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

FM

Good

Over: STREAM

076111101, Keokuk, IA

Built 2010 Load: 32.4 t ADT: 45

180TH ST

Good

Over: UNNAMED STREAM

076121302, Keokuk, IA

Built 2016 Load: 32.4 t ADT: 30

G29 170TH ST

Good

Over: COAL CREEK

076130903, Keokuk, IA

Built 2015 Load: 32.4 t ADT: 370

G29 170TH ST

Good

Over: STREAM

076131100, Keokuk, IA

Built 2019 Load: 32.4 t ADT: 71

195TH ST

Good

Over: COAL CREEK

076132303, Keokuk, IA

Built 2017 Load: 32.4 t ADT: 40

150TH AVE

Good

Over: COAL CREEK

076132502, Keokuk, IA

Built 2017 Load: 32.4 t ADT: 26

318TH AVE

Good

Over: S FORK ENGLISH RIVER

077101504, Keokuk, IA

Built 2014 Load: 32.4 t ADT: 80

W15 330TH AVE

Good

Over: STREAM

077102404, Keokuk, IA

Built 2015 Load: 32.4 t ADT: 500

V44 190TH AVE

Good

Over: S FORK ENGLISH RIVER

077121504, Keokuk, IA

Built 2021 Load: 32.4 t ADT: 460

180TH AVE

Good

Over: SOUTH FORK ENGLISH RIVER

077121602, Keokuk, IA

Built 2019 Load: 32.4 t ADT: 90

US 169

Good

Over: BLACK CAT CREEK

4.2 MI. N. OF US 18, Kossuth, IA

Built 2022 Load: 32.4 t ADT: 2,570

105TH ST

Good

Over: HINE CREEK

094293203, Kossuth, IA

Built 2014 Load: 32.4 t ADT: 30

B46 190TH ST

Good

Over: PRAIRIE CREEK

095272201, Kossuth, IA

Built 2017 Load: 32.4 t ADT: 240

B40 210TH ST

Good

Over: LOTTS CREEK

095300901, Kossuth, IA

Built 2017 Load: 32.4 t ADT: 938

220TH AVE

Good

Over: PLUM CREEK

096271002, Kossuth, IA

Built 2015 Load: 32.4 t ADT: 21

260TH AVE

Good

Over: PLUM CREEK

096271601, Kossuth, IA

Built 2015 Load: 32.4 t ADT: 5

P30 90TH AVE

Good

Over: CALAMUS CREEK

096290402, Kossuth, IA

Built 2015 Load: 32.4 t ADT: 339

B 19 (300TH ST)

Good

Over: E FORK DES MOINES RIVER

097282901, Kossuth, IA

Built 2014 Load: 32.4 t ADT: 290

300TH ST

Good

Over: CALAMUS CREEK

097292901, Kossuth, IA

Built 2014 Load: 32.4 t ADT: 50

P30 90TH AVE

Good

Over: CALAMUS CREEK

097293302, Kossuth, IA

Built 2016 Load: 32.4 t ADT: 339

P30 90TH AVE

Good

Over: CALAMUS CREEK

097293302, Kossuth, IA

Built 2018 Load: 32.4 t ADT: 339

A16 500TH ST

Good

Over: UNION SLOUGH DITCH

100281501, Kossuth, IA

Built 2017 Load: 32.4 t ADT: 150

P50 150TH AVE

Good

Over: W BR BLUE EARTH RIVER

100282102, Kossuth, IA

Built 2016 Load: 32.4 t ADT: 159

ABEL ROAD

Good

Over: SUGAR CREEK

1.2 mi E of 160th Ave, Lee, IA

Built 2019 Load: 32.4 t ADT: 60

US 151 NB

Good

Over: CRAB APPLE CREEK

2.9 MI. N OF N JCT. IA 13, Linn, IA

Built 2021 Load: 32.4 t ADT: 7,000

US 151

Good

Over: PRAIRIE CREEK

3 mi. S of US 30 JCT., Linn, IA

Built 2021 Load: 32.4 t ADT: 7,800

SHAVER RD NE

Good

Over: MCCLOUD RUN

083071600, Linn, IA

Built 2023 Load: 32.4 t ADT: 2,450

IA 100

Good

Over: CEDAR RIVER & IANR RR

1.7 Mi. NE of E36, Linn, IA

Built 2016 Load: 32.4 t ADT: 11,500

US 30 WB

Good

Over: SPRING CREEK

3 Mi E of US30/IA1 INTCHG, Linn, IA

Built 2019 Load: 32.4 t ADT: 5,400

US 30 EB

Good

Over: SPRING CREEK

3 Mi E of US30/IA1 INTCHG, Linn, IA

Built 2019 Load: 32.4 t ADT: 5,400

IA 100 EB

Good

Over: MORGAN CREEK

0.1 mi N of SR E48 INTCHG, Linn, IA

Built 2016 Load: 32.4 t ADT: 1,640

IA 100 WB

Good

Over: MORGAN CREEK

0.1 MI N of SR E48 INTCHG, Linn, IA

Built 2016 Load: 32.4 t ADT: 1,640

IA 100 WB OFF RAMP

Good

Over: MORGAN CREEK

IA100 WB & SR E48 INTCHG, Linn, IA

Built 2016 Load: 32.4 t ADT: 1,530

IA 100 EB ON RAMP

Good

Over: MORGAN CREEK

IA100 EB & SR E48 INTCHG, Linn, IA

Built 2016 Load: 32.4 t ADT: 1,440

E 48 E AVE

Good

Over: MORGAN CREEK

IA100 & SR E48 INTCHG, Linn, IA

Built 2016 Load: 32.4 t ADT: 304

IA 1

Good

Over: ABBE CREEK

3.1 MI. N U.S. 30, Linn, IA

Built 2016 Load: 32.4 t ADT: 4,570

X 99 FRANKLIN ST

Good

Over: IOWA RIVER

74032703, Louisa, IA

Built 2020 Load: 32.4 t ADT: 880

65TH ST

Good

Over: STREAM

073030503, Louisa, IA

Built 2020 Load: 32.4 t ADT: 40

X 27 S AVE

Good

Over: SMALL STREAM

073043202, Louisa, IA

Built 2020 Load: 32.4 t ADT: 30

218TH AVE

Good

Over: JOHNNY CREEK

074040404, Louisa, IA

Built 2020 Load: 32.4 t ADT: 180

W66

Good

Over: BIG SLOUGH CREEK

074050804, Louisa, IA

Built 2021 Load: 32.4 t ADT: 190

X 17

Good

Over: BUFFINGTON CREEK

074051412, Louisa, IA

Built 2014 Load: 32.4 t ADT: 290

US 61 SB IA 92 WB

Good

Over: DME RR

3.4 mi. N of W Jct. IA 92, Louisa, IA

Built 2016 Load: 32.4 t ADT: 3,350

US 34

Good

Over: WHITE BREAST CREEK

1.6 MI. E OF E JCT US 65, Lucas, IA

Built 2017 Load: 32.4 t ADT: 3,330

270TH AVE

Good

Over: CHARITON RIVER

071212402, Lucas, IA

Built 2019 Load: 32.4 t ADT: 40

250TH AVE

Good

Over: BR OF ENGLISH CREEK

073211502, Lucas, IA

Built 2017 Load: 32.4 t ADT: 35

130TH TRAIL

Good

Over: S OTTER CREEK

073232208, Lucas, IA

Built 2017 Load: 32.4 t ADT: 26

A34 210TH AVE

Good

Over: WILLOW CREEK

098450601, Lyon, IA

Built 2017 Load: 32.4 t ADT: 578

A34 210TH ST

Good

Over: LITTLE ROCK RIVER

098430501, Lyon, IA

Built 2015 Load: 32.4 t ADT: 718

220TH ST

Good

Over: WEST RAT CREEK

098431101, Lyon, IA

Built 2014 Load: 32.4 t ADT: 30

Showing 10,751-10,800 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.