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: SMALL STREAM

091160202, Butler, IA

Built 1997 Load: 29.9 t ADT: 30

LOCAL

Good

Over: SMALL STREAM

091160401, Butler, IA

Built 2004 Load: 29.9 t ADT: 31

LOCAL

Good

Over: SMALL STREAM

091161304, Butler, IA

Built 1999 Load: 29.9 t ADT: 45

230TH ST

Good

Over: SMALL STREAM

2590' east of Ivy Avenue, Butler, IA

Built 2023 Load: 29.9 t ADT: 44

270TH ST

Good

Over: SMALL STREAM

091183301, Butler, IA

Built 2019 Load: 29.9 t ADT: 25

160TH ST

Good

Over: SMALL STREAM

1580' E. of Willow Ave., Butler, IA

Built 2022 Load: 29.9 t ADT: 41

175TH ST

Good

Over: SMALL STREAM

2450' E. of Yale Ave., Butler, IA

Built 2022 Load: 29.9 t ADT: 41

180TH ST

Good

Over: SMALL STREAM

1260' E. of Yale Ave., Butler, IA

Built 2022 Load: 29.9 t ADT: 16

180TH ST

Good

Over: SMALL STREAM

390' W. of Yale Ave., Butler, IA

Built 2022 Load: 29.9 t ADT: 11

WALNUT AVE

Good

Over: STREAM

092153507, Butler, IA

Built 2002 Load: 29.9 t ADT: 113

NEWELL AVE.

Good

Over: SMALL STREAM

092160802, Butler, IA

Built 2006 Load: 29.9 t ADT: 39

OAK AVE

Good

Over: ALRY RUN CREEK

Oak Ave. N. of 185th St., Butler, IA

Built 2020 Load: 29.9 t ADT: 35

MARSH AVE

Good

Over: SMALL STREAM

Marsh Ave. 740' S. of 185, Butler, IA

Built 2023 Load: 29.9 t ADT: 79

230TH ST

Good

Over: KILSON CREEK

230th 3250' E Jackson Ave, Butler, IA

Built 2023 Load: 29.9 t ADT: 15

FLOYD LINE ST

Good

Over: STREAM

093150101, Butler, IA

Built 2019 Load: 29.9 t ADT: 39

VAIL AVE

Good

Over: SMALL STREAM

2190' S. of C13, Butler, IA

Built 2022 Load: 29.9 t ADT: 20

FLOYD LINE ST

Good

Over: STREAM

093160101 2000 W. of T64, Butler, IA

Built 2019 Load: 29.9 t ADT: 15

120TH ST

Good

Over: STREAM

093171501, Butler, IA

Built 2020 Load: 29.9 t ADT: 26

MARSH AVENUE

Good

Over: SMALL

093163102, Butler, IA

Built 2005 Load: 29.9 t ADT: 26

M68 DELTA AVE

Good

Over: FIELD STREAM

083362202, Carroll, IA

Built 2011 Load: 29.9 t ADT: 863

LOCAL

Good

Over: CREEK

097112801, Chickasaw, IA

Built 2005 Load: 29.9 t ADT: 51

LOCAL

Good

Over: CREEK

097112902, Chickasaw, IA

Built 2005 Load: 29.9 t ADT: 30

LOCAL 221 ST

Good

Over: SPRING BRANCH

088050203, Delaware, IA

Built 1982 Load: 29.9 t ADT: 137

260TH AVE

Good

Over: PLUM CREEK

089041402, Delaware, IA

Built 1981 Load: 29.9 t ADT: 20

LOCAL

Good

Over: BEAVER CREEK

095182002, Floyd, IA

Built 2002 Load: 29.9 t ADT: 70

LOCAL ROAD

Good

Over: WOLF CREEK

086173302, Grundy, IA

Built 1978 Load: 29.9 t ADT: 70

LOCAL

Good

Over: SOUTH FORK OF BEAVER CK

088180902, Grundy, IA

Built 1984 Load: 29.9 t ADT: 78

380TH

Good

Over: ROCK

098181601, Mitchell, IA

Built 1970 Load: 29.9 t ADT: 177

500TH

Good

Over: WAPSIPINICON RIVER

100151801, Mitchell, IA

Built 1977 Load: 29.9 t ADT: 70

IA 92

Good

Over: KEG CREEK

2.4 mi W of W Jct. SR L55, Pottawattamie, IA

Built 2008 Load: 29.9 t ADT: 4,450

IA 92

Good

Over: MIDDLE RIVER

0.3 MILE EAST OF IA 28, Warren, IA

Built 1982 Load: 29.9 t ADT: 4,160

IA 5

Good

Over: BUTCHER CREEK

0.7 MI. N OF SR G24, Warren, IA

Built 2001 Load: 29.9 t ADT: 9,100

160TH ST

Good

Over: CREEK

0.5 M. E. of Nighhawk Ave, Audubon, IA

Built 2016 Load: 30.0 t ADT: 15

FM

Good

Over: SMALL STREAM

083383602, Crawford, IA

Built 1975 Load: 30.0 t ADT: 50

FM SPRUCE AVE

Good

Over: SPRING CREEK

092193004, Franklin, IA

Built 1975 Load: 30.0 t ADT: 88

FM

Good

Over: OTTER CREEK

074033006, Louisa, IA

Built 1977 Load: 30.0 t ADT: 60

FM

Good

Over: MILL CREEK

096413402, O'Brien, IA

Built 1971 Load: 30.0 t ADT: 459

FM

Good

Over: DRAINAGE

090432904, Plymouth, IA

Built 1972 Load: 30.0 t ADT: 748

FM C-44

Good

Over: MINNIE BROOK

091450901, Plymouth, IA

Built 1977 Load: 30.0 t ADT: 339

FM

Good

Over: SMALL

093473502, Plymouth, IA

Built 1978 Load: 30.0 t ADT: 878

FM

Good

Over: WILLOW CR

094431702, Sioux, IA

Built 1973 Load: 30.0 t ADT: 722

FM

Good

Over: SPRING CREEK

094470202, Sioux, IA

Built 1974 Load: 30.0 t ADT: 748

FM

Good

Over: NO NAME CREEK

096471702, Sioux, IA

Built 1971 Load: 30.0 t ADT: 718

US 169

Good

Over: BNSF RR

0.2 MI. S OF S JCT. US 34, Union, IA

Built 1980 Load: 30.0 t ADT: 3,870

IA 2

Good

Over: SOUTH CHARITON RIVER

1.6 MI. W OF Jct. SR S26, Wayne, IA

Built 1971 Load: 30.0 t ADT: 1,260

400TH

Good

Over: SHELLROCK RIVER

098200103, Worth, IA

Built 1958 Load: 30.0 t ADT: 47

IA 281

Good

Over: BUCK CREEK

0.6 MI. W OF W JCT SR V62, Black Hawk, IA

Built 1967 Load: 30.1 t ADT: 1,240

LOCAL

Good

Over: SMALL STREAM

911704, Butler, IA

Built 2009 Load: 30.1 t ADT: 51

IA 48

Good

Over: DRAINAGE DITCH

0.8 mi. N of Jct. IA #92, Cass, IA

Built 1985 Load: 30.1 t ADT: 1,490

258TH ST

Good

Over: DRY MILL CREEK

093041906, Clayton, IA

Built 2008 Load: 30.1 t ADT: 10

Showing 10,051-10,100 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.