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: E CEDAR CREEK

087313201, Calhoun, IA

Built 1956 Load: 18.5 t ADT: 11

LOCAL

Fair

Over: OTTER CREEK

079023603, Cedar, IA

Built 1993 Load: 18.5 t ADT: 20

390TH ST

Fair

Over: MAQUOKETA RIVER

091063103, Clayton, IA

Built 1958 Load: 18.5 t ADT: 108

KENNEDY RD

Fair

Over: SM STREAM

092030807, Clayton, IA

Built 1955 Load: 18.5 t ADT: 34

GRAPE RD

Fair

Over: DRY MILL CR

093043003, Clayton, IA

Built 1959 Load: 18.5 t ADT: 69

LOCAL

Fair

Over: CREEK

090E13505, Dubuque, IA

Built 1973 Load: 18.5 t ADT: 80

FM

Fair

Over: BEAR CREEK

086190907, Hardin, IA

Built 1900 Load: 18.5 t ADT: 59

60TH AVE.

Fair

Over: MINERAL CREEK

085012904, Jones, IA

Built 1976 Load: 18.5 t ADT: 35

FM

Fair

Over: BLUFF CREEK

074162106, Mahaska, IA

Built 1957 Load: 18.5 t ADT: 110

LOCAL

Fair

Over: ENGLISH CREEK

074203006, Marion, IA

Built 1958 Load: 18.5 t ADT: 62

LOCAL

Fair

Over: DRAINAGE

072183503, Monroe, IA

Built 1940 Load: 18.5 t ADT: 15

LOCAL RD

Fair

Over: WHITES CREEK

073181603, Monroe, IA

Built 1972 Load: 18.5 t ADT: 100

FM

Fair

Over: WHISKEY CREEK

094413202, O'Brien, IA

Built 1927 Load: 18.5 t ADT: 34

FM

Fair

Over: ELKHORN CREEK

078372007, Shelby, IA

Built 1959 Load: 18.5 t ADT: 29

350TH ST

Fair

Over: SMALL STREAM

096441704, Sioux, IA

Built 1938 Load: 18.5 t ADT: 11

LOCAL

Fair

Over: CREEK

068353102, Taylor, IA

Built 1956 Load: 18.5 t ADT: 20

FM

Fair

Over: CALEB CREEK

067230606, Wayne, IA

Built 1952 Load: 18.5 t ADT: 25

FM

Fair

Over: NORTH CHARITON

070230801, Wayne, IA

Built 1957 Load: 18.5 t ADT: 110

FM

Fair

Over: UPPER IOWA RIVER

100103502, Winneshiek, IA

Built 1952 Load: 18.5 t ADT: 69

IVORY AVE

Fair

Over: BASKINS CREEK

091132802, Bremer, IA

Built 2003 Load: 18.6 t ADT: 78

LOCAL 430TH ST

Fair

Over: CREEK

093410701, Cherokee, IA

Built 1926 Load: 18.6 t ADT: 5

LOCAL

Fair

Over: STREAM

068131804, Davis, IA

Built 1945 Load: 18.6 t ADT: 26

250 TH

Fair

Over: BUTTRICKS CREEK

083302401, Greene, IA

Built 1957 Load: 18.6 t ADT: 45

LOCAL

Fair

Over: WHITE FOX CR

089251503, Hamilton, IA

Built 1955 Load: 18.6 t ADT: 40

PARK LANE

Fair

Over: DRY RUN CREEK

CITY CULVERT NO. 36C, Black Hawk, IA

Built 1968 Load: 18.7 t ADT: 3,587

250TH ST

Fair

Over: BASKINS CREEK

091132003, Bremer, IA

Built 1955 Load: 18.7 t ADT: 462

305 TH / E57

Fair

Over: RACCOON RIVER

082291805, Greene, IA

Built 1940 Load: 18.7 t ADT: 170

205TH ST

Fair

Over: DRAINAGE DITCH

088182903, Grundy, IA

Built 1955 Load: 18.7 t ADT: 491

LOCAL

Fair

Over: CREEK

086190201, Hardin, IA

Built 1990 Load: 18.7 t ADT: 20

KENTUCKY AVE

Fair

Over: SMALL

073061102, Henry, IA

Built 2005 Load: 18.7 t ADT: 11

FM

Fair

Over: SOUTH OTTER CREEK

073233401, Lucas, IA

Built 1956 Load: 18.7 t ADT: 45

FM

Fair

Over: N SKUNK RIVER

082201009, Marshall, IA

Built 1956 Load: 18.7 t ADT: 413

LOCAL

Fair

Over: DRAINAGE (CREEK)

071172503, Monroe, IA

Built 1960 Load: 18.7 t ADT: 30

LOCAL

Fair

Over: MILLER CREEK

073163103, Monroe, IA

Built 2000 Load: 18.7 t ADT: 20

LOCAL

Fair

Over: STREAM

071192401, Monroe, IA

Built 1987 Load: 18.7 t ADT: 11

FM

Fair

Over: BRANCH FOUR MILE CREEK

081241001, Polk, IA

Built 1975 Load: 18.7 t ADT: 259

IA 92

Fair

Over: WEST NISHNABOTNA RIVER

0.1 Mi. W of Carson, Pottawattamie, IA

Built 1929 Load: 18.7 t ADT: 2,320

6TH AVE

Fair

Over: INDIAN CREEK

000000000, Pottawattamie, IA

Built 1930 Load: 18.7 t ADT: 217

FM

Fair

Over: BIG BEAR CREEK

080150502, Poweshiek, IA

Built 1955 Load: 18.7 t ADT: 45

FM

Fair

Over: WALNUT CREEK

081152402, Poweshiek, IA

Built 1991 Load: 18.7 t ADT: 10

210TH AVE

Fair

Over: WEST FORK GRAND RIVER

070300102, Ringgold, IA

Built 1957 Load: 18.7 t ADT: 67

LOCAL

Fair

Over: SALT CREEK

084141202, Tama, IA

Built 1985 Load: 18.7 t ADT: 39

LOCAL

Fair

Over: CREEK

069330703, Taylor, IA

Built 1973 Load: 18.7 t ADT: 26

LOCAL

Fair

Over: NODAWAY RIVER DITCH

070350901, Taylor, IA

Built 1966 Load: 18.7 t ADT: 11

FM

Fair

Over: STREAM

097071506, Winneshiek, IA

Built 1959 Load: 18.7 t ADT: 1,375

FM-240TH STREET

Fair

Over: EAST NODAWAY RIVER

071340735, Adams, IA

Built 1978 Load: 18.8 t ADT: 79

200TH STREET

Fair

Over: WEST PLATTE RIVER

072322601, Adams, IA

Built 1979 Load: 18.8 t ADT: 20

LOCAL

Fair

Over: VILLAGE CREEK

098052204, Allamakee, IA

Built 1974 Load: 18.8 t ADT: 39

CARTER AVE

Fair

Over: SMALL STREAM

087102904, Buchanan, IA

Built 1952 Load: 18.8 t ADT: 62

INDIANA AVE

Fair

Over: OTTER CR

090092804, Buchanan, IA

Built 2010 Load: 18.8 t ADT: 62

Showing 2,251-2,300 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.