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

110TH AVE

Good

Over: DUCK CREEK

078E21302, Scott, IA

Built 2002 Load: 52.9 t ADT: 570

LOCAL

Good

Over: SIX MILE CREEK

095472402, Sioux, IA

Built 2003 Load: 52.9 t ADT: 45

360TH ST

Good

Over: WEST BRANCH

096441901, Sioux, IA

Built 2000 Load: 52.9 t ADT: 26

L 14

Good

Over: OTTER CREEK OVERFLOW

097440102, Sioux, IA

Built 1991 Load: 52.9 t ADT: 1,267

FM

Good

Over: RICHLAND CREEK

082142006, Tama, IA

Built 1996 Load: 52.9 t ADT: 265

IRR FM

Good

Over: RAVEN CREEK

082160302, Tama, IA

Built 2000 Load: 52.9 t ADT: 471

FM

Good

Over: MIDDLE PLATTE RIVER

072311302, Union, IA

Built 2005 Load: 52.9 t ADT: 1,055

LOCAL

Good

Over: INDIAN CREEK

067080604, Van Buren, IA

Built 1996 Load: 52.9 t ADT: 35

US 63 NB

Good

Over: FUDGE CREEK

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

Built 1988 Load: 52.9 t ADT: 4,950

FM

Good

Over: PAINTER CREEK

075252702, Warren, IA

Built 2007 Load: 52.9 t ADT: 747

FM

Good

Over: SOUTH WALKER CREEK

070202602, Wayne, IA

Built 2001 Load: 52.9 t ADT: 310

HAYES AVE

Good

Over: SOUTH LIZARD CREEK

089293204, Webster, IA

Built 2005 Load: 52.9 t ADT: 71

FM

Good

Over: WOLF CREEK

0874429, Woodbury, IA

Built 2005 Load: 52.9 t ADT: 26

LOCAL

Good

Over: MCELHANEY CREEK

089442702, Woodbury, IA

Built 1994 Load: 52.9 t ADT: 40

LOCAL

Good

Over: STREAM

089443006, Woodbury, IA

Built 1997 Load: 52.9 t ADT: 80

FM

Good

Over: OTTER CREEK

092261504, Wright, IA

Built 2006 Load: 52.9 t ADT: 223

E 16 D AVE

Good

Over: BIG CREEK

085392101, Crawford, IA

Built 2020 Load: 53.1 t ADT: 577

STRAWBRIDGE RD

Good

Over: RAPID CREEK

T80NR5W, 9 & 16, Johnson, IA

Built 2019 Load: 53.1 t ADT: 11

S34 140TH ST

Good

Over: STREAM

068212902, Wayne, IA

Built 2016 Load: 53.1 t ADT: 60

262ND ST

Good

Over: AMES CREEK

081E42901, Clinton, IA

Built 2003 Load: 53.2 t ADT: 580

FM

Good

Over: SMALL STREAM

082412308, Crawford, IA

Built 1958 Load: 53.2 t ADT: 60

IA 9

Good

Over: ROCK CREEK

5.8 MI. W of W Jct US 218, Mitchell, IA

Built 1992 Load: 53.2 t ADT: 2,340

US 6

Good

Over: GRAYBILL CREEK

2.6 MI. E OF E JCT US 59, Pottawattamie, IA

Built 1991 Load: 53.2 t ADT: 1,120

IA 149

Good

Over: NORTH FORK ENGLISH RIVER

0.8 MI. S OF SR V66, Iowa, IA

Built 1987 Load: 53.3 t ADT: 2,720

I-35

Good

Over: DRAINAGE DITCH

0.4 mi. N of Jct. SR B60, Cerro Gordo, IA

Built 1972 Load: 53.4 t ADT: 17,800

330 AVENUE

Good

Over: KILPATRICK CREEK

070410302, Fremont, IA

Built 1990 Load: 53.4 t ADT: 259

J23 170TH ST

Good

Over: EAST RIVER

069331201, Taylor, IA

Built 1990 Load: 53.4 t ADT: 309

LOCAL

Good

Over: DRY CK

083093001, Benton, IA

Built 2001 Load: 53.5 t ADT: 5

US 59

Good

Over: GREY CREEK

0.3 mi N SR C16, Cherokee, IA

Built 1986 Load: 53.5 t ADT: 1,460

IA 7

Good

Over: MAPLE CREEK

1.2 mi. E of Jct. IA #3, Cherokee, IA

Built 1989 Load: 53.5 t ADT: 2,020

300TH AVENUE

Good

Over: AMES CREEK

081E42104, Clinton, IA

Built 2004 Load: 53.5 t ADT: 536

432ND AVENUE

Good

Over: N BRANCH OF ELK RIVER

083E60304, Clinton, IA

Built 1998 Load: 53.5 t ADT: 73

115TH STREET

Good

Over: ELK RIVER

083E60803, Clinton, IA

Built 1990 Load: 53.5 t ADT: 150

370TH ST

Good

Over: CREEK

087E4, Jackson, IA

Built 2012 Load: 53.5 t ADT: 71

H38 LAMBERT AVE

Good

Over: NISHNABOTNA

072413501, Mills, IA

Built 2012 Load: 53.5 t ADT: 289

JORDAN AVE

Good

Over: STREAM

075323402, Adair, IA

Built 2011 Load: 53.6 t ADT: 35

US 6

Good

Over: LITTLE SILVER CREEK

0.3 MI. W SR L-55, Pottawattamie, IA

Built 1989 Load: 53.6 t ADT: 3,410

230TH ST

Good

Over: BATTLE CREEK

75311020, Adair, IA

Built 2004 Load: 53.7 t ADT: 30

MARION AVE

Good

Over: STREAM

0.8 mi N of G61 on Marion, Adair, IA

Built 2015 Load: 53.8 t ADT: 30

1480 TAFT AVE

Good

Over: EAST IOWA RIVER

094230802, Hancock, IA

Built 2005 Load: 53.8 t ADT: 46

LOCAL

Good

Over: BOYER RIVER

088371601, Sac, IA

Built 1994 Load: 53.8 t ADT: 40

LOCAL

Good

Over: BOYER RIVER

088372801, Sac, IA

Built 2005 Load: 53.8 t ADT: 40

570TH AVE

Good

Over: BALLARD CREEK

570th Ave ov Ballard Cr, Story, IA

Built 2020 Load: 53.8 t ADT: 110

FM

Good

Over: LIZARD CREEK

089300106, Webster, IA

Built 2004 Load: 53.8 t ADT: 549

FISH HATCHERY

Good

Over: STREAM

IN ST. FISH HATCHERY, Delaware, IA

Built 1994 Load: 53.9 t

584TH AVE

Good

Over: SMALL CREEK

084E63602, Jackson, IA

Built 2016 Load: 53.9 t ADT: 30

IA 60 SB

Good

Over: FLOYD RIVER

2.5 mi. N of Jct. US 18, O'Brien, IA

Built 2004 Load: 53.9 t ADT: 2,650

IA 60 NB

Good

Over: FLOYD RIVER

2.5 mi N of Jct US 18, O'Brien, IA

Built 2004 Load: 53.9 t ADT: 2,650

40TH PLACE

Good

Over: STREAM

075212706, Marion, IA

Built 2015 Load: 54.0 t ADT: 41

CHERRYVALLEY RD

Good

Over: SMALL STREAM

091022760, Clayton, IA

Built 2012 Load: 54.1 t ADT: 104

Showing 16,101-16,150 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.