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

W60 OLD STAGE RD

Fair

Over: BRANCH YELLOW RIVER

097063502, Allamakee, IA

Built 1959 Load: 17.0 t ADT: 422

LOCAL RD

Fair

Over: TROUT RUN

098041603, Allamakee, IA

Built 1965 Load: 17.0 t ADT: 29

FM

Fair

Over: BR VILLAGE CREEK

098042006, Allamakee, IA

Built 1961 Load: 17.0 t ADT: 44

LOCAL

Fair

Over: BRANCH VILLAGE CREEK

098042203, Allamakee, IA

Built 1940 Load: 17.0 t ADT: 108

LOCAL

Fair

Over: BR VILLAGE CREEK

098052603, Allamakee, IA

Built 1962 Load: 17.0 t ADT: 49

FM

Fair

Over: BR UPPER IOWA RIVER

099050503, Allamakee, IA

Built 1952 Load: 17.0 t ADT: 196

LOCAL

Fair

Over: BR UPPER IOWA RIVER

100043303, Allamakee, IA

Built 1937 Load: 17.0 t ADT: 15

FM

Fair

Over: BRANCH UPPER IOWA RIVER

100053603, Allamakee, IA

Built 1930 Load: 17.0 t ADT: 648

LOCAL

Fair

Over: CREEK

081350103, Audubon, IA

Built 1939 Load: 17.0 t ADT: 11

1ST ST W

Fair

Over: WAPSIPINICON RIVER

T89N-R9W-S34-N0.0-E85.2, Buchanan, IA

Built 1917 Load: 17.0 t ADT: 10,258

165TH ST

Fair

Over: SMALL CREEK

10W89N036050, Buchanan, IA

Built 1900 Load: 17.0 t ADT: 104

160TH ST

Fair

Over: STREAM

092150601, Butler, IA

Built 1900 Load: 17.0 t ADT: 35

C13

Fair

Over: SMALL STREAM

093161201, Butler, IA

Built 1900 Load: 17.0 t ADT: 727

LOCAL

Fair

Over: MIDDLE RACCOON RIVER

082331706, Carroll, IA

Built 1963 Load: 17.0 t ADT: 34

FM

Fair

Over: BRUSHY FORK CREEK

082343602, Carroll, IA

Built 1959 Load: 17.0 t ADT: 45

LOCAL - A AVE

Fair

Over: SMALL CREEK

090420602, Cherokee, IA

Built 1900 Load: 17.0 t ADT: 20

IOWA AVE

Fair

Over: STREAM

091042604, Clayton, IA

Built 1940 Load: 17.0 t ADT: 79

FANTAIL RD

Fair

Over: STREAM

091050106, Clayton, IA

Built 1925 Load: 17.0 t ADT: 15

OSTERDOCK RD

Fair

Over: JOLES CREEK

092033606, Clayton, IA

Built 1942 Load: 17.0 t ADT: 412

HAZEL RD

Fair

Over: STREAM

092042604, Clayton, IA

Built 1954 Load: 17.0 t ADT: 30

FORT RD

Fair

Over: STREAM

092052703, Clayton, IA

Built 1931 Load: 17.0 t ADT: 39

BUSH RD

Fair

Over: WILLOW CREEK

092060504, Clayton, IA

Built 1948 Load: 17.0 t ADT: 15

HARBER RD

Fair

Over: STREAM

093042102, Clayton, IA

Built 1954 Load: 17.0 t ADT: 29

CHARIOT RD

Fair

Over: STREAM

093050506, Clayton, IA

Built 1957 Load: 17.0 t ADT: 34

APPLE RD

Fair

Over: STREAM

094060404, Clayton, IA

Built 1949 Load: 17.0 t ADT: 403

CHARIOT RD

Fair

Over: SM STREAM

094061907, Clayton, IA

Built 1953 Load: 17.0 t ADT: 73

ABBEY RD

Fair

Over: STREAM

094062906, Clayton, IA

Built 1955 Load: 17.0 t ADT: 25

DOGWOOD AVE

Fair

Over: SILVER CREEK

095053002, Clayton, IA

Built 1930 Load: 17.0 t ADT: 98

ASPEN AVE

Fair

Over: ROBERTS CREEK

095060804, Clayton, IA

Built 1957 Load: 17.0 t ADT: 157

CONCORD AVE

Fair

Over: STREAM

095063504, Clayton, IA

Built 1948 Load: 17.0 t ADT: 47

LOCAL

Fair

Over: CREEK

078263104, Dallas, IA

Built 1935 Load: 17.0 t ADT: 300

I AVE

Fair

Over: CREEK

081282802, Dallas, IA

Built 1910 Load: 17.0 t ADT: 35

LOCAL

Fair

Over: SMALL STREAM

070133403, Davis, IA

Built 1988 Load: 17.0 t ADT: 11

LOCAL 180TH AVE

Fair

Over: SMALL STREAM

087050402, Delaware, IA

Built 1945 Load: 17.0 t ADT: 97

FM 110TH AVE

Fair

Over: BUFFALO CREEK

087062002, Delaware, IA

Built 1977 Load: 17.0 t ADT: 403

FM 280 AVE

Fair

Over: SMALL STREAM

090031804, Delaware, IA

Built 1962 Load: 17.0 t ADT: 98

FM 300 AVE

Fair

Over: BEAR CREEK

090032102, Delaware, IA

Built 1960 Load: 17.0 t ADT: 462

LOCAL

Fair

Over: CREEK

087E12804, Dubuque, IA

Built 1946 Load: 17.0 t ADT: 26

LOCAL

Fair

Over: SM CREEK

088022302, Dubuque, IA

Built 1950 Load: 17.0 t ADT: 50

FM

Fair

Over: SMALL STREAM

000000000, Dubuque, IA

Built 1950 Load: 17.0 t ADT: 769

LOCAL

Fair

Over: CREEK

089022003, Dubuque, IA

Built 1955 Load: 17.0 t ADT: 216

FM

Fair

Over: SMALL

090E12804, Dubuque, IA

Built 1942 Load: 17.0 t ADT: 250

UNION ST

Fair

Over: SMALL STREAM

000000000, Fayette, IA

Built 1958 Load: 17.0 t ADT: 1,518

LOCAL

Fair

Over: ACKLEY CREEK

094182301, Floyd, IA

Built 1919 Load: 17.0 t ADT: 26

218 TH

Fair

Over: STREAM

084303603, Greene, IA

Built 1937 Load: 17.0 t ADT: 11

FM

Fair

Over: SMALL CREEK

079301503, Guthrie, IA

Built 1966 Load: 17.0 t ADT: 45

FM

Fair

Over: STREAM

080321401, Guthrie, IA

Built 1950 Load: 17.0 t ADT: 26

FM 65TH ST

Fair

Over: NORTH TURKEY

099120203, Howard, IA

Built 1940 Load: 17.0 t ADT: 79

FM

Fair

Over: CREEK

089390502, Ida, IA

Built 1950 Load: 17.0 t ADT: 40

FM

Fair

Over: STREAM

086E30103, Jackson, IA

Built 1959 Load: 17.0 t ADT: 130

Showing 1,751-1,800 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.