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

100TH AVE

Good

Over: DUCK CREEK

078E21402, Scott, IA

Built 1988 Load: 36.3 t ADT: 25

145TH AVE

Good

Over: CREEK

079E32108, Scott, IA

Built 2000 Load: 36.3 t ADT: 150

210TH AVE

Good

Over: SMALL STREAM

080E41004, Scott, IA

Built 2002 Load: 36.3 t ADT: 80

LOCAL

Good

Over: E BRANCH W. NISHABOTNA

078391303, Shelby, IA

Built 2005 Load: 36.3 t ADT: 34

US 30 WB

Good

Over: EAST INDIAN CREEK

3.4 MILES WEST OF JCT. 65, Story, IA

Built 1997 Load: 36.3 t ADT: 4,750

110TH ST

Good

Over: WEST 102 RIVER

070340701, Taylor, IA

Built 2019 Load: 36.3 t ADT: 20

OSAGE AVE

Good

Over: BIG INDIAN CREEK

068093304, Van Buren, IA

Built 2013 Load: 36.3 t ADT: 51

130TH STREET

Good

Over: LIME CREEK

077082101, Washington, IA

Built 2020 Load: 36.3 t ADT: 80

200TH AVE

Good

Over: WINNEBAGO RIVER

100232804, Winnebago, IA

Built 2015 Load: 36.3 t ADT: 11

LOCAL ROAD

Good

Over: CREEK

097090302, Winneshiek, IA

Built 1998 Load: 36.3 t ADT: 44

LOCAL ROAD

Good

Over: TEN MILE CREEK

098091901, Winneshiek, IA

Built 1984 Load: 36.3 t ADT: 49

130TH ST

Good

Over: STREAM

089432001, Woodbury, IA

Built 2023 Load: 36.3 t ADT: 11

R65 UNION AVE

Good

Over: LUICK CREEK

093233302, Wright, IA

Built 2016 Load: 36.3 t ADT: 406

LOCAL

Good

Over: HINKLE CREEK

085112807, Benton, IA

Built 1989 Load: 36.4 t ADT: 50

W EAGLE ROAD

Good

Over: MILLER CREEK

87-13-20-01-10, Black Hawk, IA

Built 1988 Load: 36.4 t ADT: 471

LOCAL

Good

Over: SMALL

092130901, Bremer, IA

Built 2005 Load: 36.4 t ADT: 39

LOCAL

Good

Over: SMALL STREAM

092351501, Buena Vista, IA

Built 2009 Load: 36.4 t ADT: 15

FM

Good

Over: CAMP CREEK

088343201, Calhoun, IA

Built 1992 Load: 36.4 t ADT: 45

LOCAL

Good

Over: SKUNK RIVER

087242402, Hamilton, IA

Built 1993 Load: 36.4 t ADT: 30

LOCAL

Good

Over: S.FK IOWA RIVER

087202005, Hardin, IA

Built 1990 Load: 36.4 t ADT: 30

US 71

Good

Over: LONG'S BRANCH

1.8 MI. N OF N JCT SR H34, Montgomery, IA

Built 1970 Load: 36.4 t ADT: 1,390

FM

Good

Over: DRY RUN

095412401, O'Brien, IA

Built 2001 Load: 36.4 t ADT: 60

FM

Good

Over: LITTLE FLOYD RIVER

097412902, O'Brien, IA

Built 1992 Load: 36.4 t ADT: 489

FM

Good

Over: WALNUT CREEK

069291601, Ringgold, IA

Built 1991 Load: 36.4 t ADT: 110

SR P54 250TH AV

Good

Over: STREAM

070291002, Ringgold, IA

Built 2011 Load: 36.4 t ADT: 26

200TH ST

Good

Over: EAST BR INDIAN CREEK

084222603, Story, IA

Built 2000 Load: 36.4 t ADT: 40

GILBERTVILLE RD

Good

Over: TRIB TO CEDAR RIVER

88-12-09-04-10, Black Hawk, IA

Built 1988 Load: 36.5 t ADT: 1,206

130TH STREET

Good

Over: SMALL

093151903, Butler, IA

Built 2005 Load: 36.5 t ADT: 35

270TH AVENUE

Good

Over: SMALL STREAM

082E32502, Clinton, IA

Built 1992 Load: 36.5 t ADT: 51

LOCAL

Good

Over: CREEK

084E22305, Jackson, IA

Built 1950 Load: 36.5 t ADT: 20

FM

Good

Over: MAPLE RIVER

084442403, Monona, IA

Built 1957 Load: 36.5 t ADT: 188

FM

Good

Over: SOUTH ENGLISH RIVER

078142002, Poweshiek, IA

Built 2002 Load: 36.5 t ADT: 30

US 75

Good

Over: W FORK FLOYD RIVER

0.1 mi N of Jct. IA 10, Sioux, IA

Built 1989 Load: 36.5 t ADT: 7,300

IA 12

Good

Over: DRY CREEK

0.4 mi. S of IA 10, Sioux, IA

Built 1963 Load: 36.5 t ADT: 2,750

564TH AVE

Good

Over: WALNUT CREEK

082230606, Story, IA

Built 1995 Load: 36.5 t ADT: 71

60TH AVE

Good

Over: JORDAN CREEK

072121702, Wapello, IA

Built 2021 Load: 36.5 t ADT: 21

300TH ST

Good

Over: STREAM

74321810, Adair, IA

Built 2012 Load: 36.6 t ADT: 46

ORANGE AVE

Good

Over: STREAM

1 mi S of 92 on Orange Av, Adair, IA

Built 2014 Load: 36.6 t ADT: 21

LOCAL

Good

Over: MIDDLE NODAWAY RIVER

075330403, Adair, IA

Built 1998 Load: 36.6 t ADT: 72

P25 (RIVERSIDE)

Good

Over: MIDDLE RIVER, BRANCH

76311309, Adair, IA

Built 2012 Load: 36.6 t ADT: 34

180TH ST

Good

Over: NINE MILE CREEK

1.1 mi W of N72 on 180th, Adair, IA

Built 2014 Load: 36.6 t ADT: 21

ELK AVE

Good

Over: BRANCH NODAWAY RIVER

77332609, Adair, IA

Built 2012 Load: 36.6 t ADT: 30

BETHEL RD

Good

Over: WILLIAMS CREEK

T96N R06W S23NW, Allamakee, IA

Built 2015 Load: 36.6 t ADT: 44

MAKEE DRIVE

Good

Over: VILLAGE CREEK

098052801, Allamakee, IA

Built 2022 Load: 36.6 t ADT: 157

LOCAL

Good

Over: UPPER IOWA RIVER

100042802, Allamakee, IA

Built 1991 Load: 36.6 t ADT: 70

470TH ST

Good

Over: WALNUT & WOLF BRANCH

069180701, Appanoose, IA

Built 2018 Load: 36.6 t ADT: 50

FM F-65

Good

Over: TROUBLESOME CR

078353505, Audubon, IA

Built 1989 Load: 36.6 t ADT: 34

NB I-380

Good

Over: INDIAN CREEK

2.1 MI. S OF JCT. 20, Black Hawk, IA

Built 1984 Load: 36.6 t ADT: 8,450

310TH ST

Good

Over: SMALL STREAM

087082001, Buchanan, IA

Built 2019 Load: 36.6 t ADT: 44

LOCAL RD 540TH

Good

Over: CREEK

091350601, Buena Vista, IA

Built 2002 Load: 36.6 t ADT: 20

Showing 13,201-13,250 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.