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: BRANCH OF OTTER CREEK

083142302, Tama, IA

Built 1987 Load: 24.3 t ADT: 29

LOCAL

Fair

Over: STREAM

070190102, Appanoose, IA

Built 2000 Load: 24.4 t ADT: 11

HAWTHORNE AV

Fair

Over: BASKINS CR

092132902, Bremer, IA

Built 2000 Load: 24.4 t ADT: 29

HAWTHORNE AV

Fair

Over: BASKINS CR

092133202, Bremer, IA

Built 2001 Load: 24.4 t ADT: 29

HAWTHORNE AV

Fair

Over: BASKINS CR

092133204, Bremer, IA

Built 1995 Load: 24.4 t ADT: 97

FM

Fair

Over: STREAM

093121303, Bremer, IA

Built 1993 Load: 24.4 t ADT: 25

LOCAL

Fair

Over: BEAVER CREEK

096141905, Chickasaw, IA

Built 2004 Load: 24.4 t ADT: 33

LOCAL

Fair

Over: MILLER CREEK

083370301, Crawford, IA

Built 2002 Load: 24.4 t ADT: 11

LOCAL

Fair

Over: HOCKETT CREEK

083382503, Crawford, IA

Built 1991 Load: 24.4 t ADT: 11

FM

Fair

Over: MIDDLE WILLOW CREEK

083412801, Crawford, IA

Built 1954 Load: 24.4 t ADT: 40

120TH STREET

Fair

Over: MIDDLE WILLOW CREEK

083412802, Crawford, IA

Built 2023 Load: 24.4 t ADT: 11

LOCAL

Fair

Over: BUFFALO CREEK

084391601, Crawford, IA

Built 1991 Load: 24.4 t ADT: 15

LOCAL

Fair

Over: BR OF CHARITON RIVER

071211602, Lucas, IA

Built 1955 Load: 24.4 t ADT: 16

US 75

Fair

Over: ROCK RIVER

0.2 mi. N of S Jct SR A34, Lyon, IA

Built 1975 Load: 24.4 t ADT: 2,620

LCL-340TH ST

Fair

Over: STREAM

073411102, Mills, IA

Built 1981 Load: 24.4 t ADT: 20

LOCAL ROAD

Fair

Over: COLDWATER CREEK

100101001, Winneshiek, IA

Built 1970 Load: 24.4 t ADT: 70

UNION AVENUE

Fair

Over: STREAM

071320304, Adams, IA

Built 1974 Load: 24.5 t ADT: 20

200TH STREET

Fair

Over: STREAM

072342501, Adams, IA

Built 1973 Load: 24.5 t ADT: 26

FM-125TH STREET

Fair

Over: STREAM

073341505, Adams, IA

Built 1963 Load: 24.5 t ADT: 159

FM-130TH STREET

Fair

Over: SIN CREEK

073352201, Adams, IA

Built 1980 Load: 24.5 t ADT: 34

FM-CHESTNUT AVE

Fair

Over: SIN CREEK

073351502, Adams, IA

Built 1969 Load: 24.5 t ADT: 190

550TH ST

Fair

Over: BRUSH CREEK

068172201, Appanoose, IA

Built 2022 Load: 24.5 t ADT: 30

170TH AVE

Fair

Over: SHOAL CREEK

068182002, Appanoose, IA

Built 2023 Load: 24.5 t ADT: 51

265TH AVE

Fair

Over: STREAM

069172604, Appanoose, IA

Built 2022 Load: 24.5 t ADT: 11

V66 21 AVE

Fair

Over: COOK CREEK

082113508, Benton, IA

Built 1957 Load: 24.5 t ADT: 1,230

KOBER RD

Fair

Over: TRIB TO WOLF CREEK

87-12-35-02-10, Black Hawk, IA

Built 1969 Load: 24.5 t ADT: 59

JESUP RD

Fair

Over: TRIB TO SPRING CREEK

88-11-23-02-10, Black Hawk, IA

Built 1924 Load: 24.5 t ADT: 393

E DUNKERTON RD

Fair

Over: VIRDEN CREEK

90-12-31-01-10, Black Hawk, IA

Built 1969 Load: 24.5 t ADT: 2,259

FINCHFORD RD

Fair

Over: W FORK CEDAR RVR OVRFLW

90-14-06-06, Black Hawk, IA

Built 1970 Load: 24.5 t ADT: 412

FM

Fair

Over: SMALL

091120302, Bremer, IA

Built 1989 Load: 24.5 t ADT: 687

LOCAL

Fair

Over: RACCOON RIVER

092360801, Buena Vista, IA

Built 1977 Load: 24.5 t ADT: 20

LOCAL

Fair

Over: MAYNES CREEK

091181302, Butler, IA

Built 1993 Load: 24.5 t ADT: 35

FOREST AVE

Fair

Over: SMALL STREAM

092181202, Butler, IA

Built 2011 Load: 24.5 t ADT: 21

LOCAL

Fair

Over: SMALL STREAM

092181401, Butler, IA

Built 1900 Load: 24.5 t ADT: 20

LOCAL - 670TH

Fair

Over: LONE TREE BRANCH

075350502, Cass, IA

Built 1978 Load: 24.5 t ADT: 21

LOCAL - JASPER

Fair

Over: CREEK

076362203, Cass, IA

Built 1984 Load: 24.5 t ADT: 91

LOCAL - 100TH

Fair

Over: CAMP CREEK

077370301, Cass, IA

Built 1964 Load: 24.5 t ADT: 5

LOCAL - CHICAGO

Fair

Over: CREEK

077371401, Cass, IA

Built 1988 Load: 24.5 t ADT: 15

FM- L AVE

Fair

Over: BRANCH LITTLE SIOUX

090410104, Cherokee, IA

Built 1965 Load: 24.5 t ADT: 977

LOCAL- C AVE

Fair

Over: BUFFALO CREEK

090422802, Cherokee, IA

Built 1945 Load: 24.5 t ADT: 26

LOCAL-B AVE.

Fair

Over: STREAM

092420802, Cherokee, IA

Built 1941 Load: 24.5 t ADT: 100

FM BARNES RD

Fair

Over: SMALL

093393004, Cherokee, IA

Built 1979 Load: 24.5 t ADT: 120

LOCAL M AVE

Fair

Over: CREEK

093400702, Cherokee, IA

Built 1970 Load: 24.5 t ADT: 20

450TH ST

Fair

Over: BRANCH BEAR CREEK

093412201, Cherokee, IA

Built 1962 Load: 24.5 t ADT: 330

FM

Fair

Over: BRANCH LONG CREEK

071271401, Clarke, IA

Built 1964 Load: 24.5 t ADT: 60

N.EAST ST.

Fair

Over: CREEK

081030802, Clinton, IA

Built 1960 Load: 24.5 t ADT: 360

390TH ST

Fair

Over: SMALL STREAM

082372502, Crawford, IA

Built 2007 Load: 24.5 t ADT: 35

LOCAL

Fair

Over: SMALL STREAM

082393402, Crawford, IA

Built 2005 Load: 24.5 t ADT: 15

LOCAL

Fair

Over: HOCKETT CREEK

083383601, Crawford, IA

Built 1977 Load: 24.5 t ADT: 30

LOCAL

Fair

Over: BEAR CREEK

083390801, Crawford, IA

Built 1993 Load: 24.5 t ADT: 11

Showing 3,901-3,950 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.