Load: 23.9 t ADT: 29

250TH ST

Fair

Over: CRANE CREEK OVERFLOW

091122101, Bremer, IA

Built 2016 Load: 23.9 t ADT: 49

LOCAL

Fair

Over: SMALL STREAM

091160801, Butler, IA

Built 1988 Load: 23.9 t ADT: 31

LOCAL

Fair

Over: OTTER CR

079011902, Cedar, IA

Built 1975 Load: 23.9 t ADT: 26

LOCAL- 640TH ST

Fair

Over: SILVER CREEK

090402701, Cherokee, IA

Built 1982 Load: 23.9 t ADT: 26

LOCAL-620TH ST

Fair

Over: SMALL CREEK

090421301, Cherokee, IA

Built 1932 Load: 23.9 t ADT: 15

T AVE

Fair

Over: VOLGA RIVER

093101302, Fayette, IA

Built 1928 Load: 23.9 t ADT: 70

KOALA AVE

Fair

Over: TRIB TO MIDDLE RIVER

078321602, Guthrie, IA

Built 2009 Load: 23.9 t ADT: 50

FM

Fair

Over: SMALL STREAM

081323301, Guthrie, IA

Built 1986 Load: 23.9 t ADT: 29

IA 78

Fair

Over: CROOKED CREEK

0.2 MI. E OF S.R. W-47, Henry, IA

Built 1951 Load: 23.9 t ADT: 1,170

195TH ST

Fair

Over: BOHEMIAN CREEK

097111103, Howard, IA

Built 1989 Load: 23.9 t ADT: 16

Showing 3,751-3,800 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.