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

LOC 108TH ST

Good

Over: SMALL STREAM

090090207, Buchanan, IA

Built 1987 Load: 32.4 t ADT: 29

KENTUCKY AVE

Good

Over: SMALL STREAM

090092302, Buchanan, IA

Built 2012 Load: 32.4 t ADT: 41

DEACON AVE

Good

Over: SMALL STREAM

090101002, Buchanan, IA

Built 2015 Load: 32.4 t ADT: 82

DILLON AVE

Good

Over: SMALL STREAM

090102206, Buchanan, IA

Built 2015 Load: 32.4 t ADT: 113

275TH ST

Good

Over: SMALL STREAM

8810321050, Buchanan, IA

Built 2011 Load: 32.4 t ADT: 25

275TH ST

Good

Over: SMALL STREAM

8810319050, Buchanan, IA

Built 2011 Load: 32.4 t ADT: 25

WASHINGTON AVE

Good

Over: SMALL CREEK

8807260065, Buchanan, IA

Built 2013 Load: 32.4 t ADT: 15

180TH ST

Good

Over: MALONE CREEK

T89NR9WS14E25S80, Buchanan, IA

Built 2004 Load: 32.4 t ADT: 11

OVERLAND AVE

Good

Over: DRAINAGE

north of Linn Buchanan in, Buchanan, IA

Built 2015 Load: 32.4 t ADT: 59

RINGOLD AVE

Good

Over: DRAINAGE

.25 mi. north of 335th st, Buchanan, IA

Built 2015 Load: 32.4 t ADT: 73

270TH ST

Good

Over: SMALL STREAM

3540008807, Buchanan, IA

Built 2021 Load: 32.4 t ADT: 15

M50 160TH AVE

Good

Over: UNNAMED CREEK

090360302, Buena Vista, IA

Built 2022 Load: 32.4 t ADT: 249

C25 (480TH ST)

Good

Over: CREEK

092360401, Buena Vista, IA

Built 2014 Load: 32.4 t ADT: 270

C25 (480TH ST)

Good

Over: BRANCH OF MAPLE

092380601, Buena Vista, IA

Built 2014 Load: 32.4 t ADT: 90

510TH ST

Good

Over: MAPLE CREEK

092382001, Buena Vista, IA

Built 2014 Load: 32.4 t ADT: 26

430TH ST

Good

Over: LOCAL STREAM

093370603, Buena Vista, IA

Built 2012 Load: 32.4 t ADT: 45

220TH AVE

Good

Over: DRAINAGEDISTRICTDITCH 1

090352202, Buena Vista, IA

Built 2013 Load: 32.4 t ADT: 11

C49 590TH ST

Good

Over: DRAINAGE DITCH 101

091353201, Buena Vista, IA

Built 2018 Load: 32.4 t ADT: 1,097

T47 SINCLAIR AVE

Good

Over: SMALL STREAM

090162702, Butler, IA

Built 2014 Load: 32.4 t ADT: 960

FOREST AVE

Good

Over: BEAVER CREEK

Forest Ave. N. of Hwy 57, Butler, IA

Built 2018 Load: 32.4 t ADT: 73

C45 BUTLER CNTR

Good

Over: SMALL STREAM

091161701, Butler, IA

Built 2014 Load: 32.4 t ADT: 363

265TH ST

Good

Over: SMALL STREAM

091162803, Butler, IA

Built 2018 Load: 32.4 t ADT: 25

BIRCH AVE

Good

Over: SMALL STREAM

091180502, Butler, IA

Built 2014 Load: 32.4 t ADT: 41

T16 DOUGLAS AVE

Good

Over: HARTGRAVE CREEK

092183402, Butler, IA

Built 2013 Load: 32.4 t ADT: 579

C13 110TH ST

Good

Over: DRY RUN CREEK

093151001, Butler, IA

Built 2014 Load: 32.4 t ADT: 530

130TH ST

Good

Over: FLOOD CREEK

093162301, Butler, IA

Built 2015 Load: 32.4 t ADT: 21

CAMP COMFORT RD

Good

Over: SMALL STREAM

093162701, Butler, IA

Built 2016 Load: 32.4 t ADT: 35

E SOUTH ST

Good

Over: SMALL STREAM

093171201, Butler, IA

Built 2016 Load: 32.4 t ADT: 779

SPRING AVE

Good

Over: UNNAMED WATERWAY

090151802, Butler, IA

Built 2014 Load: 32.4 t ADT: 49

305TH ST

Good

Over: UNNAMED WATERWAY

090161303, Butler, IA

Built 2014 Load: 32.4 t ADT: 35

380TH ST

Good

Over: STREAM

086332501, Calhoun, IA

Built 2021 Load: 32.4 t ADT: 34

D68 390TH ST

Good

Over: BOONE CREEK

086333301, Calhoun, IA

Built 2020 Load: 32.4 t ADT: 30

HARRIS AVE

Good

Over: CAMP CREEK

088342502, Calhoun, IA

Built 2014 Load: 32.4 t ADT: 60

IA 141

Good

Over: UNNAMED STREAM

0.9 mi. W of Jct. SR N44, Carroll, IA

Built 2014 Load: 32.4 t ADT: 1,500

IA 148

Good

Over: WEST NODAWAY RIVER

0.9 mi. S of jct. 92, Cass, IA

Built 2016 Load: 32.4 t ADT: 770

YANKTON RD

Good

Over: STALE BRANCH

074343301, Cass, IA

Built 2017 Load: 32.4 t ADT: 30

G53 TUCSON RD

Good

Over: BR W NODAWAY RIVER

074350901, Cass, IA

Built 2018 Load: 32.4 t ADT: 60

560TH ST

Good

Over: WATERWAY

0743704047, Cass, IA

Built 2015 Load: 32.4 t ADT: 269

740TH ST

Good

Over: NODAWAY RIVER

074343302, Cass, IA

Built 2017 Load: 32.4 t ADT: 72

JACKSON RD

Good

Over: SMALL STREAM

076361303, Cass, IA

Built 2015 Load: 32.4 t ADT: 110

LANSING RD

Good

Over: WATERWAY

076373401, Cass, IA

Built 2018 Load: 32.4 t ADT: 120

LANSING RD

Good

Over: WATERWAY

076373502, Cass, IA

Built 2013 Load: 32.4 t ADT: 120

AKRON RD

Good

Over: WATERWAY

077340201, Cass, IA

Built 2017 Load: 32.4 t ADT: 35

G16 BOSTON RD

Good

Over: SMALL CREEK

077350701, Cass, IA

Built 2021 Load: 32.4 t ADT: 131

IA 130

Good

Over: SUGAR CREEK

2.4 MI E OF JCT Iowa 38, Cedar, IA

Built 2013 Load: 32.4 t ADT: 2,040

205TH ST

Good

Over: ROCK CREEK

081032603, Cedar, IA

Built 2014 Load: 32.4 t ADT: 40

US 65

Good

Over: E BRANCH BEAVER DAM CRK

0.7 mi. S of S.R. B60, Cerro Gordo, IA

Built 2021 Load: 32.4 t ADT: 2,180

US 65

Good

Over: E BRANCH BEAVER DAM CRK

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

Built 2020 Load: 32.4 t ADT: 2,440

285TH ST

Good

Over: SMALL STREAM

0.25 MI E S34, Cerro Gordo, IA

Built 2016 Load: 32.4 t ADT: 135

12TH AVE S

Good

Over: CLEAR CREEK

96211801, Cerro Gordo, IA

Built 2016 Load: 32.4 t ADT: 818

Showing 10,451-10,500 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.