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

KITTYHAWK AVE

Good

Over: FIELD STREAM

083350202, Carroll, IA

Built 2005 Load: 21.6 t ADT: 50

MISSOURI TAYLOR ST

Good

Over: PLATTE RIVER DITCH

067322843, Taylor, IA

Built 1978 Load: 21.6 t ADT: 60

50TH ST.

Good

Over: OTTER CREEK

091091801, Fayette, IA

Built 2008 Load: 21.7 t ADT: 59

LOCAL

Good

Over: PRICE CREEK

081100302, Iowa, IA

Built 1981 Load: 21.7 t ADT: 80

IA 3 & 12

Good

Over: DRAINAGE DITCH

At E jct of Iowa 12, Plymouth, IA

Built 1976 Load: 21.7 t ADT: 2,340

JUNIPER AVE

Good

Over: DRAINAGE

091461404, Plymouth, IA

Built 1990 Load: 21.7 t ADT: 5

500TH ST

Good

Over: SILVER CREEK

500th West of Hazel, Shelby, IA

Built 2017 Load: 21.7 t ADT: 15

LEVEE

Good

Over: LAKE ODESSA INLET

SEC 5 T74N R2W, Louisa, IA

Built 1996 Load: 21.8 t ADT: 100

US 218

Good

Over: STREAM

1.0 mile North of SR A19, Mitchell, IA

Built 1967 Load: 21.8 t ADT: 2,530

330TH

Good

Over: FISH CREEK

097161201, Mitchell, IA

Built 1974 Load: 21.8 t ADT: 11

PARTRIDGE AVE

Good

Over: STREAM

North of 370th Street, Worth, IA

Built 1978 Load: 21.8 t ADT: 166

390TH ST

Good

Over: FLEMMING CREEK

084370102, Crawford, IA

Built 2016 Load: 21.9 t ADT: 30

LOCAL

Good

Over: ASHTON CREEK

089411101, Ida, IA

Built 2009 Load: 21.9 t ADT: 15

LOCAL

Good

Over: SMALL CREEK

075072204, Washington, IA

Built 1977 Load: 21.9 t ADT: 200

CHIMNEY ROCK RD

Good

Over: UPPER IOWA RIVER

0.5 MI W of W20, Winneshiek, IA

Built 2020 Load: 21.9 t ADT: 26

LOCAL

Good

Over: STREAM

077313002, Adair, IA

Built 2006 Load: 22.0 t ADT: 35

LOC 225 ST

Good

Over: SMALL STREAM

088040306, Delaware, IA

Built 1996 Load: 22.0 t ADT: 39

LOCAL

Good

Over: N CEDAR CREEK

074181604, Marion, IA

Built 1997 Load: 22.0 t

FM

Good

Over: DRY RUN

095400605, O'Brien, IA

Built 1998 Load: 22.0 t ADT: 1,168

GRAND AVE

Good

Over: DRAINAGE

Grand Ave, Polk, IA

Built 2017 Load: 22.0 t ADT: 95

LOCAL

Good

Over: FOUR MILE CREEK

086153303, Tama, IA

Built 2001 Load: 22.0 t ADT: 11

WESTBROOK RD

Good

Over: TRIB TO BEAVER CREEK

89-14-06-01-10, Black Hawk, IA

Built 1984 Load: 22.1 t ADT: 44

J AVE

Good

Over: MIDDLE SOLDIER RIVER

084412001, Crawford, IA

Built 2018 Load: 22.1 t ADT: 21

FM

Good

Over: ZADIE CREEK

067272203, Decatur, IA

Built 2003 Load: 22.1 t ADT: 71

760 140TH ST

Good

Over: BRANCH BOONE RVR DD 159

094251701, Hancock, IA

Built 1985 Load: 22.1 t ADT: 15

LOC 140TH ST

Good

Over: HINE CREEK

094291801, Kossuth, IA

Built 1983 Load: 22.1 t ADT: 15

LOC 110TH ST

Good

Over: TRULNER CREEK

094303401, Kossuth, IA

Built 1981 Load: 22.1 t ADT: 41

LOC 420TH ST

Good

Over: DRAINAGE DITCH #90

099273001, Kossuth, IA

Built 1983 Load: 22.1 t ADT: 62

BENTON AVE

Good

Over: MUD CREEK

070073208, Henry, IA

Built 2005 Load: 22.2 t ADT: 11

MULBERRY AVE

Good

Over: W BRANCH 102 RIVER

071332904, Adams, IA

Built 1980 Load: 22.3 t ADT: 26

FM

Good

Over: BEAVER CREEK

090181702, Butler, IA

Built 1980 Load: 22.3 t ADT: 59

FLOYD LINE ST

Good

Over: STREAM

093150401, Butler, IA

Built 1971 Load: 22.3 t ADT: 10

FOREST AVE

Good

Over: COLDWATER CREEK

Forest Ave. N. of 110th, Butler, IA

Built 2017 Load: 22.3 t ADT: 26

FM

Good

Over: W FK W NISHNABOTNA RVR

082383506, Crawford, IA

Built 1969 Load: 22.3 t ADT: 120

LOCAL

Good

Over: EAST SOLDIER RIVER

084401102, Crawford, IA

Built 1977 Load: 22.3 t ADT: 21

FM

Good

Over: CREEK

078292503, Dallas, IA

Built 1966 Load: 22.3 t ADT: 270

120 TH

Good

Over: BUTTRICKS CREEK

085291601, Greene, IA

Built 1979 Load: 22.3 t ADT: 15

LOCAL

Good

Over: EAST BR BOONE RIVER

094263602, Hancock, IA

Built 1983 Load: 22.3 t ADT: 50

LOCAL

Good

Over: ALDRICH CREEK

087411701, Ida, IA

Built 2006 Load: 22.3 t ADT: 26

FM

Good

Over: ENGLISH RIVER

078102704, Iowa, IA

Built 1971 Load: 22.3 t ADT: 490

LOC 60TH AVE

Good

Over: BLACK CAT CREEK

097302502, Kossuth, IA

Built 1984 Load: 22.3 t ADT: 11

LOCAL

Good

Over: BUCK CR

077151607, Mahaska, IA

Built 1975 Load: 22.3 t ADT: 30

LOCAL

Good

Over: LITTLE BEAR CREEK

080132104, Poweshiek, IA

Built 1985 Load: 22.3 t ADT: 20

FM

Good

Over: STREAM

070351002, Taylor, IA

Built 1981 Load: 22.3 t ADT: 34

LOCAL

Good

Over: EAGLE CREEK

090251801, Wright, IA

Built 1981 Load: 22.3 t ADT: 35

W AVE

Good

Over: SMALL STREAM

082372801, Crawford, IA

Built 2019 Load: 22.4 t ADT: 15

U AVE

Good

Over: HICKEY CREEK

082381301, Crawford, IA

Built 2011 Load: 22.4 t ADT: 41

35TH ST.

Good

Over: WALNUT CREEK

083031903, Jones, IA

Built 1980 Load: 22.4 t ADT: 88

IA 60

Good

Over: WOLF CREEK

1.5 mi. N of jct. US 75, Plymouth, IA

Built 2004 Load: 22.4 t ADT: 6,200

LOCAL

Good

Over: STREAM

068311303, Ringgold, IA

Built 1996 Load: 22.4 t ADT: 11

Showing 9,301-9,350 of 20,753 bridges

Related

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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.