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

B 14

Fair

Over: SMALL STREAM

097451801, Sioux, IA

Built 1990 Load: 99.9 t ADT: 26

LOCAL

Fair

Over: SM STREAM

097460702, Sioux, IA

Built 1994 Load: 99.9 t ADT: 11

FM

Fair

Over: SMALL STREAM

094433601, Sioux, IA

Built 1986 Load: 99.9 t ADT: 61

FM

Fair

Over: ORANGE CITY SLOUGH

095442101, Sioux, IA

Built 1992 Load: 99.9 t ADT: 60

LOCAL

Fair

Over: STREAM

094432202, Sioux, IA

Built 1993 Load: 99.9 t ADT: 15

LOCAL

Fair

Over: SMALL STREAM

095433402, Sioux, IA

Built 1994 Load: 99.9 t ADT: 11

LILY AVE

Fair

Over: STREAM

094431002, Sioux, IA

Built 2000 Load: 99.9 t ADT: 41

LOCAL

Fair

Over: SMALL

094432401, Sioux, IA

Built 1985 Load: 99.9 t ADT: 15

LOCAL

Fair

Over: SMALL

094473401, Sioux, IA

Built 1988 Load: 99.9 t ADT: 90

LOCAL

Fair

Over: SMALL

096462601, Sioux, IA

Built 1981 Load: 99.9 t ADT: 80

LOCAL

Fair

Over: SMALL

095453401, Sioux, IA

Built 1987 Load: 99.9 t ADT: 131

LOCAL

Fair

Over: SMALL

097433302, Sioux, IA

Built 1983 Load: 99.9 t ADT: 71

LOCAL

Fair

Over: SMALL

097461002, Sioux, IA

Built 1984 Load: 99.9 t ADT: 60

280TH ST

Fair

Over: SMALL

097440801, Sioux, IA

Built 1978 Load: 99.9 t ADT: 45

R70/580TH AVE

Fair

Over: SMALL STREAM

083233302, Story, IA

Built 1987 Load: 99.9 t ADT: 818

US 65

Fair

Over: STREAM

0.3 mi. N of Jct. SR J54, Wayne, IA

Built 1941 Load: 99.9 t ADT: 1,240

FM

Fair

Over: MEDICINE CREEK

067222101, Wayne, IA

Built 1996 Load: 99.9 t ADT: 60

FM

Fair

Over: SMALL CREEK

087420902, Woodbury, IA

Built 1962 Load: 99.9 t ADT: 339

WESTERN AVENUE

Good

Over: WAUBONSIE DITCH

070430910, Fremont, IA

Built 1996 ADT: 180

LOCAL

Good

Over: SOUTH AVERY CREEK

072151503, Wapello, IA

Built 1930 ADT: 11

298TH AVE

Good

Over: PLUM CREEK

088033204, Delaware, IA

Built 2005 Load: 4.5 t ADT: 78

I AVE

Good

Over: DEVILS RUN

079112802, Iowa, IA

Built 2015 Load: 5.1 t ADT: 20

1370 UNION AVE

Good

Over: EAST IOWA RIVER

094231604, Hancock, IA

Built 1983 Load: 9.2 t ADT: 21

1240 UNION AVE

Good

Over: EAST IOWA RIVER

094232104, Hancock, IA

Built 1979 Load: 9.2 t ADT: 26

1390 120TH ST

Good

Over: WEST BRANCH IOWA RIVER

094242903, Hancock, IA

Built 1984 Load: 9.2 t ADT: 41

FM

Good

Over: BLACK HAWK CREEK

87-14-06-02-10, Black Hawk, IA

Built 1973 Load: 9.7 t ADT: 98

225TH ST

Good

Over: ELK CREEK

068270203, Decatur, IA

Built 2008 Load: 9.8 t ADT: 21

CEDAR BRIDGE RD

Good

Over: CEDAR CREEK

076272006, Madison, IA

Built 2004 Load: 11.0 t ADT: 11

ROOSEVELT AVE

Good

Over: CREEK

090432802, Plymouth, IA

Built 1956 Load: 11.1 t ADT: 20

KEY AVE

Good

Over: BIG WHISKEY CREEK

090453102, Plymouth, IA

Built 1952 Load: 11.7 t ADT: 26

STEIL LANE

Good

Over: CREEK

089E11006, Dubuque, IA

Built 2016 Load: 12.0 t ADT: 5

LAREDO RD

Good

Over: TURKEY RIVER

040000520, Clayton, IA

Built 2002 Load: 12.6 t ADT: 799

LOCAL

Good

Over: FIELD STREAM

085333002, Carroll, IA

Built 1997 Load: 13.0 t ADT: 11

FM

Good

Over: BRUSH CREEK

069251302, Decatur, IA

Built 2006 Load: 13.4 t ADT: 34

LOCAL

Good

Over: DD #25

087352101, Sac, IA

Built 2001 Load: 13.5 t ADT: 30

IA 10

Good

Over: DRAINAGE DITCH

1.3 mi. E of S.R. B-46, Sioux, IA

Built 1954 Load: 13.6 t ADT: 1,910

1000TH ST

Good

Over: BUCK CREEK

079372203, Shelby, IA

Built 2018 Load: 13.9 t ADT: 51

275TH ST

Good

Over: STREAM

0682532303, Decatur, IA

Built 2011 Load: 14.0 t ADT: 40

KINGBIRD AVE

Good

Over: WATERWAY

077350303, Cass, IA

Built 2000 Load: 14.3 t ADT: 30

R30 W AVE

Good

Over: TRIB OF BEAVER CREEK

080261102, Dallas, IA

Built 1974 Load: 14.3 t ADT: 1,934

290TH ST

Good

Over: DICKENSON BRANCH

067260305, Decatur, IA

Built 2011 Load: 14.3 t ADT: 5

LOCAL

Good

Over: BEAVER CREEK

079313303, Guthrie, IA

Built 2004 Load: 14.3 t ADT: 71

140TH ST

Good

Over: LITTLE RIVER

070253001, Decatur, IA

Built 2005 Load: 14.4 t ADT: 41

LOCAL

Good

Over: STREAM

069270314, Decatur, IA

Built 2005 Load: 14.5 t ADT: 11

IA 9

Good

Over: OCHEYEDON RIVER

1.6 mi. E of Jct. U.S. 59, Osceola, IA

Built 1987 Load: 14.7 t ADT: 2,020

LOCAL

Good

Over: FIELD STREAM

083 33 11 02, Carroll, IA

Built 2010 Load: 15.0 t ADT: 15

LOCAL

Good

Over: CREEK

076351604, Cass, IA

Built 2004 Load: 15.4 t ADT: 5

ELDORA RD

Good

Over: TRIB TO BLACK HAWK CREEK

88-14-33-07-10, Black Hawk, IA

Built 1927 Load: 15.9 t ADT: 79

ORANGE RD

Good

Over: DUTCH BRANCH

078381805, Shelby, IA

Built 2019 Load: 15.9 t ADT: 26

LOCAL

Good

Over: LITTLE RIVER

068251803, Decatur, IA

Built 1999 Load: 16.0 t ADT: 35

Showing 9,001-9,050 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.