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 SPRUCE AVE

Structurally Deficient

Over: MAYNES CREEK

091191802, Franklin, IA

Built 1952 Load: 4.0 t ADT: 49

LOCAL

Structurally Deficient

Over: PRAIRIE CREEK

093271401, Humboldt, IA

Built 1900 Load: 4.0 t ADT: 15

LOCAL RD

Structurally Deficient

Over: JONES CREEK

075273104, Madison, IA

Built 1979 Load: 4.0 t ADT: 45

LCL-MARH AVE

Structurally Deficient

Over: NISHNA RIVER

071410201, Mills, IA

Built 1940 Load: 4.0 t ADT: 40

FM

Structurally Deficient

Over: CALHOUN CO DD

089320801, Calhoun, IA

Built 1976 Load: 4.1 t ADT: 45

LOCAL

Structurally Deficient

Over: BRANCH OF BEAVER CREEK

089170602, Grundy, IA

Built 1953 Load: 4.1 t ADT: 40

LOCAL ROAD

Structurally Deficient

Over: BEAVER CREEK

089170205, Grundy, IA

Built 1978 Load: 4.1 t ADT: 20

LOCAL

Structurally Deficient

Over: SM STREAM

074071710, Washington, IA

Built 1934 Load: 4.1 t ADT: 11

LOCAL

Structurally Deficient

Over: WOLF CREEK

089432802, Woodbury, IA

Built 1960 Load: 4.1 t ADT: 15

LOCAL

Structurally Deficient

Over: WEST LITTLE RIVER

069261103, Decatur, IA

Built 1930 Load: 4.2 t ADT: 5

LOCAL

Structurally Deficient

Over: DOWD CREEK

086182002, Grundy, IA

Built 1955 Load: 4.2 t ADT: 59

LOCAL

Structurally Deficient

Over: TROUBLESOME CREEK

079332902, Guthrie, IA

Built 1957 Load: 4.2 t ADT: 20

LOCAL

Structurally Deficient

Over: N CHEQUEST LAKE CREEK

070123004, Davis, IA

Built 1940 Load: 4.3 t ADT: 15

LOCAL ROAD

Structurally Deficient

Over: BRANCH BLACK HAWK CREEK

087160203, Grundy, IA

Built 1971 Load: 4.3 t ADT: 26

LOCAL

Structurally Deficient

Over: TRIB TO MIDDLE RIVER

078332402, Guthrie, IA

Built 1966 Load: 4.3 t ADT: 34

MEDFORD AVE

Structurally Deficient

Over: WILLOW RIVER

079432102, Harrison, IA

Built 1900 Load: 4.3 t ADT: 89

HOWARD AVE

Structurally Deficient

Over: BR CRANE CREEK

098132004, Howard, IA

Built 1947 Load: 4.3 t ADT: 48

LOCAL

Structurally Deficient

Over: BRANCH NORTH WOLF CREEK

074220802, Warren, IA

Built 1950 Load: 4.3 t ADT: 15

200TH

Structurally Deficient

Over: CREEK

095201801, Cerro Gordo, IA

Built 1937 Load: 4.4 t ADT: 21

LOCAL

Structurally Deficient

Over: CARTERS CREEK

068142102, Davis, IA

Built 1967 Load: 4.4 t ADT: 30

FM

Structurally Deficient

Over: CREEK

088193105, Hardin, IA

Built 1977 Load: 4.4 t ADT: 73

LOCAL

Structurally Deficient

Over: BRUSH CREEK

082172705, Marshall, IA

Built 1977 Load: 4.4 t ADT: 47

LOCAL

Structurally Deficient

Over: PIKE CREEK

076041603, Muscatine, IA

Built 1900 Load: 4.4 t ADT: 41

FILBERT AVENUE

Structurally Deficient

Over: WEST FORK 102 RIVER

071343102, Adams, IA

Built 1984 Load: 4.5 t ADT: 5

LOCAL

Structurally Deficient

Over: VILLAGE CREEK

098031806, Allamakee, IA

Built 1900 Load: 4.5 t ADT: 10

KIPLING AVE.

Structurally Deficient

Over: COLD WATER CREEK

093171404, Butler, IA

Built 1915 Load: 4.5 t ADT: 30

LOCAL

Structurally Deficient

Over: TRIB FABIUS CREEK

067140705, Davis, IA

Built 1966 Load: 4.5 t ADT: 11

LOCAL

Structurally Deficient

Over: OLD MAN'S CREEK

080113602, Iowa, IA

Built 1975 Load: 4.5 t ADT: 34

LOCAL

Structurally Deficient

Over: CREEK

083171108, Marshall, IA

Built 1916 Load: 4.5 t ADT: 145

KIWI AVENUE

Structurally Deficient

Over: BUCK CREEK

068382308, Page, IA

Built 1994 Load: 4.5 t ADT: 20

165TH ST

Structurally Deficient

Over: WEST BRANCH FLOYD RIVER

092450603, Plymouth, IA

Built 1911 Load: 4.5 t ADT: 120

LOCAL

Structurally Deficient

Over: E BRANCH W. NISH. RIVER

801337, Shelby, IA

Built 1920 Load: 4.5 t ADT: 26

LOCAL

Structurally Deficient

Over: STREAM

068200104, Wayne, IA

Built 1980 Load: 4.5 t ADT: 5

LOCAL

Structurally Deficient

Over: WALNUT CR

069203604, Wayne, IA

Built 1977 Load: 4.5 t ADT: 40

327TH AVE

Structurally Deficient

Over: CEDAR CREEK

071200208, Lucas, IA

Built 1954 Load: 4.6 t ADT: 26

LOCAL

Structurally Deficient

Over: MUD CREEK

078021108, Muscatine, IA

Built 1954 Load: 4.6 t ADT: 47

LOCAL

Structurally Deficient

Over: FARMERS DITCH

087460601, Woodbury, IA

Built 1900 Load: 4.6 t ADT: 30

LOCAL

Structurally Deficient

Over: DRAINAGE DITCH

090381801, Buena Vista, IA

Built 1971 Load: 4.8 t ADT: 30

LOCAL

Structurally Deficient

Over: EAST BRANCH LICK CREEK

071103004, Jefferson, IA

Built 1950 Load: 4.8 t ADT: 30

FM

Structurally Deficient

Over: DRAINAGE

076152401, Mahaska, IA

Built 1951 Load: 4.8 t ADT: 35

FM E-66

Structurally Deficient

Over: OSCAR CREEK

000000000, Linn, IA

Built 1917 Load: 4.9 t ADT: 640

LOCAL

Structurally Deficient

Over: EAST SOLDIER RIVER

084413102, Crawford, IA

Built 1957 Load: 5.0 t ADT: 34

LOCAL

Structurally Deficient

Over: LYNN CREEK

072070103, Henry, IA

Built 1974 Load: 5.0 t ADT: 30

LOCAL

Structurally Deficient

Over: TRIB DES MOINES RIVER

070112203, Van Buren, IA

Built 1977 Load: 5.0 t ADT: 16

LOCAL

Structurally Deficient

Over: STREAM

086452503, Woodbury, IA

Built 1952 Load: 5.1 t ADT: 45

LOCAL ROAD

Structurally Deficient

Over: BRANCH BEAVER CREEK

089150801, Grundy, IA

Built 1975 Load: 5.2 t ADT: 100

LOCAL

Structurally Deficient

Over: STREAM

079312103, Guthrie, IA

Built 1957 Load: 5.2 t ADT: 29

FM

Structurally Deficient

Over: DRAINAGE DITCH 36

092253502, Wright, IA

Built 1968 Load: 5.2 t ADT: 80

LOCAL

Structurally Deficient

Over: PRAIRIE CREEK

084113202, Benton, IA

Built 1947 Load: 5.3 t ADT: 50

LOCAL/KEYSTONE

Structurally Deficient

Over: CREEK

076342801, Cass, IA

Built 1900 Load: 5.3 t ADT: 26

Showing 19,901-19,950 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.