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

DEER CREEK RD

Fair

Over: STREAM

000000000, Johnson, IA

Built 1972 Load: 32.8 t ADT: 1,267

FM SUTLIFF RD

Fair

Over: CLEAR CREEK

081050102, Johnson, IA

Built 1974 Load: 32.8 t ADT: 610

FM

Fair

Over: CEDAR CREEK

071180403, Monroe, IA

Built 1975 Load: 32.8 t ADT: 90

FM

Fair

Over: CREEK

076041308, Muscatine, IA

Built 1954 Load: 32.8 t ADT: 180

FM RT C 56

Fair

Over: LIZARD CREEK

090311201, Pocahontas, IA

Built 1978 Load: 32.8 t ADT: 50

SB US 65

Fair

Over: SOUTH SKUNK RIVER

7.6 MILES N OF JCT I-80, Polk, IA

Built 2000 Load: 32.8 t ADT: 4,800

FM-COUGAR AVE

Fair

Over: PIGEON CREEK

076430503, Pottawattamie, IA

Built 1976 Load: 32.8 t ADT: 150

FM

Fair

Over: CEDAR CR

073132606, Wapello, IA

Built 1975 Load: 32.8 t ADT: 35

FM

Fair

Over: SOUTH FORK LONG CREEK

075070501, Washington, IA

Built 1979 Load: 32.8 t ADT: 2,280

FM

Fair

Over: DAVIS CREEK

076060105, Washington, IA

Built 1980 Load: 32.8 t ADT: 70

FM

Fair

Over: VILLAGE CREEK

099033305, Allamakee, IA

Built 1981 Load: 32.9 t ADT: 707

LOCAL

Fair

Over: BR CHARITON CREEK

071242503, Clarke, IA

Built 1985 Load: 32.9 t ADT: 40

FM 320TH ST

Fair

Over: BIG MEADOW CREEK

097363501, Clay, IA

Built 1978 Load: 32.9 t ADT: 80

FM

Fair

Over: BOONE RIVER

087263010, Hamilton, IA

Built 1939 Load: 32.9 t ADT: 478

I 380 SB

Fair

Over: EAST BLUE CREEK

2.3 mi. N of Jct. SR W35, Linn, IA

Built 1982 Load: 32.9 t ADT: 10,750

FM

Fair

Over: HICKORY CREEK

074202401, Marion, IA

Built 1945 Load: 32.9 t ADT: 400

US 34

Fair

Over: FOUR MILE CREEK

2 MI. E OF E JCT. US 169, Union, IA

Built 1971 Load: 32.9 t ADT: 3,040

LOCAL ROAD

Fair

Over: CREEK

098091402, Winneshiek, IA

Built 1900 Load: 32.9 t ADT: 59

LOCAL

Fair

Over: SMALL

099083106, Winneshiek, IA

Built 1978 Load: 32.9 t ADT: 39

FM

Fair

Over: PLUNGER CREEK

077302101, Adair, IA

Built 1963 Load: 33.0 t ADT: 79

LOCAL

Fair

Over: FORK PRAIRIE CREEK

083111902, Benton, IA

Built 1976 Load: 33.0 t ADT: 15

FM

Fair

Over: W BLUE CK

086092302, Benton, IA

Built 1974 Load: 33.0 t ADT: 69

E BIG ROCK RD

Fair

Over: ELK RUN CREEK

89-12-03-01-10, Black Hawk, IA

Built 1963 Load: 33.0 t ADT: 49

FM 252ND ST

Fair

Over: STREAM

091112403, Bremer, IA

Built 1972 Load: 33.0 t ADT: 334

212TH ST

Fair

Over: STREAM

092133105, Bremer, IA

Built 1966 Load: 33.0 t ADT: 638

FM

Fair

Over: BROOKS CREEK

091370701, Buena Vista, IA

Built 1977 Load: 33.0 t ADT: 34

LOCAL

Fair

Over: HARDING CREEK

086312601, Calhoun, IA

Built 1984 Load: 33.0 t ADT: 11

LOCAL

Fair

Over: W.CEDAR CR.

087313001, Calhoun, IA

Built 1978 Load: 33.0 t ADT: 26

FM

Fair

Over: W.CEDAR CR.

087313101, Calhoun, IA

Built 1979 Load: 33.0 t ADT: 15

FM

Fair

Over: D.D. 95

087313501, Calhoun, IA

Built 1976 Load: 33.0 t ADT: 26

FM

Fair

Over: D.D. 95

087313501, Calhoun, IA

Built 1974 Load: 33.0 t ADT: 26

LOCAL

Fair

Over: DRAINAGE DITCH

088310101, Calhoun, IA

Built 1974 Load: 33.0 t ADT: 15

LOCAL

Fair

Over: D.D. NO 12

088310301, Calhoun, IA

Built 1972 Load: 33.0 t ADT: 50

LOCAL

Fair

Over: COUNTY DRAIN #31

088311301, Calhoun, IA

Built 1984 Load: 33.0 t ADT: 11

LOCAL

Fair

Over: D.D. NO 31

088311302, Calhoun, IA

Built 1974 Load: 33.0 t ADT: 34

LOCAL

Fair

Over: WELSH SLOUGH

088312301, Calhoun, IA

Built 1974 Load: 33.0 t ADT: 20

LOCAL

Fair

Over: DD #31

088312304, Calhoun, IA

Built 1983 Load: 33.0 t ADT: 20

LOCAL RD

Fair

Over: D.D. NO 31

088312602, Calhoun, IA

Built 1974 Load: 33.0 t ADT: 34

LOCAL

Fair

Over: DD 12&22

088313402, Calhoun, IA

Built 1983 Load: 33.0 t ADT: 50

LOCAL

Fair

Over: DRAINAGE DITCH 9-13

088321701, Calhoun, IA

Built 1983 Load: 33.0 t ADT: 11

LOCAL

Fair

Over: LAKE CREEK

088321702, Calhoun, IA

Built 1985 Load: 33.0 t ADT: 34

LOCAL

Fair

Over: DD 9-13

088321702, Calhoun, IA

Built 1979 Load: 33.0 t ADT: 34

LOCAL

Fair

Over: DRAINAGE DITCH #67

088331001, Calhoun, IA

Built 1983 Load: 33.0 t ADT: 15

LOCAL

Fair

Over: DD 67

088331502, Calhoun, IA

Built 1976 Load: 33.0 t ADT: 45

LOCAL

Fair

Over: DD 67

088331602, Calhoun, IA

Built 1976 Load: 33.0 t ADT: 26

FM

Fair

Over: DD 67

088331702, Calhoun, IA

Built 1976 Load: 33.0 t ADT: 26

FM

Fair

Over: DD 67

088331901, Calhoun, IA

Built 1972 Load: 33.0 t ADT: 5

LOCAL

Fair

Over: CO DRAIN #1-54

088340901, Calhoun, IA

Built 1984 Load: 33.0 t ADT: 30

FM - 690TH

Fair

Over: WATERWAY

076351502, Cass, IA

Built 1970 Load: 33.0 t ADT: 450

220TH ST

Fair

Over: ROCK RUN CREEK

080030505, Cedar, IA

Built 1975 Load: 33.0 t ADT: 71

Showing 7,101-7,150 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.