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

Structurally Deficient

Over: STREAM

081123301, Iowa, IA

Built 1980 Load: 2.7 t ADT: 25

DERBY AVE SW

Structurally Deficient

Over: STREAM

078083402, Johnson, IA

Built 1954 Load: 2.7 t ADT: 60

LOCAL

Structurally Deficient

Over: STONY FORK

073221603, Lucas, IA

Built 1951 Load: 2.7 t ADT: 5

LOCAL ROAD

Structurally Deficient

Over: JOHNSON CREEK

098440502, Lyon, IA

Built 1900 Load: 2.7 t ADT: 5

LOCAL

Structurally Deficient

Over: STREAM

0894217, Woodbury, IA

Built 1965 Load: 2.7 t ADT: 11

LOCAL

Structurally Deficient

Over: CLEAR CREEK

081213501, Jasper, IA

Built 1974 Load: 2.8 t ADT: 26

M AVENUE

Structurally Deficient

Over: MIDDLE TARKIO RIVER

070370506, Page, IA

Built 1951 Load: 2.8 t ADT: 5

LOCAL

Structurally Deficient

Over: SPRING CK

086113001, Benton, IA

Built 1971 Load: 2.9 t ADT: 11

LOCAL

Structurally Deficient

Over: W BR WAPSINONOC CREEK

079042905, Cedar, IA

Built 1979 Load: 2.9 t ADT: 35

LOCAL

Structurally Deficient

Over: TRIB OF WELDON RIVER

068241702, Decatur, IA

Built 1910 Load: 3.0 t ADT: 5

FM

Structurally Deficient

Over: BRANCH TO CLANTON CREEK

074270104, Madison, IA

Built 1940 Load: 3.0 t ADT: 71

35TH AVE

Structurally Deficient

Over: CREEK

080E13406, Scott, IA

Built 1965 Load: 3.0 t ADT: 25

FM

Structurally Deficient

Over: STREAM

068271302, Decatur, IA

Built 1957 Load: 3.1 t ADT: 60

LOCAL

Structurally Deficient

Over: BR.BURR OAK CREEK

073080907, Jefferson, IA

Built 1962 Load: 3.1 t ADT: 40

LOCAL

Structurally Deficient

Over: CREEK

068332504, Taylor, IA

Built 1952 Load: 3.1 t ADT: 5

LOCAL

Structurally Deficient

Over: EAST PLATTE RIVER

071300905, Union, IA

Built 1969 Load: 3.1 t ADT: 15

LOCAL - 570TH

Structurally Deficient

Over: WATERWAY

074371002, Cass, IA

Built 1955 Load: 3.2 t ADT: 30

LOCAL RD

Structurally Deficient

Over: WEST NODAWAY RIVER

072362803, Montgomery, IA

Built 1940 Load: 3.2 t ADT: 45

LOCAL

Structurally Deficient

Over: MAYNES CREEK

091171802, Butler, IA

Built 1900 Load: 3.3 t ADT: 26

FM

Structurally Deficient

Over: WEST CREEK

073262704, Clarke, IA

Built 1965 Load: 3.3 t ADT: 29

LOCAL

Structurally Deficient

Over: WELDON RIVER

070243301, Decatur, IA

Built 1962 Load: 3.3 t ADT: 30

LOCAL

Structurally Deficient

Over: STREAM

080301005, Guthrie, IA

Built 1941 Load: 3.3 t ADT: 15

LOCAL

Structurally Deficient

Over: BEAVER CREEK

087200203, Hardin, IA

Built 1985 Load: 3.3 t ADT: 29

LOCAL

Structurally Deficient

Over: WALNUT CR

069203404, Wayne, IA

Built 1973 Load: 3.3 t ADT: 50

LOCAL

Structurally Deficient

Over: EAGLE CREEK

092252901, Wright, IA

Built 1975 Load: 3.3 t ADT: 11

LOCAL 90TH ST

Structurally Deficient

Over: CRANE CREEK

099132003, Howard, IA

Built 1951 Load: 3.4 t ADT: 21

LOCAL

Structurally Deficient

Over: TRIB S FK ENGLISH RIVER

077110304, Keokuk, IA

Built 1972 Load: 3.4 t ADT: 11

LOCAL ROAD

Structurally Deficient

Over: BLOOD RUN CREEK

100482302, Lyon, IA

Built 1900 Load: 3.4 t ADT: 90

FM

Structurally Deficient

Over: RICHLAND CREEK

082151902, Tama, IA

Built 1935 Load: 3.4 t ADT: 39

LOCAL

Structurally Deficient

Over: CREEK

068082606, Van Buren, IA

Built 1960 Load: 3.4 t ADT: 21

LOCAL

Structurally Deficient

Over: PIKE RUN

099241701, Winnebago, IA

Built 1976 Load: 3.4 t ADT: 11

LOCAL

Structurally Deficient

Over: FARMERS DITCH

086461204, Woodbury, IA

Built 1980 Load: 3.4 t ADT: 11

LOCAL

Structurally Deficient

Over: STREAM

089433101, Woodbury, IA

Built 1955 Load: 3.4 t ADT: 11

LOCAL

Structurally Deficient

Over: BR CARRUTHERS CREEK

073200304, Lucas, IA

Built 1957 Load: 3.5 t ADT: 82

LOCAL

Structurally Deficient

Over: DRAINAGE

076291906, Madison, IA

Built 1965 Load: 3.5 t ADT: 11

FM

Structurally Deficient

Over: DM RIVER

092302305, Humboldt, IA

Built 1905 Load: 3.6 t ADT: 30

LOCAL

Structurally Deficient

Over: BR OF CEDAR CREEK

071200207, Lucas, IA

Built 1940 Load: 3.6 t ADT: 11

FM

Structurally Deficient

Over: S RIVER

075251304, Warren, IA

Built 1940 Load: 3.6 t ADT: 71

LOCAL - SEATTLE

Structurally Deficient

Over: WATERWAY

074370605, Cass, IA

Built 1978 Load: 3.7 t ADT: 35

FM

Structurally Deficient

Over: BR IOWA RIVER

083151103, Tama, IA

Built 1995 Load: 3.7 t ADT: 717

FM

Structurally Deficient

Over: LITTLE WAPSIPINICON RVR

096130701, Chickasaw, IA

Built 1961 Load: 3.8 t ADT: 265

LOCAL RD

Structurally Deficient

Over: BLACK HAWK CREEK

088161602, Grundy, IA

Built 1971 Load: 3.8 t ADT: 11

LOCAL

Structurally Deficient

Over: BR OF BRUSH CREEK

072232003, Lucas, IA

Built 1953 Load: 3.8 t ADT: 41

FIELD ENTRANCE

Structurally Deficient

Over: STREAM (SDB)

068363602, Page, IA

Built 1979 Load: 3.8 t ADT: 10

FIELD ENTRANCE

Structurally Deficient

Over: SIDE DRAINAGE (SDB)

068083104, Van Buren, IA

Built 1976 Load: 3.8 t ADT: 10

MASON AVE

Structurally Deficient

Over: STREAM

089420804, Woodbury, IA

Built 1970 Load: 3.8 t ADT: 5

LOCAL

Structurally Deficient

Over: NORTH SKUNK RIVER

080180806, Jasper, IA

Built 1936 Load: 3.9 t ADT: 106

FM

Structurally Deficient

Over: SAND CREEK

071283005, Union, IA

Built 1963 Load: 3.9 t ADT: 50

LOCAL - CHICAGO

Structurally Deficient

Over: BUCK CREEK

077361801, Cass, IA

Built 1900 Load: 4.0 t ADT: 30

LOCAL

Structurally Deficient

Over: TRIB OF DICKENSON BRANCH

067260305, Decatur, IA

Built 1967 Load: 4.0 t ADT: 5

Showing 19,851-19,900 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.