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 - 710TH

Poor

Over: W NODAWAY

074351206, Cass, IA

Built 1977 Load: 20.2 t ADT: 11

LOCAL

Poor

Over: SMALL

096142401, Chickasaw, IA

Built 1978 Load: 20.2 t ADT: 41

HWY 215

Poor

Over: SMALL NATURAL STREAM

086190526, Hardin, IA

Built 1948 Load: 20.2 t ADT: 854

LOCAL

Poor

Over: LOCAL STREAM

073050702, Henry, IA

Built 1957 Load: 20.2 t ADT: 47

LOCAL 170TH ST

Poor

Over: LITTLE WAPSIPINICON

098143601, Howard, IA

Built 1950 Load: 20.2 t ADT: 80

LOCAL

Poor

Over: PRAIRIE CREEK

081203503, Jasper, IA

Built 1921 Load: 20.2 t ADT: 51

EVERGREEN AVE

Poor

Over: INDIAN CREEK

093471902, Plymouth, IA

Built 1900 Load: 20.2 t ADT: 20

LOCAL

Poor

Over: EAST RIVER

069320501, Taylor, IA

Built 1977 Load: 20.2 t ADT: 15

LOCAL

Poor

Over: BRANCH SQUAW CREEK

074243404, Warren, IA

Built 1960 Load: 20.2 t ADT: 51

LOCAL

Poor

Over: MIDDLE RIVER

077231204, Warren, IA

Built 1940 Load: 20.2 t ADT: 103

LOCAL

Poor

Over: EAGLE CREEK

092250402, Wright, IA

Built 1981 Load: 20.2 t ADT: 26

LOCAL

Poor

Over: EAGLE CREEK

092250801, Wright, IA

Built 1981 Load: 20.2 t ADT: 21

LOCAL

Poor

Over: SMALL STREAM

068193102, Appanoose, IA

Built 1987 Load: 20.3 t ADT: 11

E 76TH ST S

Poor

Over: ELK CREEK

079181602, Jasper, IA

Built 1962 Load: 20.3 t ADT: 47

FM

Poor

Over: MINERVA CREEK

084190801, Marshall, IA

Built 1981 Load: 20.3 t ADT: 39

LOCAL ROAD

Poor

Over: CREEK

099071703, Winneshiek, IA

Built 1900 Load: 20.3 t ADT: 39

LOCAL

Poor

Over: WOLF CREEK

088443501, Woodbury, IA

Built 1949 Load: 20.3 t ADT: 26

LOCAL(SHELBY!)

Poor

Over: CREEK

079363102, Audubon, IA

Built 1928 Load: 20.4 t ADT: 21

LOCAL

Poor

Over: E NISHNABOTNA RIVER

081351101, Audubon, IA

Built 1971 Load: 20.4 t ADT: 35

FM

Poor

Over: BRANCH MUD CREEK

084112303, Benton, IA

Built 1983 Load: 20.4 t ADT: 30

LOCAL

Poor

Over: MONTGOMERY CREEK

085253404, Boone, IA

Built 1915 Load: 20.4 t ADT: 15

LOCAL

Poor

Over: HARTGRAVE CK

092181910, Butler, IA

Built 1952 Load: 20.4 t ADT: 59

LOCAL

Poor

Over: SMALL

079011501, Cedar, IA

Built 1979 Load: 20.4 t ADT: 51

LOCAL

Poor

Over: OTTER CREEK

073252606, Clarke, IA

Built 1984 Load: 20.4 t ADT: 20

FM

Poor

Over: STEELE CREEK

067240204, Decatur, IA

Built 1952 Load: 20.4 t ADT: 40

P AVE

Poor

Over: UNAMED CREEK

095090306, Fayette, IA

Built 1952 Load: 20.4 t ADT: 44

LOCAL

Poor

Over: FLOOD CREEK

097183201, Floyd, IA

Built 1970 Load: 20.4 t ADT: 20

FM

Poor

Over: SOUTH RACOON RIVER

079312202, Guthrie, IA

Built 1952 Load: 20.4 t ADT: 79

FM

Poor

Over: BIG MINERVA CREEK

085201505, Marshall, IA

Built 1967 Load: 20.4 t ADT: 265

LOCAL

Poor

Over: CREEK

073150505, Wapello, IA

Built 1987 Load: 20.4 t ADT: 73

LOCAL

Poor

Over: E FORK WAPSIPINICON RVR

096131402, Chickasaw, IA

Built 1971 Load: 20.5 t ADT: 73

LOC 30TH ST

Poor

Over: NICHOLS CR

100112401, Howard, IA

Built 1947 Load: 20.5 t ADT: 62

S 44TH AVE E

Poor

Over: SLATER CREEK

079181401, Jasper, IA

Built 1979 Load: 20.5 t ADT: 41

LOCAL

Poor

Over: STREAM

067282202, Ringgold, IA

Built 1969 Load: 20.5 t ADT: 40

FM

Poor

Over: RACOON RIVER

088363604, Sac, IA

Built 1924 Load: 20.5 t ADT: 71

244TH AVE

Poor

Over: UPPER IOWA RIVER

099091007, Winneshiek, IA

Built 1924 Load: 20.5 t ADT: 108

LOCAL

Poor

Over: SMALL

070193001, Appanoose, IA

Built 1983 Load: 20.6 t ADT: 26

LOCAL

Poor

Over: CREEK

081360702, Audubon, IA

Built 1987 Load: 20.6 t ADT: 21

310TH ST

Poor

Over: CREEK

093140101, Bremer, IA

Built 1978 Load: 20.6 t ADT: 33

NATURE RD

Poor

Over: LITTLE TURKEY RIVER

095092609, Fayette, IA

Built 1960 Load: 20.6 t ADT: 255

U AVE.

Poor

Over: CRANE CREEK

095103408, Fayette, IA

Built 1911 Load: 20.6 t ADT: 29

LOCAL

Poor

Over: WILLOW CREEK

093430701, Plymouth, IA

Built 1941 Load: 20.6 t ADT: 60

FARM ENTRANCE

Poor

Over: SIDE DITCH

071130604, Wapello, IA

Built 1983 Load: 20.6 t ADT: 10

LOCAL

Poor

Over: STREAM

087441101, Woodbury, IA

Built 1970 Load: 20.6 t ADT: 20

LOCAL

Poor

Over: STREAM

069170505, Appanoose, IA

Built 1952 Load: 20.7 t ADT: 51

FM

Poor

Over: BONNELL CREEK

068062402, Lee, IA

Built 1949 Load: 20.7 t ADT: 370

LOCAL RD

Poor

Over: NORTH CLANTON CREEK

074280806, Madison, IA

Built 1937 Load: 20.7 t ADT: 60

3RD AVE

Poor

Over: INDIAN CREEK

000000000, Pottawattamie, IA

Built 1935 Load: 20.7 t ADT: 179

LOCAL

Poor

Over: STREAM

078162903, Poweshiek, IA

Built 1929 Load: 20.7 t ADT: 15

FM

Poor

Over: SMALL STREAM

069342603, Taylor, IA

Built 1938 Load: 20.7 t ADT: 139

Showing 18,051-18,100 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.