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

EAST WASHINGTON ST

Good

Over: W NODAWAY RIVER

069363205, Page, IA

Built 2018 Load: 32.4 t ADT: 2,091

US 75 SB

Good

Over: STREAM

0.6 mi. S of SR C60, Plymouth, IA

Built 2020 Load: 32.4 t ADT: 7,500

IA 3

Good

Over: W FORK OF FLOYD RIVER

0.7 mi. W of US 75, Plymouth, IA

Built 2004 Load: 32.4 t ADT: 2,070

IA 12

Good

Over: INDIAN CREEK

4.0 mi N of SR C16, Plymouth, IA

Built 2021 Load: 32.4 t ADT: 1,120

160TH ST

Good

Over: FLOYD RIVER

9245040110, Plymouth, IA

Built 2013 Load: 32.4 t ADT: 131

C-38

Good

Over: W BR FLOYD RIVER

9246350120, Plymouth, IA

Built 2012 Load: 32.4 t ADT: 1,347

IA 3

Good

Over: BRANCH 19 OF DD NO 53

0.3 MI. W OF IA 4, Pocahontas, IA

Built 2018 Load: 32.4 t ADT: 2,060

C56 590TH ST

Good

Over: LIZARD CREEK

090320801, Pocahontas, IA

Built 2015 Load: 32.4 t ADT: 240

C26 460TH ST

Good

Over: PILOT CREEK

092310603, Pocahontas, IA

Built 2015 Load: 32.4 t ADT: 270

410TH ST

Good

Over: NO LIZARD CK

093330801, Pocahontas, IA

Built 2019 Load: 32.4 t ADT: 5

190TH AVE

Good

Over: DD 77 N LIZARD CREEK

093331502, Pocahontas, IA

Built 2015 Load: 32.4 t ADT: 30

US 6

Good

Over: FOUR MILE CREEK & TRAIL

1.3 MI. E OF JCT. I-235, Polk, IA

Built 2014 Load: 32.4 t ADT: 14,300

ARMY POST RD

Good

Over: NATURE TRAIL & CK

078243600, Polk, IA

Built 2015 Load: 32.4 t ADT: 121

I 35 SB

Good

Over: IAIS RR

0.2 mi. S of Grand Ave., Polk, IA

Built 2013 Load: 32.4 t ADT: 24,650

I 35 NB

Good

Over: FOUR MILE CREEK

3.1 MILES N OF JCT IA 160, Polk, IA

Built 2018 Load: 32.4 t ADT: 28,400

I 35 SB

Good

Over: FOUR MILE CREEK

3.1 MI. N OF JCT. IA 160, Polk, IA

Built 2020 Load: 32.4 t ADT: 28,400

EVERGREEN AVE

Good

Over: EASTER LAKE

078231900, Polk, IA

Built 2018 Load: 32.4 t ADT: 1,686

NE 54TH ST

Good

Over: BR OF FOUR MI CR

080240103, Polk, IA

Built 2019 Load: 32.4 t ADT: 643

NW 5TH ST

Good

Over: NORTH CREEK

080241600, Polk, IA

Built 2013 Load: 32.4 t ADT: 1,820

NW 2ND ST

Good

Over: MUD CREEK

080233601, Polk, IA

Built 2020 Load: 32.4 t ADT: 2,604

I35 NB OFF RAMP

Good

Over: IAIS RR

0.9 mi. N jct. IA 5, Polk, IA

Built 2014 Load: 32.4 t ADT: 4,330

US 65 NB

Good

Over: DESMOINES RVR S OVERFLOW

1.0 MI N OF SE 64TH AVE, Polk, IA

Built 2013 Load: 32.4 t ADT: 12,450

US 65 SB

Good

Over: DES MOINES RVR MID OVRFW

1.1 MI. N of SE 64th AVE., Polk, IA

Built 2014 Load: 32.4 t ADT: 12,450

IA 28 SB

Good

Over: RACCOON RIVER

3.7 MI. N. OF IA 5, Polk, IA

Built 2022 Load: 32.4 t ADT: 12,600

IA 92 WB

Good

Over: MOSQUITO CREEK & RR

0.4 MI. E OF JCT I-29, Pottawattamie, IA

Built 2015 Load: 32.4 t ADT: 9,800

IA 92

Good

Over: LITTLE SILVER CREEK

0.3 MI. W OF CO. RD. L-55, Pottawattamie, IA

Built 2015 Load: 32.4 t ADT: 4,450

N BROADWAY

Good

Over: INDIAN CREEK

000000000, Pottawattamie, IA

Built 2023 Load: 32.4 t ADT: 5,896

OLD LINCOLN HWY

Good

Over: SIMONS RUN

076441310, Pottawattamie, IA

Built 2017 Load: 32.4 t ADT: 2,430

I 80 WB US 6 WB

Good

Over: INDIAN CREEK

0.7 MI. E OF 24TH ST, Pottawattamie, IA

Built 2017 Load: 32.4 t ADT: 19,400

I 80 US 6 EB

Good

Over: INDIAN CREEK

0.7 MI. E. OF 24TH ST, Pottawattamie, IA

Built 2018 Load: 32.4 t ADT: 19,400

I 29 SB US 6 EB

Good

Over: 9TH AVE

0.6 MI. S OF JCT. U.S. 6, Pottawattamie, IA

Built 2023 Load: 32.4 t ADT: 15,000

HACKBERRY RD

Good

Over: WALNUT CREEK

075382201, Pottawattamie, IA

Built 2018 Load: 32.4 t ADT: 26

HONEYSUCKLE RD

Good

Over: KEG CREEK

075421101, Pottawattamie, IA

Built 2018 Load: 32.4 t ADT: 29

G12 DESOTA AVE

Good

Over: BOYER RIVER

077440407, Pottawattamie, IA

Built 2019 Load: 32.4 t ADT: 409

IA 92 EB

Good

Over: MOSQUITO CREEK & RR

0.3 MI. E OF JCT I-29, Pottawattamie, IA

Built 2016 Load: 32.4 t ADT: 9,800

I 29 SB

Good

Over: INDIAN CREEK

0.7 MI. E OF 24TH ST, Pottawattamie, IA

Built 2018 Load: 32.4 t ADT: 16,200

I 80 EB

Good

Over: UP RR

0.3 MI. E OF IA 146, Poweshiek, IA

Built 2020 Load: 32.4 t ADT: 13,100

V21 (202ND ST)

Good

Over: DEEP RIVER

078130508, Poweshiek, IA

Built 2013 Load: 32.4 t ADT: 80

512TH AVE

Good

Over: BUCK CREEK

078151903, Poweshiek, IA

Built 2015 Load: 32.4 t ADT: 60

110TH ST

Good

Over: LITTLE BEAR CREEK

080152604, Poweshiek, IA

Built 2021 Load: 32.4 t ADT: 26

US 169

Good

Over: MIDDLE FORK GRAND RIVER

5.3 mi. S of S Jct. IA 2, Ringgold, IA

Built 2021 Load: 32.4 t ADT: 500

310TH ST

Good

Over: FLETCHALL CREEK

067302301, Ringgold, IA

Built 2021 Load: 32.4 t ADT: 45

270TH ST

Good

Over: MIDDLE FORK GRAND RIVER

068303501, Ringgold, IA

Built 2020 Load: 32.4 t ADT: 40

200TH STREET

Good

Over: BRUSH CREEK

069302903, Ringgold, IA

Built 2021 Load: 32.4 t ADT: 34

180TH AVE

Good

Over: PLUM CREEK

070300902, Ringgold, IA

Built 2020 Load: 32.4 t ADT: 15

US 20

Good

Over: UNNAMED STREAM

3.7 MI. W OF JCT. US 71, Sac, IA

Built 2017 Load: 32.4 t ADT: 4,850

US 71

Good

Over: CEDAR CREEK

0.1 MI. S OF CO. RD. D36, Sac, IA

Built 2015 Load: 32.4 t ADT: 1,720

320TH ST

Good

Over: INDIAN CREEK

087362701, Sac, IA

Built 2021 Load: 32.4 t ADT: 40

QUINCY AVE

Good

Over: INDIAN CREEK

087362702, Sac, IA

Built 2017 Load: 32.4 t ADT: 139

IRA AVENUE

Good

Over: STREAM

087370502, Sac, IA

Built 2022 Load: 32.4 t ADT: 40

Showing 10,901-10,950 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.