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

240TH ST

Good

Over: CLEAR CREEK

9144141107500, Plymouth, IA

Built 2023 Load: 37.9 t ADT: 26

130TH ST

Good

Over: WOLF CREEK

9345210110, Plymouth, IA

Built 2010 Load: 37.9 t ADT: 45

FM-WHIPPERWILL

Good

Over: WALNUT CREEK

077381101, Pottawattamie, IA

Built 2003 Load: 37.9 t ADT: 79

180TH AVE

Good

Over: CROW CREEK

079E43004, Scott, IA

Built 1992 Load: 37.9 t ADT: 490

SB US 61

Good

Over: CROW CREEK

1.6 MI. N OF JCT. I-80, Scott, IA

Built 1981 Load: 37.9 t ADT: 17,750

LOCAL

Good

Over: BUCK CREEK

079373501, Shelby, IA

Built 1991 Load: 37.9 t ADT: 30

FM

Good

Over: SIX MILE CREEK

095472202, Sioux, IA

Built 1993 Load: 37.9 t ADT: 439

A 18

Good

Over: CREEK

Fremont 24, Winneshiek, IA

Built 2013 Load: 37.9 t ADT: 550

LOCAL

Good

Over: BIG CREEK

0884336, Woodbury, IA

Built 1992 Load: 37.9 t ADT: 15

LOCAL

Good

Over: MUD CREEK

089443001, Woodbury, IA

Built 1991 Load: 37.9 t ADT: 60

LOCAL

Good

Over: SMALL STREAM

090162101, Butler, IA

Built 2007 Load: 38.0 t ADT: 41

270TH ST

Good

Over: SMALL STREAM

091153501, Butler, IA

Built 2019 Load: 38.0 t ADT: 74

OAK AVE

Good

Over: SMALL STREAM

Oak Ave. 1200 S. of C33, Butler, IA

Built 2020 Load: 38.0 t ADT: 35

310TH STREET

Good

Over: SMALL STREAM

090152401, Butler, IA

Built 2002 Load: 38.0 t ADT: 51

IVY AVENUE

Good

Over: SMALL

090170902, Butler, IA

Built 2003 Load: 38.0 t ADT: 5

175TH STREET

Good

Over: SMALL

092151203, Butler, IA

Built 2004 Load: 38.0 t ADT: 41

LOCAL

Good

Over: SMALL STREAM

090181804, Butler, IA

Built 2007 Load: 38.0 t ADT: 30

LOCAL

Good

Over: CREEK

094120902, Chickasaw, IA

Built 2004 Load: 38.0 t ADT: 49

352ND AVE.

Good

Over: BROPHY CREEK

082E50504, Clinton, IA

Built 1996 Load: 38.0 t ADT: 51

FM C-70

Good

Over: FLOYD RIVER

090463007, Plymouth, IA

Built 1990 Load: 38.0 t ADT: 1,487

IRIS AVE

Good

Over: CREEK

9146280210, Plymouth, IA

Built 2010 Load: 38.0 t ADT: 11

DOGWOOD ROAD

Good

Over: LITTLE KEG CREEK

075422803, Pottawattamie, IA

Built 2007 Load: 38.0 t ADT: 26

LOCAL

Good

Over: CREEK

080E32504, Scott, IA

Built 1999 Load: 38.0 t ADT: 34

FM

Good

Over: CHEQUEST CREEK

069111408, Van Buren, IA

Built 1989 Load: 38.0 t ADT: 720

175TH ST

Good

Over: SMALL STREAM

092150803, Butler, IA

Built 2004 Load: 38.1 t ADT: 59

BELLA VISTA DR

Good

Over: LATERAL #77 DD #23

000000000, Carroll, IA

Built 1988 Load: 38.1 t ADT: 293

220TH STREET

Good

Over: CREEK

081E60401, Clinton, IA

Built 1962 Load: 38.1 t ADT: 1,310

FM

Good

Over: BLACK HAWK CREEK

088172802, Grundy, IA

Built 2010 Load: 38.1 t ADT: 20

ENTRY ROAD

Good

Over: WALNUT CREEK

2750' S. OF 96TH AVE., Jasper, IA

Built 1996 Load: 38.1 t ADT: 159

EB/SB IA 163

Good

Over: OVER UP RR

1.1 mi. E of Jct. IA 92, Mahaska, IA

Built 1996 Load: 38.1 t ADT: 3,900

US 30 EB

Good

Over: OVER UP RR

1.0 MILE W OF JCT SR T31, Marshall, IA

Built 1986 Load: 38.1 t ADT: 7,350

LOCAL

Good

Over: LITTLE SILVER CREEK

078401505, Shelby, IA

Built 2000 Load: 38.1 t ADT: 30

FM

Good

Over: SILVER CREEK

079391501, Shelby, IA

Built 2005 Load: 38.1 t ADT: 120

IA 173

Good

Over: INDIAN CREEK

0.5 MI. S OF Jct. IA 44, Audubon, IA

Built 2003 Load: 38.2 t ADT: 1,360

305TH ST

Good

Over: TROUBLESOME CREEK

078340707, Audubon, IA

Built 2021 Load: 38.2 t ADT: 51

140TH ST

Good

Over: CREEK

081362501, Audubon, IA

Built 2013 Load: 38.2 t ADT: 35

110TH ST

Good

Over: LITTLE WAPSIPICON RIVER

093111201, Bremer, IA

Built 2013 Load: 38.2 t ADT: 70

LOCAL

Good

Over: SMALL STREAM

090172301, Butler, IA

Built 1989 Load: 38.2 t ADT: 35

FM

Good

Over: MAYNES CREEK

091181502, Butler, IA

Built 1992 Load: 38.2 t ADT: 579

175TH ST

Good

Over: SMALL STREAM

092150905, Butler, IA

Built 1988 Load: 38.2 t ADT: 34

LOCAL

Good

Over: MILL CREEK

082021406, Cedar, IA

Built 1992 Load: 38.2 t ADT: 130

OLD 21 ROAD

Good

Over: MILL CREEK

092402306, Cherokee, IA

Built 2006 Load: 38.2 t ADT: 120

COUNTY ROAD

Good

Over: BEAVER CREEK

081272301, Dallas, IA

Built 2005 Load: 38.2 t ADT: 26

WILLIS AVE

Good

Over: FROG CREEK

0.2 Miles West of 1st Ave, Dallas, IA

Built 2018 Load: 38.2 t ADT: 2,269

STAGECOACH DR

Good

Over: SUGAR CREEK

City of West Des Moines, Dallas, IA

Built 2017 Load: 38.2 t ADT: 143

MILLVILLE RD

Good

Over: STREAM

089013607, Dubuque, IA

Built 2021 Load: 38.2 t ADT: 59

FM

Good

Over: WEST DES MOINES RIVER

100343408, Emmet, IA

Built 2006 Load: 38.2 t ADT: 709

280TH ST

Good

Over: SKUNK RIVER

087240101, Hamilton, IA

Built 2020 Load: 38.2 t ADT: 34

FM-335TH ST

Good

Over: POTATO CREEK

078423101, Harrison, IA

Built 1993 Load: 38.2 t ADT: 100

FM

Good

Over: CREEK

078110203, Iowa, IA

Built 2000 Load: 38.2 t ADT: 690

Showing 13,651-13,700 of 20,753 bridges

Related

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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.