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: SHOAL CREEK

068182206, Appanoose, IA

Built 1987 Load: 29.8 t ADT: 120

LOCAL

Good

Over: MUD CREEK

084110802, Benton, IA

Built 1999 Load: 29.8 t ADT: 11

BURTON AVE

Good

Over: TRIB QUARTER SECTION RUN

90-13-02-02-10, Black Hawk, IA

Built 2000 Load: 29.8 t ADT: 33

US 20

Good

Over: DRY RUN CREEK

0.3 MI. W OF JCT. IA 58, Black Hawk, IA

Built 1985 Load: 29.8 t ADT: 12,700

US 169

Good

Over: MIDDLE BEAVER CREEK

1.5 MI N OF W JCT US 30, Boone, IA

Built 1932 Load: 29.8 t ADT: 1,890

KILLDEER AV

Good

Over: CRAINS CR

093131402, Bremer, IA

Built 2009 Load: 29.8 t ADT: 20

LOCAL

Good

Over: STREAM

093172304, Butler, IA

Built 2002 Load: 29.8 t ADT: 39

LOCAL

Good

Over: SMALL STREAM

093182901, Butler, IA

Built 2003 Load: 29.8 t ADT: 15

110TH AVE

Good

Over: LOCAL CREEK

072272002, Clarke, IA

Built 2016 Load: 29.8 t ADT: 20

FAWN HOLLOW

Good

Over: ROBERT'S CREEK

094053606, Clayton, IA

Built 1984 Load: 29.8 t ADT: 128

FM

Good

Over: PICAYNE CREEK

083381202, Crawford, IA

Built 1981 Load: 29.8 t ADT: 50

FM

Good

Over: MOSQUITO CREEK

080292001, Dallas, IA

Built 1986 Load: 29.8 t ADT: 79

BEECHWOOD AVE

Good

Over: CREEK

069151704, Davis, IA

Built 2019 Load: 29.8 t ADT: 20

ALPINE AVE

Good

Over: FOX RIVER

069151803, Davis, IA

Built 2020 Load: 29.8 t ADT: 30

80TH ST

Good

Over: OTTER CREEK

000000000, Fayette, IA

Built 2011 Load: 29.8 t ADT: 49

N AVE

Good

Over: CREEK

000000000, Fayette, IA

Built 2010 Load: 29.8 t ADT: 29

LOCAL

Good

Over: BEAVER CREEK

090193504, Franklin, IA

Built 1985 Load: 29.8 t ADT: 128

FM RAVEN AVE

Good

Over: SPRING CREEK

092202502, Franklin, IA

Built 1983 Load: 29.8 t ADT: 59

LOCAL

Good

Over: BEAR CREEK

086190304, Hardin, IA

Built 2004 Load: 29.8 t ADT: 30

LOCAL

Good

Over: CREEK

089221702, Hardin, IA

Built 2005 Load: 29.8 t ADT: 34

LOCAL 135TH ST

Good

Over: LITTLE WAPSIPINICON RVR

098141003, Howard, IA

Built 1987 Load: 29.8 t ADT: 21

LOCAL

Good

Over: HALFWAY CREEK

089392304, Ida, IA

Built 1986 Load: 29.8 t ADT: 72

140TH AVE

Good

Over: SMALL CREEK

085030204, Jones, IA

Built 1987 Load: 29.8 t ADT: 25

305TH ST

Good

Over: RICHLAND CREEK

074101305, Keokuk, IA

Built 2020 Load: 29.8 t ADT: 20

SB US 61

Good

Over: LOST CREEK

2.4 mi. S of Jct. IA 16, Lee, IA

Built 1992 Load: 29.8 t ADT: 4,550

FM

Good

Over: WILLOW CREEK

095420602, O'Brien, IA

Built 1987 Load: 29.8 t ADT: 609

FM C-70

Good

Over: BIG WHISKEY CREEK

090453101, Plymouth, IA

Built 1985 Load: 29.8 t ADT: 559

FM C-60

Good

Over: PERRY CREEK

090471101, Plymouth, IA

Built 1984 Load: 29.8 t ADT: 908

FM

Good

Over: INDIAN CREEK

093470801, Plymouth, IA

Built 1984 Load: 29.8 t ADT: 319

FM

Good

Over: LITTLE CEDAR CK DD #181

091342004, Pocahontas, IA

Built 1986 Load: 29.8 t ADT: 34

FM-MISSOURI AVE

Good

Over: PIGEON CREEK

076442401, Pottawattamie, IA

Built 1986 Load: 29.8 t ADT: 60

460TH STREET

Good

Over: BALLARD CREEK

077391402, Pottawattamie, IA

Built 1988 Load: 29.8 t ADT: 26

185TH STREET

Good

Over: HONEY CREEK

077430706, Pottawattamie, IA

Built 1980 Load: 29.8 t ADT: 50

MALL DRIVE

Good

Over: MOSQUITO CREEK

Mall Dr over Mosquito Ck, Pottawattamie, IA

Built 1997 Load: 29.8 t ADT: 2,361

LOCAL

Good

Over: DEEP RIVER

079133103, Poweshiek, IA

Built 2010 Load: 29.8 t ADT: 20

FM

Good

Over: SMALL STREAM

094442102, Sioux, IA

Built 1985 Load: 29.8 t ADT: 2,539

62

Good

Over: WILLOW CREEK

094443601, Sioux, IA

Built 1984 Load: 29.8 t ADT: 31

LOCAL

Good

Over: SIX MILE CREEK

095472802, Sioux, IA

Built 1984 Load: 29.8 t ADT: 20

K64

Good

Over: SMALL STREAM

096440804, Sioux, IA

Built 1984 Load: 29.8 t ADT: 1,277

FM

Good

Over: DRY CREEK

096472502, Sioux, IA

Built 1982 Load: 29.8 t ADT: 60

LOCAL

Good

Over: NO NAME CREEK

096473405, Sioux, IA

Built 1982 Load: 29.8 t ADT: 60

TROUT RUN RD

Good

Over: CREEK

N edge of int. Stone Hill, Winneshiek, IA

Built 2013 Load: 29.8 t ADT: 2,553

LOCAL

Good

Over: MCELHANEY CREEK

089442802, Woodbury, IA

Built 1987 Load: 29.8 t ADT: 199

IA 3

Good

Over: DRAINAGE DITCH

0.1 Mi. E of Jct. US 218, Bremer, IA

Built 1967 Load: 29.9 t ADT: 5,400

FM

Good

Over: SMALL STREAM

090151702, Butler, IA

Built 2001 Load: 29.9 t ADT: 49

LOCAL

Good

Over: SMALL STREAM

090153503, Butler, IA

Built 2000 Load: 29.9 t ADT: 69

LOCAL

Good

Over: SMALL STREAM

090172304, Butler, IA

Built 2006 Load: 29.9 t ADT: 21

LOCAL

Good

Over: SMALL STREAM

090180201, Butler, IA

Built 2006 Load: 29.9 t ADT: 35

LOCAL

Good

Over: BEAVER CREEK

090181602, Butler, IA

Built 2008 Load: 29.9 t ADT: 30

255TH ST

Good

Over: SMALL STREAM

App. 550 W. of Silver Ln, Butler, IA

Built 2019 Load: 29.9 t ADT: 11

Showing 10,001-10,050 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.