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: VILLAGE CREEK

098042004, Allamakee, IA

Built 1966 Load: 25.9 t ADT: 44

LOCAL

Fair

Over: BR UPPER IOWA RIVER

099063103, Allamakee, IA

Built 1963 Load: 25.9 t ADT: 49

LOCAL

Fair

Over: BR UPPER IA RIVER

099063107, Allamakee, IA

Built 1961 Load: 25.9 t ADT: 15

280TH ST

Fair

Over: BUFFALO CREEK

087070201, Buchanan, IA

Built 2004 Load: 25.9 t ADT: 51

LOCAL

Fair

Over: LITTLE WAPSIPINICON RVR

089100406, Buchanan, IA

Built 1966 Load: 25.9 t ADT: 51

LOCAL

Fair

Over: SMALL STREAM

091173102, Butler, IA

Built 1991 Load: 25.9 t ADT: 39

FM - 730TH ST

Fair

Over: WATERWAY

074340502, Cass, IA

Built 1969 Load: 25.9 t ADT: 79

FM

Fair

Over: SUGAR CREEK

081020303, Cedar, IA

Built 2001 Load: 25.9 t ADT: 40

FM-480TH ST.

Fair

Over: LITTLE SIOUX RIVER

092400101, Cherokee, IA

Built 1965 Load: 25.9 t ADT: 60

LANDAU RD

Fair

Over: LITTLE TURKEY

091023005, Clayton, IA

Built 1955 Load: 25.9 t ADT: 62

WAYMAN RD

Fair

Over: WAYMAN CREEK

091030707, Clayton, IA

Built 1952 Load: 25.9 t ADT: 10

BIG SPRINGS RD

Fair

Over: STREAM

094053007, Clayton, IA

Built 1954 Load: 25.9 t ADT: 47

165TH ST

Fair

Over: DEER CR

094060103, Clayton, IA

Built 1957 Load: 25.9 t ADT: 108

160TH ST

Fair

Over: DEER CREEK

094060203, Clayton, IA

Built 1956 Load: 25.9 t ADT: 51

CHARIOT RD

Fair

Over: STREAM

094062703, Clayton, IA

Built 1954 Load: 25.9 t ADT: 79

CHARIOT RD

Fair

Over: SMALL STREAM

094062611, Clayton, IA

Built 1953 Load: 25.9 t ADT: 49

FM

Fair

Over: CREEK

070143003, Davis, IA

Built 1972 Load: 25.9 t ADT: 70

FM 110 AVE

Fair

Over: S FORK MAQUOKETA RIVER

090061702, Delaware, IA

Built 1969 Load: 25.9 t ADT: 108

FM

Fair

Over: CREEK

089013607, Dubuque, IA

Built 1973 Load: 25.9 t ADT: 59

FM

Fair

Over: CREEK

086203302, Hardin, IA

Built 1921 Load: 25.9 t ADT: 147

305TH ST

Fair

Over: ALLEN CREEK

078441701, Harrison, IA

Built 1974 Load: 25.9 t ADT: 139

FM

Fair

Over: EAST FORK CROOKED CREEK

073051401, Henry, IA

Built 1968 Load: 25.9 t ADT: 70

LOCAL ELM AVE

Fair

Over: STAFF CR

100142602, Howard, IA

Built 1949 Load: 25.9 t ADT: 16

FM

Fair

Over: CREEK

084E11006, Jackson, IA

Built 1988 Load: 25.9 t ADT: 230

FM

Fair

Over: ROCK CREEK

071110610, Jefferson, IA

Built 1964 Load: 25.9 t ADT: 270

COUNTY RD. E-17

Fair

Over: SMALL CREEK

085032301, Jones, IA

Built 1954 Load: 25.9 t ADT: 108

OLD CASS RD.

Fair

Over: SMALL CREEK

085041701, Jones, IA

Built 1900 Load: 25.9 t ADT: 135

LOCAL ROAD

Fair

Over: SMALL STREAM

077130201, Keokuk, IA

Built 1992 Load: 25.9 t ADT: 15

IA 27

Fair

Over: STREAM

2.6 mi. N of Jct. SR J72, Lee, IA

Built 1947 Load: 25.9 t ADT: 7,200

IA 100

Fair

Over: WANATEE CREEK

0.4 MI. W OF JCT. IA 13, Linn, IA

Built 1995 Load: 25.9 t ADT: 14,000

FM

Fair

Over: BR TO WHITEBREAST CREEK

072222903, Lucas, IA

Built 1958 Load: 25.9 t ADT: 90

FM

Fair

Over: EMERY CREEK

099443002, Lyon, IA

Built 1980 Load: 25.9 t ADT: 270

LOCAL

Fair

Over: DRAINAGE

074283001, Madison, IA

Built 1949 Load: 25.9 t ADT: 29

LOCAL

Fair

Over: HOWERDON CREEK

076292602, Madison, IA

Built 1984 Load: 25.9 t ADT: 15

LOCAL

Fair

Over: E BR BUCKLEY CREEK

077170908, Mahaska, IA

Built 1953 Load: 25.9 t ADT: 15

FM

Fair

Over: HENRY CREEK

094392405, O'Brien, IA

Built 1950 Load: 25.9 t ADT: 45

US 59

Fair

Over: DRAINAGE DITCH

1.1 mi N of jct SR A46, Osceola, IA

Built 1976 Load: 25.9 t ADT: 1,070

220TH ST

Fair

Over: DRAINAGE

091440201, Plymouth, IA

Built 1900 Load: 25.9 t ADT: 15

FM

Fair

Over: SO LIZARD CK - DD 22

090322302, Pocahontas, IA

Built 1969 Load: 25.9 t ADT: 180

LOCAL ROAD

Fair

Over: CREEK

081223502, Polk, IA

Built 1900 Load: 25.9 t ADT: 40

FM

Fair

Over: TURKEY CREEK

081251101, Polk, IA

Built 1997 Load: 25.9 t ADT: 159

LOCAL

Fair

Over: STREAM

080153103, Poweshiek, IA

Built 1963 Load: 25.9 t ADT: 26

LOCAL

Fair

Over: SMALL STREAM

079390501, Shelby, IA

Built 1990 Load: 25.9 t ADT: 21

SPRUCE LOOP

Fair

Over: SMALL STREAM

803137, Shelby, IA

Built 2000 Load: 25.9 t ADT: 21

FM

Fair

Over: W BRANCH FLOYD RIVER

094451701, Sioux, IA

Built 1942 Load: 25.9 t ADT: 548

560TH AVE

Fair

Over: WALNUT CREEK

082230602, Story, IA

Built 1915 Load: 25.9 t ADT: 50

LOCAL

Fair

Over: JORDAN CREEK

084152201, Tama, IA

Built 1900 Load: 25.9 t ADT: 39

FM

Fair

Over: BRANCH IOWA RIVER

084152902, Tama, IA

Built 1950 Load: 25.9 t ADT: 39

LOCAL

Fair

Over: NINE MILE CR

070232503, Wayne, IA

Built 1977 Load: 25.9 t ADT: 20

LOCAL

Fair

Over: STREAM

089422003, Woodbury, IA

Built 1980 Load: 25.9 t ADT: 50

Showing 4,401-4,450 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.