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

190TH STREET

Fair

Over: SILVER CREEK WEST

082E32201, Clinton, IA

Built 1968 Load: 30.3 t ADT: 800

140TH STREET

Fair

Over: SPRING CREEK

083E62801, Clinton, IA

Built 1963 Load: 30.3 t ADT: 860

IA 2

Fair

Over: ELK CREEK

0.3 MI. W OF SR R18, Decatur, IA

Built 1985 Load: 30.3 t ADT: 1,350

FM SAND RD SE

Fair

Over: BUCK CREEK

077060204, Johnson, IA

Built 1964 Load: 30.3 t ADT: 1,210

FM SW NAPLES AV

Fair

Over: DIRTY FACE CREEK

078061704, Johnson, IA

Built 1980 Load: 30.3 t ADT: 270

FM 500TH ST

Fair

Over: BR DIRTY FACE CR

078071409, Johnson, IA

Built 1977 Load: 30.3 t ADT: 270

FM SW KANSAS

Fair

Over: STREAM

078071404, Johnson, IA

Built 1978 Load: 30.3 t ADT: 270

FINCH RD.

Fair

Over: BEERS CREEK

084010904, Jones, IA

Built 1977 Load: 30.3 t ADT: 30

IA 48

Fair

Over: FOUR MILE CREEK

1.0 E OF Jct. U.S. 59, Page, IA

Built 1995 Load: 30.3 t ADT: 2,960

FM

Fair

Over: INDIAN CREEK

081221202, Polk, IA

Built 1958 Load: 30.3 t ADT: 139

LOCAL

Fair

Over: MIDDLE 102 RIVER

067340603, Taylor, IA

Built 1995 Load: 30.3 t ADT: 5

FILBERT AVENUE

Fair

Over: MOORE CREEK

073340602, Adams, IA

Built 1964 Load: 30.4 t ADT: 45

LOCAL

Fair

Over: STERN CREEK

082121601, Benton, IA

Built 1984 Load: 30.4 t ADT: 34

LOCAL

Fair

Over: WILDCAT CREEK

084091904, Benton, IA

Built 1978 Load: 30.4 t ADT: 39

FM

Fair

Over: PRATT CREEK

085110402, Benton, IA

Built 1978 Load: 30.4 t ADT: 40

FM 252ND ST

Fair

Over: FLOOD PLAIN OF WAPSI R

091112103, Bremer, IA

Built 1985 Load: 30.4 t ADT: 432

US 218

Fair

Over: TRIB-SHELL ROCK RIVER

1.1 MI. N OF JCT. IA 3, Bremer, IA

Built 1996 Load: 30.4 t ADT: 8,300

FM

Fair

Over: MALONE CREEK

089092503, Buchanan, IA

Built 1969 Load: 30.4 t ADT: 285

FM QUONSET AVE

Fair

Over: W BR BUFFALO CK

090083504, Buchanan, IA

Built 1979 Load: 30.4 t ADT: 98

FM 140TH ST

Fair

Over: OTTER CREEK

090092803, Buchanan, IA

Built 1968 Load: 30.4 t ADT: 118

FM

Fair

Over: HARDING CREEK

086313501, Calhoun, IA

Built 1976 Load: 30.4 t ADT: 15

FM

Fair

Over: DD 195

086342702, Calhoun, IA

Built 1969 Load: 30.4 t ADT: 80

LOCAL

Fair

Over: E.CEDAR CR.

087311002, Calhoun, IA

Built 1978 Load: 30.4 t ADT: 30

LOCAL

Fair

Over: E CEDAR CREEK

087312102, Calhoun, IA

Built 1966 Load: 30.4 t ADT: 30

LOCAL

Fair

Over: CAMP CREEK

087340401, Calhoun, IA

Built 1974 Load: 30.4 t ADT: 15

LOCAL

Fair

Over: CAMP CREEK

087340402, Calhoun, IA

Built 1974 Load: 30.4 t ADT: 11

LOCAL

Fair

Over: CAMP CR

087340902, Calhoun, IA

Built 1970 Load: 30.4 t ADT: 15

LOCAL

Fair

Over: DD NO. 12

088312201, Calhoun, IA

Built 1971 Load: 30.4 t ADT: 20

LOCAL

Fair

Over: DD 9-13

089322601, Calhoun, IA

Built 1973 Load: 30.4 t ADT: 20

FM

Fair

Over: STORM CREEK

084341102, Carroll, IA

Built 1964 Load: 30.4 t ADT: 687

FM

Fair

Over: EAST BOYER RIVER

084361902, Carroll, IA

Built 1971 Load: 30.4 t ADT: 687

LOCAL/NEWPORT

Fair

Over: SEVEN MILE CREEK

075351101, Cass, IA

Built 1977 Load: 30.4 t ADT: 26

LOCAL - QUINCY

Fair

Over: SEVENMILE CREEK

075352901, Cass, IA

Built 1977 Load: 30.4 t ADT: 30

LOCAL/RICHLAND

Fair

Over: SMALL STREAM

075363201, Cass, IA

Built 1974 Load: 30.4 t ADT: 41

LOCAL - 725TH

Fair

Over: TURKEY CREEK

077343104, Cass, IA

Built 1973 Load: 30.4 t ADT: 30

FM - BOSTON

Fair

Over: BUCK CREEK

077360701, Cass, IA

Built 1974 Load: 30.4 t ADT: 26

FM

Fair

Over: ROCK CREEK

080010204, Cedar, IA

Built 1975 Load: 30.4 t ADT: 60

SB I 35

Fair

Over: BAILEY CREEK

2.7 MI. N Jct. SR C13, Cerro Gordo, IA

Built 1971 Load: 30.4 t ADT: 8,650

FM-SIMONSEN RD

Fair

Over: ROCK CREEK

090411005, Cherokee, IA

Built 1975 Load: 30.4 t ADT: 20

FM 580TH ST

Fair

Over: PERRY CREEK

091402901, Cherokee, IA

Built 1979 Load: 30.4 t ADT: 199

FM RIVER RD.

Fair

Over: PERRY CREEK

091402908, Cherokee, IA

Built 1973 Load: 30.4 t ADT: 748

FM

Fair

Over: WAPSIPINICON RIVER

096142701, Chickasaw, IA

Built 1967 Load: 30.4 t ADT: 59

FM

Fair

Over: WHITE BREAST CREEK

072252006, Clarke, IA

Built 1962 Load: 30.4 t ADT: 180

FM

Fair

Over: BRANCH OTTER CREEK

073242902, Clarke, IA

Built 1972 Load: 30.4 t ADT: 319

FM

Fair

Over: WEST CREEK

073273604, Clarke, IA

Built 1982 Load: 30.4 t ADT: 40

180TH AVE

Fair

Over: WILLOW CREEK

094370402, Clay, IA

Built 1979 Load: 30.4 t ADT: 50

FM 100TH AVE

Fair

Over: BR OCHEYEDAN R

096380602, Clay, IA

Built 1967 Load: 30.4 t ADT: 359

270TH ST

Fair

Over: BIG MEADOW CK

097350601, Clay, IA

Built 1976 Load: 30.4 t ADT: 20

DOMINO RD

Fair

Over: WOLF CREEK

092060205, Clayton, IA

Built 1973 Load: 30.4 t ADT: 619

C-02W

Fair

Over: VOLGA RIVER

009000510, Clayton, IA

Built 1975 Load: 30.4 t ADT: 690

Showing 5,601-5,650 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.