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

Poor

Over: CREEK

070080804, Van Buren, IA

Built 1971 Load: 11.7 t ADT: 16

LOCAL

Poor

Over: CANOE CREEK

099080906, Winneshiek, IA

Built 1924 Load: 11.7 t ADT: 20

LOCAL

Poor

Over: MIDDLE RACCOON RIVER

082340106, Carroll, IA

Built 1951 Load: 11.8 t ADT: 11

LOCAL

Poor

Over: CREEK

095132404, Chickasaw, IA

Built 1960 Load: 11.8 t ADT: 73

LOCAL

Poor

Over: MOSQUITO CREEK

079402903, Shelby, IA

Built 1917 Load: 11.8 t ADT: 35

240TH STREET

Poor

Over: SAYLINGS CREEK

071321401, Adams, IA

Built 1958 Load: 11.9 t ADT: 26

240TH STREET

Poor

Over: PLATTE RIVER

071321403, Adams, IA

Built 1958 Load: 11.9 t ADT: 34

POPLAR AVENUE

Poor

Over: LONZO CREEK

071333502, Adams, IA

Built 1957 Load: 11.9 t ADT: 50

HOLLY AVENUE

Poor

Over: WEST FORK 102 RIVER

071342104, Adams, IA

Built 1958 Load: 11.9 t ADT: 5

NOTCHWOOD AVE

Poor

Over: STREAM

072331602, Adams, IA

Built 1956 Load: 11.9 t ADT: 40

MULBERRY AVE

Poor

Over: STREAM

072331912, Adams, IA

Built 1962 Load: 11.9 t ADT: 5

DOGWOOD AVENUE

Poor

Over: WILLIAMS CREEK

073351102, Adams, IA

Built 1964 Load: 11.9 t ADT: 5

LOCAL

Poor

Over: DD 65

088322902, Calhoun, IA

Built 1929 Load: 11.9 t ADT: 20

LOCAL - 710TH

Poor

Over: WATERWAY

075352502, Cass, IA

Built 1955 Load: 11.9 t ADT: 11

LOCAL 460TH ST

Poor

Over: GREY CREEK

093402703, Cherokee, IA

Built 1927 Load: 11.9 t ADT: 15

LOCAL 470TH ST

Poor

Over: GREY CREEK

093403403, Cherokee, IA

Built 1920 Load: 11.9 t ADT: 45

120 TH

Poor

Over: STREAM

085321501, Greene, IA

Built 1957 Load: 11.9 t ADT: 26

FM

Poor

Over: NORWAY CREEK

083423401, Monona, IA

Built 1953 Load: 11.9 t ADT: 40

FM

Poor

Over: CROOKED CK DD #60

092311602, Pocahontas, IA

Built 1973 Load: 11.9 t ADT: 40

LOCAL

Poor

Over: STREAM

088370602, Sac, IA

Built 1981 Load: 11.9 t ADT: 30

LOCAL

Poor

Over: EAST FORK BIG CREEK

067270103, Decatur, IA

Built 1967 Load: 12.0 t ADT: 113

F AVE.

Poor

Over: GUNDLACH CR

091073202, Fayette, IA

Built 1921 Load: 12.0 t ADT: 29

170TH ST

Poor

Over: COULEE

093091301, Fayette, IA

Built 1915 Load: 12.0 t ADT: 44

250TH ST

Poor

Over: UNNAMED CREEK

095103607, Fayette, IA

Built 1916 Load: 12.0 t ADT: 49

S 88TH AVE W

Poor

Over: WALNUT CREEK

078210901, Jasper, IA

Built 1926 Load: 12.0 t ADT: 26

FM

Poor

Over: OTTER CREEK

073040302, Louisa, IA

Built 1955 Load: 12.0 t ADT: 35

150TH STREET

Poor

Over: WEST TARKIO RIVER

070383401, Page, IA

Built 1964 Load: 12.0 t ADT: 15

LOCAL

Poor

Over: W FK GRAND RIVER

068300303, Ringgold, IA

Built 1930 Load: 12.0 t ADT: 60

FM

Poor

Over: CREEK

096440701, Sioux, IA

Built 1949 Load: 12.0 t ADT: 20

LOCAL

Poor

Over: SMALL STREAM

072280806, Union, IA

Built 1940 Load: 12.0 t ADT: 26

LOCAL

Poor

Over: STREAM

090373102, Buena Vista, IA

Built 1975 Load: 12.1 t ADT: 20

LOCAL- 600TH ST

Poor

Over: MAPLE RIVER

090390501, Cherokee, IA

Built 1921 Load: 12.1 t ADT: 11

LOCAL

Poor

Over: WEST CREEK

073262104, Clarke, IA

Built 1949 Load: 12.1 t ADT: 26

320TH ST

Poor

Over: ROCK CREEK

067402604, Fremont, IA

Built 1962 Load: 12.1 t ADT: 15

LOCAL

Poor

Over: NORTH ENGLISH RIVER

079161201, Poweshiek, IA

Built 1983 Load: 12.1 t ADT: 30

LOCAL ROAD

Poor

Over: CREEK

100092403, Winneshiek, IA

Built 1900 Load: 12.1 t ADT: 39

LOCAL/FAIRVIEW

Poor

Over: STREAM

077373603, Cass, IA

Built 1979 Load: 12.2 t ADT: 15

FM

Poor

Over: WALNUT CREEK

073250408, Clarke, IA

Built 1976 Load: 12.2 t ADT: 459

LOCAL

Poor

Over: PANTHER CREEK

079282201, Dallas, IA

Built 1930 Load: 12.2 t ADT: 60

LOCAL

Poor

Over: KILGORE CREEK

068252607, Decatur, IA

Built 1982 Load: 12.2 t ADT: 21

LOCAL

Poor

Over: OTTER CREEK

073031102, Louisa, IA

Built 1920 Load: 12.2 t ADT: 30

LOCAL

Poor

Over: TRIB MAPLE RIVER

084430102, Monona, IA

Built 1900 Load: 12.2 t ADT: 20

LOCAL

Poor

Over: OCHEYEDAN RIVER

100412501, Osceola, IA

Built 1900 Load: 12.2 t ADT: 26

D AVENUE

Poor

Over: NISHNABOTNA RIVER

070392302, Page, IA

Built 1949 Load: 12.2 t ADT: 477

280TH ST

Poor

Over: DRY BRANCH

090440401, Plymouth, IA

Built 1900 Load: 12.2 t ADT: 11

310TH ST

Poor

Over: CREEK

090442001, Plymouth, IA

Built 1900 Load: 12.2 t ADT: 30

280TH ST

Poor

Over: SKUNK RIVER

082230501, Story, IA

Built 1929 Load: 12.2 t ADT: 60

LOCAL

Poor

Over: CREEK

070321804, Taylor, IA

Built 1959 Load: 12.2 t ADT: 5

LOCAL

Poor

Over: BR RACCOON RIVER

092362902, Buena Vista, IA

Built 1930 Load: 12.3 t ADT: 30

180TH ST

Poor

Over: WILLOW CREEK

080431405, Harrison, IA

Built 1975 Load: 12.3 t ADT: 15

Showing 16,951-17,000 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.