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: BR MINERVA CR

085200903, Marshall, IA

Built 1984 Load: 26.8 t ADT: 26

LOCAL

Poor

Over: TRIB TO SOLDIER RIVER

084421103, Monona, IA

Built 1990 Load: 26.8 t ADT: 20

190TH ST

Poor

Over: WESTFIELD CREEK

092481901, Plymouth, IA

Built 1951 Load: 26.8 t ADT: 26

LOCAL

Poor

Over: SMALL

081130909, Poweshiek, IA

Built 1978 Load: 26.8 t ADT: 15

WALNUT AVENUE

Poor

Over: STREAM

073322604, Adams, IA

Built 1967 Load: 26.9 t ADT: 71

LOCAL

Poor

Over: BLUFF CREEK

085271701, Boone, IA

Built 1920 Load: 26.9 t ADT: 30

LOCAL

Poor

Over: W BR MILL CREEK

096413302, O'Brien, IA

Built 1925 Load: 26.9 t ADT: 26

M-63 / O AVE

Poor

Over: SNAKE CREEK

069372202, Page, IA

Built 1962 Load: 26.9 t ADT: 837

J-20/140TH ST

Poor

Over: UNNAMED STREAM

070372501, Page, IA

Built 1964 Load: 26.9 t ADT: 450

FIELD ENTRANCE

Poor

Over: STREAM (SDB)

069361403, Page, IA

Built 1900 Load: 26.9 t ADT: 10

LOCAL

Poor

Over: EAST PLATTE RIVER

071300301, Union, IA

Built 1981 Load: 26.9 t ADT: 30

FM

Poor

Over: DUTCH CREEK

075091804, Washington, IA

Built 1956 Load: 26.9 t ADT: 45

FM

Poor

Over: STREAM

078162209, Poweshiek, IA

Built 1949 Load: 27.0 t ADT: 45

LOCAL

Poor

Over: STREAM

080150103, Poweshiek, IA

Built 1968 Load: 27.0 t ADT: 11

5TH AVE

Poor

Over: DRAINAGE DITCH

089282700, Webster, IA

Built 1955 Load: 27.0 t ADT: 8,894

FM

Poor

Over: BUCKEYE CREEK

082123608, Benton, IA

Built 1973 Load: 27.1 t ADT: 100

LOCAL

Poor

Over: STEIN CK

085123001, Benton, IA

Built 1971 Load: 27.1 t ADT: 60

FM

Poor

Over: BR ROCK CK

086110502, Benton, IA

Built 1973 Load: 27.1 t ADT: 90

FM

Poor

Over: DD 9-13

088320503, Calhoun, IA

Built 1966 Load: 27.1 t ADT: 290

FM

Poor

Over: FOX RIVER

069140904, Davis, IA

Built 1973 Load: 27.1 t ADT: 1,260

LOCAL

Poor

Over: COAL CREEK

076130401, Keokuk, IA

Built 1967 Load: 27.1 t ADT: 34

FM

Poor

Over: ROCK RIVER

098462402, Lyon, IA

Built 1966 Load: 27.1 t ADT: 977

FM

Poor

Over: NO LIZARD CK DD #171

091313601, Pocahontas, IA

Built 1965 Load: 27.1 t ADT: 578

LOCAL

Poor

Over: OTTER CREEK

084152703, Tama, IA

Built 1920 Load: 27.1 t ADT: 5

FM

Poor

Over: WEST FORK LITTLE SIOUX

088453305, Woodbury, IA

Built 1963 Load: 27.1 t ADT: 469

LOCAL

Poor

Over: PAINT CREEK

097042603, Allamakee, IA

Built 1915 Load: 27.2 t ADT: 60

LOCAL

Poor

Over: ONION CREEK

084252502, Boone, IA

Built 1900 Load: 27.2 t ADT: 60

FM - OLIVE

Poor

Over: NISHNABOTNA RIVER

077363302, Cass, IA

Built 1961 Load: 27.2 t ADT: 1,524

FM 520TH ST

Poor

Over: IOWA RIVER

078062301, Johnson, IA

Built 1971 Load: 27.2 t ADT: 2,060

LOCAL

Poor

Over: BARRY CREEK

095401202, O'Brien, IA

Built 1938 Load: 27.2 t ADT: 21

LOCAL

Poor

Over: STREAM

078160101, Poweshiek, IA

Built 1975 Load: 27.2 t ADT: 40

FM

Poor

Over: RACCOON RIVER

087360101, Sac, IA

Built 1965 Load: 27.2 t ADT: 290

FM

Poor

Over: DEER CREEK

090301202, Webster, IA

Built 1968 Load: 27.2 t ADT: 379

FM

Poor

Over: WEST FORK CEDAR RIVER

091170802, Butler, IA

Built 1970 Load: 27.3 t ADT: 373

FM

Poor

Over: S RACCOON RIVER

078300605, Guthrie, IA

Built 1974 Load: 27.3 t ADT: 100

FM

Poor

Over: ROCK RIVER

098463501, Lyon, IA

Built 1970 Load: 27.3 t ADT: 399

FM

Poor

Over: S SKUNK RIVER

076153309, Mahaska, IA

Built 1967 Load: 27.3 t ADT: 430

310TH STREET

Poor

Over: WEST MILL CREEK

067382501, Page, IA

Built 1979 Load: 27.3 t ADT: 309

FM

Poor

Over: SALT CREEK

084132902, Tama, IA

Built 1969 Load: 27.3 t ADT: 363

FM

Poor

Over: WOLF CREEK

085151702, Tama, IA

Built 1970 Load: 27.3 t ADT: 530

FM

Poor

Over: DRAINAGE

087333101, Calhoun, IA

Built 1975 Load: 27.4 t ADT: 26

LOCAL

Poor

Over: SPRING BRANCH CREEK

094133403, Chickasaw, IA

Built 1987 Load: 27.4 t ADT: 21

LOCAL

Poor

Over: CREEK

096120702, Chickasaw, IA

Built 1971 Load: 27.4 t ADT: 51

LOCAL

Poor

Over: CREEK

096132008, Chickasaw, IA

Built 1973 Load: 27.4 t ADT: 10

LOCAL

Poor

Over: CREEK

096143004, Chickasaw, IA

Built 1972 Load: 27.4 t ADT: 29

LOCAL

Poor

Over: CREEK

096143201, Chickasaw, IA

Built 1971 Load: 27.4 t ADT: 30

LOCAL

Poor

Over: CREEK

096143601, Chickasaw, IA

Built 1970 Load: 27.4 t ADT: 41

LOCAL

Poor

Over: CREEK

097113004, Chickasaw, IA

Built 1975 Load: 27.4 t ADT: 21

LOCAL

Poor

Over: BRANCH CRANE CREEK

097122202, Chickasaw, IA

Built 1970 Load: 27.4 t ADT: 82

LOCAL ROAD

Poor

Over: NORTH FORK BEAVER

089172902, Grundy, IA

Built 1981 Load: 27.4 t ADT: 39

Showing 18,751-18,800 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.