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

BLOOMINGTON RD

Good

Over: BIG CREEK

T83N R6W 23, Linn, IA

Built 2016 Load: 46.7 t ADT: 88

130TH AVE

Good

Over: SMALL CREEK

074193002, Marion, IA

Built 2018 Load: 46.7 t ADT: 30

E18 MARBLE RD

Good

Over: LITTLE ASHER CREEK

085181103, Marshall, IA

Built 2015 Load: 46.7 t ADT: 530

180TH ST

Good

Over: BR OF WHISKEY CREEK

9243130110, Plymouth, IA

Built 2016 Load: 46.7 t ADT: 15

150TH ST

Good

Over: WOLF CREEK

9345330110, Plymouth, IA

Built 2016 Load: 46.7 t ADT: 71

FM

Good

Over: CAMP CREEK

078222403, Polk, IA

Built 1993 Load: 46.7 t ADT: 150

E MLK JR PKWY

Good

Over: NS RR

078240207, Polk, IA

Built 2016 Load: 46.7 t ADT: 14,883

E MLK JR PKWY

Good

Over: UP RR

078240207, Polk, IA

Built 2016 Load: 46.7 t ADT: 14,883

IA 78

Good

Over: E. FORK CROOKED CREEK

At Jct. of SR X23, Henry, IA

Built 2003 Load: 46.8 t ADT: 640

US 30 WB

Good

Over: UPRR

0.5 MILE W OF JCT IA 146, Marshall, IA

Built 2003 Load: 46.9 t ADT: 7,050

MLK EB

Good

Over: DES MOINES RIVER

078240800, Polk, IA

Built 2010 Load: 46.9 t ADT: 4,276

MLK WB

Good

Over: DES MOINES RIVER

078240800, Polk, IA

Built 2010 Load: 46.9 t ADT: 4,079

GIBBON AVE

Good

Over: STREAM

74320709, Adair, IA

Built 2012 Load: 47.0 t ADT: 26

E24 33RD AVE DR

Good

Over: SPRING CREEK

085092504, Benton, IA

Built 2015 Load: 47.0 t ADT: 334

E53 S AVE

Good

Over: COON CREEK

082390103, Crawford, IA

Built 2016 Load: 47.0 t ADT: 50

390TH ST

Good

Over: DRAINAGE DITCH

086263203, Hamilton, IA

Built 2004 Load: 47.0 t ADT: 20

SR W21 (U AVE)

Good

Over: OLD MAN'S CREEK

079093306, Iowa, IA

Built 2012 Load: 47.0 t ADT: 450

LOCAL ROAD

Good

Over: DEER CREEK

080231701, Polk, IA

Built 2003 Load: 47.0 t ADT: 50

350TH ST

Good

Over: SMALL STREAM

086371001, Sac, IA

Built 2017 Load: 47.0 t ADT: 15

N44 LINWOOD AVE

Good

Over: SMALL STREAM

067340202, Taylor, IA

Built 2020 Load: 47.0 t ADT: 349

J40 220TH ST

Good

Over: REEDS CREEK

068080301, Van Buren, IA

Built 2022 Load: 47.0 t ADT: 530

IA 28

Good

Over: DRAINAGE DITCH

0.5 MILE N OF JCT. IA 92, Warren, IA

Built 1927 Load: 47.0 t ADT: 2,420

VALE RD

Good

Over: WOLF CREEK

070220303, Wayne, IA

Built 2017 Load: 47.0 t ADT: 30

JORDAN AVE

Good

Over: SHANGHAR CREEK BRANCH

074322702, Adair, IA

Built 2009 Load: 47.1 t ADT: 30

US 65

Good

Over: HONEY CREEK

AT JCT SR D55/280TH ST, Hardin, IA

Built 2008 Load: 47.1 t ADT: 1,820

US 6

Good

Over: HILTON CREEK

2.9 mi. W of Jct. IA 220, Iowa, IA

Built 2010 Load: 47.1 t ADT: 3,190

FM

Good

Over: MINERVA CREEK

085200904, Marshall, IA

Built 1997 Load: 47.1 t ADT: 147

EDDYVILLE RD

Good

Over: SMALL STREAM

072141005, Wapello, IA

Built 1988 Load: 47.1 t ADT: 2,600

FLEUR DR.

Good

Over: MIDDLE SOUTH CREEK

077240500, Warren, IA

Built 2002 Load: 47.1 t ADT: 4,643

WATROUS

Good

Over: LOST BRANCH

070210301, Wayne, IA

Built 2017 Load: 47.1 t ADT: 30

LOCAL

Good

Over: WILDCAT CK

084091702, Benton, IA

Built 2004 Load: 47.2 t ADT: 29

FM

Good

Over: WEST FORK CEDAR RIVER

091163402, Butler, IA

Built 2003 Load: 47.2 t ADT: 650

NEOLA AVE

Good

Over: HARDIN CREEK

084303204, Greene, IA

Built 1986 Load: 47.2 t ADT: 82

FM

Good

Over: CREEK

073191802, Monroe, IA

Built 2008 Load: 47.2 t ADT: 25

US 65

Good

Over: MINERVA CREEK

0.4 MILES SOUTH OF SR E18, Story, IA

Built 2001 Load: 47.2 t ADT: 1,930

LOCAL

Good

Over: LITTLE CEDAR CREEK

073133501, Wapello, IA

Built 2001 Load: 47.2 t ADT: 25

LOCAL

Good

Over: SMALL STREAM

070221303, Wayne, IA

Built 2000 Load: 47.2 t ADT: 11

STRAYER RD

Good

Over: TRIB TO BLACK HAWK CREEK

88-14-21-01-10, Black Hawk, IA

Built 1994 Load: 47.3 t ADT: 69

W GRESHAM RD

Good

Over: TRIB QUARTER SECTION RUN

90-13-11-01-10, Black Hawk, IA

Built 1995 Load: 47.3 t ADT: 34

WASHINGTON ST

Good

Over: PLUM CREEK

00000000000, Fremont, IA

Built 2012 Load: 47.3 t ADT: 179

XIRCUS AVE

Good

Over: LONG DICK CREEK

086232202, Hamilton, IA

Built 2022 Load: 47.3 t ADT: 30

LOCAL ROAD

Good

Over: BIG CREEK

081250401, Polk, IA

Built 1992 Load: 47.3 t ADT: 60

FM

Good

Over: LITTLE CREEK

081251601, Polk, IA

Built 1986 Load: 47.3 t ADT: 79

SE 16TH ST

Good

Over: SKUNK RIVER

A11700795, Story, IA

Built 2007 Load: 47.3 t ADT: 4,878

EB US 6

Good

Over: GOOSE CREEK

1.7 mi. W of Jct. I-74, Scott, IA

Built 2003 Load: 47.4 t ADT: 17,700

370TH AVE

Good

Over: BROPHY CREEK

082E51002, Clinton, IA

Built 1999 Load: 47.5 t ADT: 11

FM

Good

Over: CREEK

100361408, Dickinson, IA

Built 2001 Load: 47.5 t ADT: 478

LOCAL

Good

Over: NO.TURKEY CREEK

077313101, Adair, IA

Built 1992 Load: 47.6 t ADT: 51

LOCAL

Good

Over: DRAINAGE

098041503, Allamakee, IA

Built 2006 Load: 47.6 t ADT: 30

N NESBIT RD

Good

Over: CRANE CREEK

90-11-27-02-10, Black Hawk, IA

Built 2014 Load: 47.6 t ADT: 39

Showing 15,451-15,500 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.