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

LOCAL

Good

Over: BITTER CREEK

089411604, Ida, IA

Built 2004 Load: 34.0 t ADT: 15

MAHOGANY AVE

Good

Over: DRAINAGE

072090604, Jefferson, IA

Built 2017 Load: 34.0 t ADT: 70

LOCAL

Good

Over: BR LITTLE WHITEBREAST

072210403, Lucas, IA

Built 2002 Load: 34.0 t ADT: 26

HEDGE AVE

Good

Over: PERRY CREEK

9147250210, Plymouth, IA

Built 2014 Load: 34.0 t ADT: 30

NE 3RD ST

Good

Over: CREEK

0.13 Mi. N. of NE 6 Ave., Polk, IA

Built 2020 Load: 34.0 t ADT: 2,521

NE 118TH AVE

Good

Over: BRANCH SKUNK RIVER

080220301, Polk, IA

Built 2000 Load: 34.0 t ADT: 45

NW 134TH AVE

Good

Over: FOUR MILE CREEK

0.2 mi E of NW 2nd St, Polk, IA

Built 2021 Load: 34.0 t ADT: 180

142ND ST

Good

Over: WALNUT CREEK

O57000543, Polk, IA

Built 2006 Load: 34.0 t ADT: 3,538

G30 PINOAK RD

Good

Over: SILVER CREEK

076411201, Pottawattamie, IA

Built 2014 Load: 34.0 t ADT: 219

BETTIN AVE

Good

Over: STREAM

089380402, Sac, IA

Built 2017 Load: 34.0 t ADT: 5

L14 KINGBIRD AVE

Good

Over: NO NAME CREEK

096431802, Sioux, IA

Built 2016 Load: 34.0 t ADT: 578

FM

Good

Over: NO NAME CREEK

097431101, Sioux, IA

Built 1965 Load: 34.0 t ADT: 609

LOCAL

Good

Over: SMALL

094471802, Sioux, IA

Built 1960 Load: 34.0 t ADT: 11

LILY AVE

Good

Over: SMALL

096432202, Sioux, IA

Built 2008 Load: 34.0 t ADT: 270

KINGBIRD AVE

Good

Over: SMALL

096433002, Sioux, IA

Built 2010 Load: 34.0 t ADT: 578

E63 305TH ST

Good

Over: CALAMUS CREEK

0.3 Mi E S14, Story, IA

Built 2016 Load: 34.0 t ADT: 90

FM

Good

Over: LITTLE CEDAR CREEK

069080302, Van Buren, IA

Built 1993 Load: 34.0 t ADT: 420

110TH AVE

Good

Over: LITTLE CEDAR CREEK

072130402, Wapello, IA

Built 2017 Load: 34.0 t ADT: 47

307TH AVE

Good

Over: CREEK

0.5 MI S of 240 St., Winneshiek, IA

Built 2019 Load: 34.0 t ADT: 50

200TH ST

Good

Over: STREAM

088422501, Woodbury, IA

Built 2018 Load: 34.0 t ADT: 15

WALNUT ST

Good

Over: CREEK

088462901, Woodbury, IA

Built 2014 Load: 34.0 t ADT: 450

IA 376 RAMP

Good

Over: DRAINAGE

0.1 mi. N of SR D12, Woodbury, IA

Built 2001 Load: 34.0 t ADT: 1,560

FM

Good

Over: MIDDLE NODAWAY RIVER

074332460, Adair, IA

Built 1978 Load: 34.1 t ADT: 249

NB I-380

Good

Over: BEAR CREEK

1.1 MI. S OF JCT. SR D48, Buchanan, IA

Built 1984 Load: 34.1 t ADT: 8,950

WARBLER

Good

Over: BEAVER CREEK

095192302, Cerro Gordo, IA

Built 1990 Load: 34.1 t ADT: 26

180 ST

Good

Over: DRAINAGE DITCH

082E11601, Clinton, IA

Built 2000 Load: 34.1 t ADT: 350

130TH ST.

Good

Over: SMALL

083E62301, Clinton, IA

Built 1993 Load: 34.1 t ADT: 25

FM GENEVA PLACE

Good

Over: SOLDIER RIVER

081442705, Harrison, IA

Built 1980 Load: 34.1 t ADT: 50

LOC 40TH AVE

Good

Over: BLACK CAT CREEK

097302202, Kossuth, IA

Built 1986 Load: 34.1 t ADT: 26

NB I-380

Good

Over: EAST BLUE CREEK

2.3 mi. N of Jct. SR W35, Linn, IA

Built 1982 Load: 34.1 t ADT: 10,750

LOCAL

Good

Over: FLOYD RIVER

097411102, O'Brien, IA

Built 1986 Load: 34.1 t ADT: 50

NATURE AVE

Good

Over: BIG WHISKEY CREEK

091451302, Plymouth, IA

Built 1995 Load: 34.1 t ADT: 11

420TH AVE

Good

Over: BR NORTH ENGLISH RIVER

079160101, Poweshiek, IA

Built 2023 Load: 34.1 t ADT: 30

400TH AVE

Good

Over: STREAM

080163001, Poweshiek, IA

Built 2020 Load: 34.1 t ADT: 100

LOCAL

Good

Over: SM STREAM

097461201, Sioux, IA

Built 1931 Load: 34.1 t ADT: 61

G AVE

Good

Over: ABES FORK

082153102, Tama, IA

Built 2016 Load: 34.1 t ADT: 15

LOCAL

Good

Over: BATTLE CREEK

075300602, Adair, IA

Built 2005 Load: 34.2 t ADT: 26

133TH AVE

Good

Over: SHORT CREEK

071273304, Clarke, IA

Built 2022 Load: 34.2 t ADT: 11

170TH AVE

Good

Over: LOCAL CREEK

073262902, Clarke, IA

Built 2015 Load: 34.2 t ADT: 50

US 67

Good

Over: MC CARTY CREEK

2.8 mi. N of Jct. I-80, Scott, IA

Built 1974 Load: 34.2 t ADT: 3,330

FM

Good

Over: MIDDLE NODAWAY RIVER

076320401, Adair, IA

Built 2002 Load: 34.3 t ADT: 89

330TH ST

Good

Over: LOCAL STREAM

0.1 mi W of P33 on 330th, Adair, IA

Built 2017 Load: 34.3 t ADT: 26

H34 HULL ST

Good

Over: STREAM

072343400, Adams, IA

Built 2022 Load: 34.3 t ADT: 875

F58 LITTLEFIELD DR

Good

Over: DRAINAGE DITCH

0.3 mile W. of Eagle Ave., Audubon, IA

Built 2015 Load: 34.3 t ADT: 597

V56 19 AVE

Good

Over: PRAIRIE CREEK

083111502, Benton, IA

Built 2021 Load: 34.3 t ADT: 88

W REINBECK RD

Good

Over: ROCK CREEK

87-14-25-01-10, Black Hawk, IA

Built 1998 Load: 34.3 t ADT: 39

W CEDAR-WAPSI RD

Good

Over: CEDAR RIVER

90-14-16-05-10, Black Hawk, IA

Built 2020 Load: 34.3 t ADT: 1,178

E26 170TH ST

Good

Over: BEAVER CREEK

084280901, Boone, IA

Built 2016 Load: 34.3 t ADT: 359

LOCAL

Good

Over: BUFFALO CREEK

087071202, Buchanan, IA

Built 2005 Load: 34.3 t ADT: 30

LOCAL

Good

Over: BR RACCOON RIVER

090362602, Buena Vista, IA

Built 1998 Load: 34.3 t ADT: 26

Showing 12,601-12,650 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.