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

D68 390TH ST

Good

Over: BUTTRICK CREEK

086303301, Webster, IA

Built 2015 Load: 32.4 t ADT: 50

300TH ST

Good

Over: HARDIN CREEK

087301801, Webster, IA

Built 2013 Load: 32.4 t ADT: 41

220TH ST

Good

Over: DD

088270506, Webster, IA

Built 2019 Load: 32.4 t ADT: 50

15TH AVE S

Good

Over: DD #1

089283303, Webster, IA

Built 2018 Load: 32.4 t ADT: 1,875

PARAGON AVE

Good

Over: GYPSUM MINE HAUL RD

089283404, Webster, IA

Built 2017 Load: 32.4 t ADT: 1,755

N 1ST ST

Good

Over: SOLDIER CREEK

089281800, Webster, IA

Built 2019 Load: 32.4 t ADT: 961

160TH AVE

Good

Over: PIKE RUN

099241402, Winnebago, IA

Built 2022 Load: 32.4 t ADT: 30

WEST RAVINE RD

Good

Over: UPPER IOWA RIVER

0000, Winneshiek, IA

Built 2011 Load: 32.4 t ADT: 49

US 20 EB

Good

Over: W FK LITTLE SIOUX RIVER

0.1 Mi West of IA 140, Woodbury, IA

Built 2015 Load: 32.4 t ADT: 4,600

US 20 EB

Good

Over: WOLF CREEK

5.2 Miles East of Jct 140, Woodbury, IA

Built 2018 Load: 32.4 t ADT: 3,250

IA 141

Good

Over: GARRETSON DITCH

6.4 MI. E OF I-29, Woodbury, IA

Built 2018 Load: 32.4 t ADT: 2,130

280TH ST

Good

Over: STREAM

086420501, Woodbury, IA

Built 2016 Load: 32.4 t ADT: 5

330TH ST

Good

Over: STREAM

086432605, Woodbury, IA

Built 2017 Load: 32.4 t ADT: 5

D53 280TH ST

Good

Over: DRAINAGE DITCH GARRETSON

086450601, Woodbury, IA

Built 2016 Load: 32.4 t ADT: 30

320TH ST

Good

Over: WOLF CREEK

086452701, Woodbury, IA

Built 2019 Load: 32.4 t ADT: 5

FM

Good

Over: WOLF CREEK

0874501, Woodbury, IA

Built 2010 Load: 32.4 t ADT: 399

POCAHONTAS AVE

Good

Over: BACON CREEK

0884205, Woodbury, IA

Built 2014 Load: 32.4 t ADT: 34

L43 UNION AVE

Good

Over: CREEK

088412404, Woodbury, IA

Built 2017 Load: 32.4 t ADT: 50

MICHIGAN AVE

Good

Over: STREAM

088431104, Woodbury, IA

Built 2012 Load: 32.4 t ADT: 15

MASON AVE

Good

Over: LITTLE SIOUX RIVER

088432107, Woodbury, IA

Built 2021 Load: 32.4 t ADT: 20

WALNUT ST

Good

Over: ELLIOTT CREEK

088462801, Woodbury, IA

Built 2014 Load: 32.4 t ADT: 450

120TH ST

Good

Over: ELLIOTT CREEK

089451601, Woodbury, IA

Built 2017 Load: 32.4 t ADT: 15

150TH ST

Good

Over: ELLIOT CREEK

089453201, Woodbury, IA

Built 2019 Load: 32.4 t ADT: 210

CORRECTIONVILLE RD

Good

Over: WHISKEY CREEK

089463500, Woodbury, IA

Built 2023 Load: 32.4 t ADT: 210

W 23RD ST

Good

Over: PERRY CREEK

000000000, Woodbury, IA

Built 2011 Load: 32.4 t ADT: 283

3RD ST

Good

Over: PERRY CREEK CONDUIT

N OF Jct. I-29 & US77, Woodbury, IA

Built 2013 Load: 32.4 t ADT: 7,065

I29 NB OFF RAMP

Good

Over: PERRY CREEK CONDUIT

0.1 mi S of jct US 77, Woodbury, IA

Built 2017 Load: 32.4 t ADT: 91,000

I 29 SB RAMP

Good

Over: PERRY CREEK CONDUIT

Wesley Pkwy. Ramp C, Woodbury, IA

Built 2019 Load: 32.4 t ADT: 6,200

US 20 WB

Good

Over: WOLF CREEK

5.2 Miles East of Jct 140, Woodbury, IA

Built 2015 Load: 32.4 t ADT: 3,250

I 29 IA 12 NB

Good

Over: PERRY CREEK CONDUIT

0.1 mi S of jct US 77, Woodbury, IA

Built 2017 Load: 32.4 t ADT: 16,450

OLIVE AVE

Good

Over: DRAINAGE DITCH

0.4 Mi S A39, Worth, IA

Built 2017 Load: 32.4 t ADT: 16

S56 THRUSH AVE

Good

Over: STREAM

.7 MI S OF A27, Worth, IA

Built 2015 Load: 32.4 t ADT: 373

MALLARD AVE

Good

Over: GOOSE CREEK

0.7 Mi N Marks Hill Rd, Worth, IA

Built 2016 Load: 32.4 t ADT: 91

US 69

Good

Over: IOWA RIVER

1.1 mi. N of jct. SR C25, Wright, IA

Built 2014 Load: 32.4 t ADT: 2,970

295TH ST

Good

Over: DRAINAGE DITCH #7

090231103, Wright, IA

Built 2012 Load: 32.4 t ADT: 11

YOUNGBLOOD AVE

Good

Over: DD #29

090232404, Wright, IA

Built 2018 Load: 32.4 t ADT: 41

C70 330TH ST

Good

Over: WHITE FOX CREEK

090253501, Wright, IA

Built 2014 Load: 32.4 t ADT: 1,168

BAXTER AVE

Good

Over: DRAINAGE DITCH

090261804, Wright, IA

Built 2011 Load: 32.4 t ADT: 21

250TH ST

Good

Over: EAGLE CREEK

091252101, Wright, IA

Built 2017 Load: 32.4 t ADT: 31

CALHOUN AVE

Good

Over: STREAM

091261606, Wright, IA

Built 2015 Load: 32.4 t ADT: 71

BUCHANAN AVE

Good

Over: STREAM

091263204, Wright, IA

Built 2021 Load: 32.4 t ADT: 35

UPTAGRAPH AVENUE

Good

Over: STREAM

092232702, Wright, IA

Built 2014 Load: 32.4 t ADT: 11

C26 150TH ST

Good

Over: DRAINAGE DITCH 107

093253201, Wright, IA

Built 2015 Load: 32.4 t ADT: 40

C26 (150TH ST)

Good

Over: EAGLE CREEK DD 36

093253601, Wright, IA

Built 2014 Load: 32.4 t ADT: 41

LOCAL

Good

Over: RACCOON RIVER

090362503, Buena Vista, IA

Built 1987 Load: 32.5 t ADT: 45

FM

Good

Over: DIXON BRANCH

084330302, Carroll, IA

Built 1989 Load: 32.5 t ADT: 50

HERON RD.

Good

Over: VOLGA RIVER

093081306, Fayette, IA

Built 1979 Load: 32.5 t ADT: 34

US 34

Good

Over: SILVER CREEK

1.3 mi. W of Jct. SR L-63, Mills, IA

Built 1965 Load: 32.5 t ADT: 6,000

IA 9

Good

Over: DRY RUN CREEK

3.0 mi. E of E jct SR L58, Osceola, IA

Built 1978 Load: 32.5 t ADT: 2,680

IA 130

Good

Over: MUD CREEK

0.5 mi. W of Jct. SR Y40, Scott, IA

Built 1977 Load: 32.5 t ADT: 800

Showing 11,051-11,100 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.