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

450TH

Good

Over: SHELLROCK RIVER

099200901, Worth, IA

Built 1964 Load: 23.3 t ADT: 79

LOCAL

Good

Over: FIELD STREAM

083360901, Carroll, IA

Built 1996 Load: 23.4 t ADT: 45

FM

Good

Over: BR CEDAR RIVER

079032402, Cedar, IA

Built 2008 Load: 23.4 t ADT: 130

317TH ST

Good

Over: HONEY CREEK BRANCH

067332003, Taylor, IA

Built 2020 Load: 23.4 t ADT: 20

NAPLES AVE

Good

Over: CREEK

070332002, Taylor, IA

Built 2021 Load: 23.4 t ADT: 34

C38 TAHOE AV

Good

Over: STREAM

092113202, Bremer, IA

Built 2020 Load: 23.5 t ADT: 5

LOCAL

Good

Over: FIELD STREAM

084351504, Carroll, IA

Built 2008 Load: 23.5 t ADT: 150

450TH ST

Good

Over: MUD CREEK

094 41 06 01, O'Brien, IA

Built 2011 Load: 23.5 t ADT: 26

IA 3

Good

Over: WESTFIELD CREEK

2.0 mi E of E Jct IA 12, Plymouth, IA

Built 1975 Load: 23.5 t ADT: 940

I-280

Good

Over: DME RR

9.1 MI. S OF JCT. I-80, Scott, IA

Built 1971 Load: 23.5 t ADT: 24,200

LOCAL

Good

Over: STREAM

089420404, Woodbury, IA

Built 2002 Load: 23.5 t ADT: 20

LOCAL

Good

Over: FIELD STREAM

085362202, Carroll, IA

Built 1990 Load: 23.6 t ADT: 11

DANCER AVE

Good

Over: DEER CREEK

099181504, Mitchell, IA

Built 1979 Load: 23.6 t ADT: 44

LOCAL RD

Good

Over: BR YELLOW RIVER

097063506, Allamakee, IA

Built 2002 Load: 23.7 t ADT: 20

FM

Good

Over: BRANCH VILLAGE CREEK

098041307, Allamakee, IA

Built 2003 Load: 23.7 t ADT: 88

LOCAL

Good

Over: BR LEWIS JONES CREEK

098041802, Allamakee, IA

Built 2003 Load: 23.7 t ADT: 20

LOCAL RD

Good

Over: VILLAGE CREEK

098052003, Allamakee, IA

Built 2003 Load: 23.7 t ADT: 295

LOCAL

Good

Over: VILLAGE CREEK

098052802, Allamakee, IA

Built 2003 Load: 23.7 t ADT: 97

LOCAL

Good

Over: PAINT CREEK

097050405, Allamakee, IA

Built 2001 Load: 23.7 t ADT: 26

FM

Good

Over: FIELD STREAM

085340701, Carroll, IA

Built 2000 Load: 23.7 t ADT: 89

PHEASANT RD

Good

Over: BASS CREEK

095090403, Fayette, IA

Built 2008 Load: 23.7 t ADT: 88

1430 IOWA AVE

Good

Over: D.D.#159

094250902, Hancock, IA

Built 1984 Load: 23.7 t ADT: 30

155TH ST.

Good

Over: MINERAL CREEK

085022103, Jones, IA

Built 1992 Load: 23.7 t ADT: 11

450TH ST

Good

Over: BR OF CHARITON RIVER

071221103, Lucas, IA

Built 2018 Load: 23.7 t ADT: 16

660TH ST

Good

Over: SILVER CREEK

078400103, Shelby, IA

Built 2017 Load: 23.7 t ADT: 30

LOCAL

Good

Over: W BR LITTLE SIOUX RIVER

089442905, Woodbury, IA

Built 1987 Load: 23.7 t ADT: 110

I AVE

Good

Over: MIDDLE SOLDIER RIVER

084411701, Crawford, IA

Built 2022 Load: 23.8 t ADT: 26

LOCAL

Good

Over: NICHOLS CR

100112704, Howard, IA

Built 1957 Load: 23.8 t ADT: 41

US 34

Good

Over: DRAINAGE DITCH

1.5 mi. E of Jct. SR V37, Wapello, IA

Built 2005 Load: 23.8 t ADT: 9,600

LOCAL

Good

Over: SMALL STREAM

067162103, Appanoose, IA

Built 2009 Load: 23.9 t ADT: 16

LOCAL

Good

Over: WOLF BRANCH CREEK

069191102, Appanoose, IA

Built 2002 Load: 23.9 t ADT: 26

LOCAL

Good

Over: BEAVER CREEK

081272504, Dallas, IA

Built 1983 Load: 23.9 t ADT: 41

US 20 EB OFF RAMP

Good

Over: SOUTH BEAVER CREEK

0.1 MILE W OF JCT SR T19, Grundy, IA

Built 2003 Load: 23.9 t ADT: 350

NE CORY GROVE RD

Good

Over: OLD CHANNEL

081232506, Polk, IA

Built 2000 Load: 23.9 t ADT: 11

IA 906 WB

Good

Over: BNSF RR

1.0 MI. W. OF JCT. I-80, Pottawattamie, IA

Built 1968 Load: 23.9 t ADT: 3,900

LOCAL

Good

Over: WALNUT CREEK

074382101, Pottawattamie, IA

Built 1961 Load: 23.9 t ADT: 45

EAST 156TH ST N

Good

Over: SMALL STREAM

080161902, Poweshiek, IA

Built 1999 Load: 23.9 t ADT: 131

LOCAL

Good

Over: CALEB RIVER

067230604, Wayne, IA

Built 1998 Load: 23.9 t ADT: 45

430TH

Good

Over: SHELLROCK RIVER

099202201, Worth, IA

Built 1960 Load: 23.9 t ADT: 49

390TH ST

Good

Over: LINDSEY CREEK

091053203, Clayton, IA

Built 2006 Load: 24.0 t ADT: 26

231ST AVE

Good

Over: SMALL STREAM

087 04 19 09, Delaware, IA

Built 2013 Load: 24.0 t ADT: 11

V AVENUE

Good

Over: UNAMED CREEK

092100302, Fayette, IA

Built 2006 Load: 24.0 t ADT: 15

IA 149

Good

Over: ENGLISH CREEK

0.9 mi. S of Jct. SR F67, Iowa, IA

Built 1987 Load: 24.0 t ADT: 1,970

LOCAL

Good

Over: DR TO CEDAR CREEK

071200208, Lucas, IA

Built 2000 Load: 24.0 t ADT: 26

60TH AVE

Good

Over: WILDCAT CREEK

074213602, Marion, IA

Built 2015 Load: 24.0 t ADT: 21

300TH ST

Good

Over: LITTLE SILVER CREEK

078402701, Shelby, IA

Built 2017 Load: 24.0 t ADT: 72

LOCAL

Good

Over: MOSQUITO CREEK

080291701, Dallas, IA

Built 1979 Load: 24.1 t ADT: 35

13TH ST

Good

Over: IOWAY CREEK (13TH)

City of Ames, Story, IA

Built 1974 Load: 24.1 t ADT: 9,563

LOCAL

Good

Over: WOLF CREEK

070220805, Wayne, IA

Built 1995 Load: 24.1 t ADT: 20

LOCAL

Good

Over: SMALL

077323301, Adair, IA

Built 2005 Load: 24.2 t ADT: 5

Showing 9,451-9,500 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.