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 C-70

Fair

Over: WEST FORK LITTLE SIOUX

090443503, Plymouth, IA

Built 1961 Load: 21.1 t ADT: 459

LOCAL

Fair

Over: EAST BRANCH KEG CREEK

078402002, Shelby, IA

Built 1954 Load: 21.1 t ADT: 30

LOCAL

Fair

Over: SMALL STREAM

095452601, Sioux, IA

Built 1954 Load: 21.1 t ADT: 50

310TH ST

Fair

Over: BALLARD CREEK

082242409, Story, IA

Built 1936 Load: 21.1 t ADT: 100

160TH ST

Fair

Over: KEIGLEY BRANCH

084240101, Story, IA

Built 1915 Load: 21.1 t ADT: 30

IA 96

Fair

Over: WOLF CREEK

1.6 MILES W OF JCT. US 63, Tama, IA

Built 1955 Load: 21.1 t ADT: 1,320

2ND AVE S

Fair

Over: DES MOINES RIVER

0.6 mi. S of N jct US 169, Webster, IA

Built 1959 Load: 21.1 t ADT: 3,050

FM

Fair

Over: STREAM

088420303, Woodbury, IA

Built 1950 Load: 21.1 t ADT: 330

LOCAL

Fair

Over: BIG WHISKEY CREEK

089450602, Woodbury, IA

Built 2006 Load: 21.1 t ADT: 26

LOCAL

Fair

Over: SHANGHAR CREEK

074321403, Adair, IA

Built 1945 Load: 21.2 t ADT: 15

LOCAL

Fair

Over: BUCKEYE CK

082122210, Benton, IA

Built 1975 Load: 21.2 t ADT: 120

LOCAL

Fair

Over: BUCKEYE CREEK

082123606, Benton, IA

Built 1972 Load: 21.2 t ADT: 71

LOCAL

Fair

Over: WILD CAT CK

084090902, Benton, IA

Built 1972 Load: 21.2 t ADT: 168

LOCAL

Fair

Over: WILD CAT CREEK

084103401, Benton, IA

Built 1974 Load: 21.2 t ADT: 26

LOCAL

Fair

Over: BR HINKLE CK

085112501, Benton, IA

Built 1978 Load: 21.2 t ADT: 60

LOCAL

Fair

Over: BR BEAR CK

086101107, Benton, IA

Built 1972 Load: 21.2 t ADT: 33

LOCAL

Fair

Over: ROCK CK

086122604, Benton, IA

Built 1974 Load: 21.2 t ADT: 20

LOCAL

Fair

Over: BR CEDAR RIVER

086121203, Benton, IA

Built 1973 Load: 21.2 t ADT: 20

130TH ST

Fair

Over: STREAM

093122405, Bremer, IA

Built 1962 Load: 21.2 t ADT: 29

LOCAL

Fair

Over: D D #34 (RACCOON)

092361602, Buena Vista, IA

Built 1978 Load: 21.2 t ADT: 15

LOCAL

Fair

Over: BR RACCOON RIVER

093352002, Buena Vista, IA

Built 1970 Load: 21.2 t ADT: 30

180TH ST

Fair

Over: SHEEL ROCK RIVER BRANCH

092151603, Butler, IA

Built 1977 Load: 21.2 t ADT: 51

LOCAL - 765TH

Fair

Over: WEST NODAWAY CREEK

075342402, Cass, IA

Built 1976 Load: 21.2 t ADT: 15

FM

Fair

Over: BR BIG ELKHORN CK

079012603, Cedar, IA

Built 1978 Load: 21.2 t ADT: 80

BUCKEYE RD

Fair

Over: W BR WAPSINONOC CREEK

079042907, Cedar, IA

Built 1981 Load: 21.2 t ADT: 120

CHARLES AVE

Fair

Over: GOWER CREEK

080041602, Cedar, IA

Built 1977 Load: 21.2 t ADT: 50

WHEELERWOOD

Fair

Over: WINNEBAGO RIVER

097212404, Cerro Gordo, IA

Built 1952 Load: 21.2 t ADT: 11

US 59

Fair

Over: SILVER CREEK

0.7 mi. S of IA 31, Cherokee, IA

Built 1972 Load: 21.2 t ADT: 2,200

LOCAL

Fair

Over: BEAVER CREEK

096143103, Chickasaw, IA

Built 1979 Load: 21.2 t ADT: 41

LOCAL

Fair

Over: ELK CREEK

097132002, Chickasaw, IA

Built 1975 Load: 21.2 t ADT: 88

NETTLE AVE

Fair

Over: MAYNES CR

091203010, Franklin, IA

Built 1971 Load: 21.2 t ADT: 26

LOC-SPOKANE AVE

Fair

Over: PICAYUNE CREEK

080410512, Harrison, IA

Built 1979 Load: 21.2 t ADT: 11

FM 190TH ST

Fair

Over: BOHEMIAN CREEK

097111101, Howard, IA

Built 1976 Load: 21.2 t ADT: 80

FM 170TH ST

Fair

Over: LITTLE TURKEY RIVER

098113101, Howard, IA

Built 1973 Load: 21.2 t ADT: 25

LOCAL

Fair

Over: DD

093293202, Humboldt, IA

Built 1953 Load: 21.2 t ADT: 40

LOCAL

Fair

Over: SMALL CREEK

085E43603, Jackson, IA

Built 1930 Load: 21.2 t ADT: 11

FM MORSE RD

Fair

Over: RAPID CR

080050903, Johnson, IA

Built 1930 Load: 21.2 t ADT: 1,220

FM

Fair

Over: STREAM

076122308, Keokuk, IA

Built 1977 Load: 21.2 t ADT: 30

FM

Fair

Over: TRIB S FK ENGLISH RIVER

077100206, Keokuk, IA

Built 1978 Load: 21.2 t ADT: 35

FM

Fair

Over: STREAM

077130401, Keokuk, IA

Built 1963 Load: 21.2 t ADT: 50

LOC 150TH AVE

Fair

Over: LOTTS CREEK

094300801, Kossuth, IA

Built 1984 Load: 21.2 t ADT: 81

LOC 210TH AVE

Fair

Over: PRAIRIE CREEK

095273302, Kossuth, IA

Built 1977 Load: 21.2 t ADT: 11

LOC 190TH ST

Fair

Over: LOTTS CREEK

095302001, Kossuth, IA

Built 1982 Load: 21.2 t ADT: 30

LOC 180TH ST

Fair

Over: LOTTS CREEK

095302901, Kossuth, IA

Built 1976 Load: 21.2 t ADT: 41

LOC 170TH AVE

Fair

Over: LOTTS CREEK

095303201, Kossuth, IA

Built 1976 Load: 21.2 t ADT: 21

LOC 200TH AVE

Fair

Over: PLUM CREEK

096271702, Kossuth, IA

Built 1974 Load: 21.2 t ADT: 41

LOC 280TH ST

Fair

Over: LINDNER CREEK

096280201, Kossuth, IA

Built 1977 Load: 21.2 t ADT: 30

LOC 175TH AVE

Fair

Over: PLUM CREEK

096281406, Kossuth, IA

Built 1984 Load: 21.2 t ADT: 15

LOC 80TH AVE

Fair

Over: BLACK CAT CREEK

096290502, Kossuth, IA

Built 1984 Load: 21.2 t ADT: 50

FM 180TH AVE

Fair

Over: LINDNER CREEK

097283602, Kossuth, IA

Built 1977 Load: 21.2 t ADT: 26

Showing 2,901-2,950 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.