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

087E22904, Dubuque, IA

Built 1940 Load: 17.2 t ADT: 20

LOCAL

Poor

Over: LITTLE MAQUOKETA RIVER

088010304, Dubuque, IA

Built 1952 Load: 17.2 t ADT: 128

RIVERVIEW DRIVE

Poor

Over: LITTLE TURKEY RIVER

000000000, Fayette, IA

Built 1954 Load: 17.2 t ADT: 1,344

LOCAL

Poor

Over: WINNEBAGO RIVER

095180801, Floyd, IA

Built 1900 Load: 17.2 t ADT: 59

BEEDS LAKE DR

Poor

Over: SPRING CR

092202001, Franklin, IA

Built 1967 Load: 17.2 t ADT: 227

LOCAL

Poor

Over: IOWAY CREEK

086253002, Hamilton, IA

Built 1952 Load: 17.2 t ADT: 15

LOCAL

Poor

Over: ODEBOLT CREEK

087392004, Ida, IA

Built 1957 Load: 17.2 t ADT: 50

FM

Poor

Over: OLD MANS CREEK

079093104, Iowa, IA

Built 1949 Load: 17.2 t ADT: 30

S 12TH AVE E

Poor

Over: ROCK CREEK

079170501, Jasper, IA

Built 1948 Load: 17.2 t ADT: 35

230TH ST

Poor

Over: RATHBURN CREEK

091430801, Plymouth, IA

Built 1900 Load: 17.2 t ADT: 30

270TH ST

Poor

Over: CARTER CREEK

091463503, Plymouth, IA

Built 1900 Load: 17.2 t ADT: 11

OTTER AVE

Poor

Over: WILLOW CREEK

093442902, Plymouth, IA

Built 1949 Load: 17.2 t ADT: 15

LOCAL

Poor

Over: WALNUT CREEK

081130104, Poweshiek, IA

Built 1951 Load: 17.2 t ADT: 40

FM

Poor

Over: CREEK

067341002, Taylor, IA

Built 1960 Load: 17.2 t ADT: 5

FM

Poor

Over: N. FORK LONG CREEK

076072802, Washington, IA

Built 1925 Load: 17.2 t ADT: 160

LOCAL

Poor

Over: STREAM

087420602, Woodbury, IA

Built 1942 Load: 17.2 t ADT: 5

LOCAL

Poor

Over: BEAVER CREEK

084282802, Boone, IA

Built 1900 Load: 17.3 t ADT: 11

FM

Poor

Over: SMALL STREAM

091171704, Butler, IA

Built 1969 Load: 17.3 t ADT: 373

FM

Poor

Over: LONG CREEK

070260903, Decatur, IA

Built 1957 Load: 17.3 t ADT: 26

MIDDLE ROAD

Poor

Over: BRUSH CREEK

APPROX. 600' E. OF RD. H, Des Moines, IA

Built 1946 Load: 17.3 t ADT: 10

270TH ST

Poor

Over: CREEK

097350301, Dickinson, IA

Built 1926 Load: 17.3 t ADT: 41

NEPTUNE ST

Poor

Over: S. SKUNK RIVER

079201405, Jasper, IA

Built 1948 Load: 17.3 t ADT: 60

LOCAL

Poor

Over: SMALL STREAM

081191404, Jasper, IA

Built 1939 Load: 17.3 t ADT: 30

FM

Poor

Over: HOWERDON CREEK

076292202, Madison, IA

Built 1972 Load: 17.3 t ADT: 597

BANCROFT AVE

Poor

Over: BIG SLOUGH CREEK

077041706, Muscatine, IA

Built 1937 Load: 17.3 t ADT: 45

C AVENUE

Poor

Over: WEST TARKIO RIVER

067391602, Page, IA

Built 1957 Load: 17.3 t ADT: 60

J-28 / 170TH ST

Poor

Over: TARKIO CREEK

069381101, Page, IA

Built 1956 Load: 17.3 t ADT: 60

G AVENUE

Poor

Over: W TARKIO RIVER

069382002, Page, IA

Built 1972 Load: 17.3 t ADT: 20

190TH ST

Poor

Over: MINK CREEK

092462201, Plymouth, IA

Built 1947 Load: 17.3 t ADT: 15

FM

Poor

Over: LOTTS CREEK

067292501, Ringgold, IA

Built 1957 Load: 17.3 t ADT: 11

LOCAL

Poor

Over: PLATTE RIVER

069313401, Ringgold, IA

Built 1955 Load: 17.3 t ADT: 29

LOCAL

Poor

Over: ODEBOLT CREEK

087382804, Sac, IA

Built 1981 Load: 17.3 t ADT: 15

LOCAL

Poor

Over: DRY CK

083091401, Benton, IA

Built 1973 Load: 17.4 t ADT: 50

LOCAL

Poor

Over: N FORK CAMP CR

088341102, Calhoun, IA

Built 1900 Load: 17.4 t ADT: 26

LOCAL

Poor

Over: ROCK CREEK

081031104, Cedar, IA

Built 1915 Load: 17.4 t ADT: 30

FM

Poor

Over: BRUSHY CREEK

081333606, Guthrie, IA

Built 1952 Load: 17.4 t ADT: 71

LOCAL

Poor

Over: S BR BIG CREEK

071050205, Henry, IA

Built 1996 Load: 17.4 t ADT: 5

J-31/185TH ST

Poor

Over: EAST NODAWAY RIVER

069361307, Page, IA

Built 1960 Load: 17.4 t ADT: 190

LOCAL

Poor

Over: STREAM

067200502, Wayne, IA

Built 1980 Load: 17.4 t ADT: 11

FM

Poor

Over: CHARITON RIVER

068172404, Appanoose, IA

Built 1956 Load: 17.5 t ADT: 40

FM - BOSTON

Poor

Over: NISHNABOTNA RIVER

077361205, Cass, IA

Built 1951 Load: 17.5 t ADT: 131

LOCAL

Poor

Over: SMALL

094143301, Chickasaw, IA

Built 1983 Load: 17.5 t ADT: 47

FM

Poor

Over: JONATHON CREEK

069241805, Decatur, IA

Built 1961 Load: 17.5 t ADT: 40

LOCAL

Poor

Over: CREEK

087E12704, Dubuque, IA

Built 1936 Load: 17.5 t ADT: 110

LOCAL

Poor

Over: CREEK

084E63504, Jackson, IA

Built 1938 Load: 17.5 t ADT: 110

SW 520TH ST

Poor

Over: DEER CREEK

078082001, Johnson, IA

Built 1900 Load: 17.5 t ADT: 35

FM

Poor

Over: OTTER CR

073030304, Louisa, IA

Built 1959 Load: 17.5 t ADT: 80

LOCAL RD

Poor

Over: S FORK CLANTON CREEK

074283606, Madison, IA

Built 1978 Load: 17.5 t ADT: 34

LOCAL

Poor

Over: STREAM

087361302, Sac, IA

Built 1924 Load: 17.5 t ADT: 26

LOCAL

Poor

Over: SALT CREEK

083132307, Tama, IA

Built 1927 Load: 17.5 t ADT: 59

Showing 17,651-17,700 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.