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

Fair

Over: BEAMAN CREEK

085370302, Crawford, IA

Built 1999 Load: 38.5 t ADT: 15

CONGRESS ST

Fair

Over: SHELL ROCK RIVER

096180707, Floyd, IA

Built 2008 Load: 38.5 t ADT: 4,036

LOCAL

Fair

Over: BRUSHY CREEK

080312901, Guthrie, IA

Built 1988 Load: 38.5 t ADT: 50

FM

Fair

Over: BRUSHY CREEK

080321008, Guthrie, IA

Built 1975 Load: 38.5 t ADT: 428

LOCAL

Fair

Over: SMALL STREAM

073042002, Louisa, IA

Built 1950 Load: 38.5 t ADT: 47

FM

Fair

Over: LITTLE ROCK RIVER

099432001, Lyon, IA

Built 1973 Load: 38.5 t ADT: 190

LOCAL RD

Fair

Over: JONES CREEK

075261904, Madison, IA

Built 1989 Load: 38.5 t ADT: 50

FA-250TH ST

Fair

Over: KEG CREEK

073421704, Mills, IA

Built 1974 Load: 38.5 t ADT: 577

FM-EPPERSON AV

Fair

Over: KEG CREEK

073423001, Mills, IA

Built 1971 Load: 38.5 t ADT: 29

IA 183

Fair

Over: SOLDIER RIVER

1.1 mi. S of Jct. IA 141, Monona, IA

Built 1998 Load: 38.5 t ADT: 580

LOCAL

Fair

Over: SMALL STREAM

079220903, Polk, IA

Built 1995 Load: 38.5 t ADT: 60

FM

Fair

Over: GRAND RIVER

067290907, Ringgold, IA

Built 1973 Load: 38.5 t ADT: 270

E26/C.S. RD

Fair

Over: IOWAY CREEK

084242005, Story, IA

Built 1982 Load: 38.5 t ADT: 3,640

FM 160TH ST

Fair

Over: CREEK

072300503, Union, IA

Built 1952 Load: 38.5 t ADT: 150

US 63 NB

Fair

Over: STREAM

1.2 mi. S of Jct. IA 137, Wapello, IA

Built 1988 Load: 38.5 t ADT: 9,900

WB US 20

Fair

Over: BIG WHISKEY CREEK

1.9 mi. W of S.R. K42, Woodbury, IA

Built 2010 Load: 38.5 t ADT: 5,600

PELLA RD

Fair

Over: WEST NODAWAY CREEK

075342401, Cass, IA

Built 2016 Load: 38.6 t ADT: 15

LOCAL

Fair

Over: WHITE BREAST CREEK

071251104, Clarke, IA

Built 1972 Load: 38.6 t ADT: 5

FM 350TH ST

Fair

Over: OCHEYEDAN RIVER

096371803, Clay, IA

Built 1973 Load: 38.6 t ADT: 1,806

LOWER CEDAR RD

Fair

Over: CEDAR CREEK

092033203, Clayton, IA

Built 1930 Load: 38.6 t ADT: 44

IA 9

Fair

Over: DES MOINES RIVER

0.6 MI. W OF JCT. IA 4, Emmet, IA

Built 1975 Load: 38.6 t ADT: 8,200

LOCAL

Fair

Over: CREEK

097152101, Floyd, IA

Built 1991 Load: 38.6 t ADT: 20

LOCAL

Fair

Over: DD

088200203, Hardin, IA

Built 1988 Load: 38.6 t ADT: 30

LOCAL

Fair

Over: IOWA RIVER (SOUTH FORK)

088212806, Hardin, IA

Built 1989 Load: 38.6 t ADT: 16

IA 92

Fair

Over: OVER BNSF RR

1.4 mi. W of Jct. SR T25, Marion, IA

Built 1978 Load: 38.6 t ADT: 3,240

NB I-29

Fair

Over: HAYNIE SLOUGH

2.4 MI. S OF S JCT. US 34, Mills, IA

Built 1971 Load: 38.6 t ADT: 6,850

LOCAL

Fair

Over: MUD CREEK

078E10502, Muscatine, IA

Built 1988 Load: 38.6 t ADT: 104

FM

Fair

Over: WHISKEY CREEK

094413201, O'Brien, IA

Built 1990 Load: 38.6 t ADT: 159

FM

Fair

Over: INDIAN CREEK

068093004, Van Buren, IA

Built 1994 Load: 38.6 t ADT: 260

FM

Fair

Over: SMALL STREAM

070151408, Davis, IA

Built 1987 Load: 38.7 t ADT: 50

US 52

Fair

Over: N FORK MAQUOKETA RIVER

0.1 mi. S of Jct. SR C64, Dubuque, IA

Built 1985 Load: 38.7 t ADT: 3,990

LOCAL

Fair

Over: MOSQUITO CREEK

081302702, Guthrie, IA

Built 1981 Load: 38.7 t ADT: 20

SOUTH MAIN ST

Fair

Over: BRANCH OF KITTY CREEK

000000000, Jones, IA

Built 1972 Load: 38.7 t ADT: 6,117

FM

Fair

Over: NORTH RIVER

076270506, Madison, IA

Built 1990 Load: 38.7 t ADT: 89

LOCAL

Fair

Over: BUCK CREEK

077150910, Mahaska, IA

Built 1988 Load: 38.7 t ADT: 20

NB NW 100TH ST

Fair

Over: WALNUT CREEK

079253400, Polk, IA

Built 1988 Load: 38.7 t ADT: 3,579

SB NW 100TH ST

Fair

Over: WALNUT CREEK

079253400, Polk, IA

Built 1988 Load: 38.7 t ADT: 3,203

FM

Fair

Over: OPOSSUM CREEK

084091501, Benton, IA

Built 1959 Load: 38.8 t ADT: 1,100

180TH ST

Fair

Over: LITTLE WAPSIPINICON

092111301, Bremer, IA

Built 2002 Load: 38.8 t ADT: 26

FM

Fair

Over: CREEK

091380502, Buena Vista, IA

Built 1989 Load: 38.8 t ADT: 469

FM 370 AVENUE

Fair

Over: MILL CREEK

067401802, Fremont, IA

Built 1991 Load: 38.8 t ADT: 34

LOCAL

Fair

Over: FK OF BLACKHAWK CREEK

087172401, Grundy, IA

Built 1997 Load: 38.8 t ADT: 44

LOCAL

Fair

Over: MINERVA CREEK

086221002, Hardin, IA

Built 1994 Load: 38.8 t ADT: 47

EB US 30

Fair

Over: OVER CIC RR

0.8 MI. W OF JCT. I-380, Linn, IA

Built 1979 Load: 38.8 t ADT: 15,750

FM

Fair

Over: TARKIO CREEK

072370302, Montgomery, IA

Built 1988 Load: 38.8 t ADT: 270

NE 36TH STREET

Fair

Over: FOURMILE CREEK

080241201, Polk, IA

Built 1990 Load: 38.8 t ADT: 3,156

90TH ST

Fair

Over: CREEK

078E21502, Scott, IA

Built 1997 Load: 38.8 t ADT: 35

RIVER CAMP RD

Fair

Over: MUD CREEK OVERFLOW

080E21503, Scott, IA

Built 1991 Load: 38.8 t ADT: 290

NB I-35

Fair

Over: OVER UP RR

1.5 MILES N OF JCT US 30, Story, IA

Built 1966 Load: 38.8 t ADT: 18,000

LOCAL

Fair

Over: STREAM

0894220, Woodbury, IA

Built 2004 Load: 38.8 t ADT: 26

Showing 8,051-8,100 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.