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: BUFFALO CREEK

098263601, Winnebago, IA

Built 2010 Load: 32.7 t ADT: 439

LOCAL

Good

Over: BLUE EARTH RIVER

099260702, Winnebago, IA

Built 2010 Load: 32.7 t ADT: 46

10TH AVE

Good

Over: BLUE EARTH RIVER

099260802, Winnebago, IA

Built 2011 Load: 32.7 t ADT: 120

MONEEK RD

Good

Over: YELLOW RIVER N FORK

S of Maple Valley Rd, Winneshiek, IA

Built 2014 Load: 32.7 t ADT: 11

ROGERS CREEK RD

Good

Over: ROGERS CREEK

300 W of Co. Rd. W14, Winneshiek, IA

Built 2012 Load: 32.7 t ADT: 120

W 14

Good

Over: TURKEY RIVER BRANCH

097091806, Winneshiek, IA

Built 2000 Load: 32.7 t ADT: 658

TOWN LINE RD

Good

Over: CREEK

097090601, Winneshiek, IA

Built 1979 Load: 32.7 t ADT: 59

235TH AVE

Good

Over: TEN MILE CREEK

235th Ave Madison Twp, Winneshiek, IA

Built 2013 Load: 32.7 t ADT: 49

LOCAL

Good

Over: TEN MILE CREEK

098090504, Winneshiek, IA

Built 1972 Load: 32.7 t ADT: 45

223RD AVE

Good

Over: CANOE CREEK

099080606, Winneshiek, IA

Built 1972 Load: 32.7 t ADT: 49

BEAR CREEK RD

Good

Over: BEAR CREEK

0.8 MI S of Int 360th St, Winneshiek, IA

Built 2017 Load: 32.7 t ADT: 29

LOCAL ROAD

Good

Over: CANOE CREEK

100083104, Winneshiek, IA

Built 1972 Load: 32.7 t ADT: 49

LOCAL

Good

Over: CREEK

100092103, Winneshiek, IA

Built 1979 Load: 32.7 t ADT: 5

LOCAL ROAD

Good

Over: SMALL DRY RUN

100102303, Winneshiek, IA

Built 1976 Load: 32.7 t ADT: 20

IA 31

Good

Over: STREAM

1.3 mi. S of SR D38, Woodbury, IA

Built 1966 Load: 32.7 t ADT: 1,030

IA 141

Good

Over: DRAINAGE DITCH

1.2 mi. E of Jct. SR K64, Woodbury, IA

Built 1959 Load: 32.7 t ADT: 1,490

D 25

Good

Over: SMALL STREAM

087461404, Woodbury, IA

Built 1975 Load: 32.7 t ADT: 578

LOCAL

Good

Over: MILLER CREEK

086430805, Woodbury, IA

Built 1991 Load: 32.7 t ADT: 45

LOCAL

Good

Over: LITTLE SIOUX RIVER

0864318, Woodbury, IA

Built 1994 Load: 32.7 t ADT: 45

LOCAL

Good

Over: STREAM

0874208, Woodbury, IA

Built 1994 Load: 32.7 t ADT: 34

LOCAL

Good

Over: STREAM

0874214, Woodbury, IA

Built 2004 Load: 32.7 t ADT: 20

FM

Good

Over: LITTLE SIOUX RIVER

087431903, Woodbury, IA

Built 1992 Load: 32.7 t ADT: 110

LOCAL

Good

Over: WOLF CREEK

0874407, Woodbury, IA

Built 1991 Load: 32.7 t ADT: 26

LOCAL

Good

Over: EAST BRANCH WOLF CREEK

087441802, Woodbury, IA

Built 1987 Load: 32.7 t ADT: 30

FM

Good

Over: STREAM

088420203, Woodbury, IA

Built 2008 Load: 32.7 t ADT: 330

160TH ST

Good

Over: THREE MILE CREEK

0884303, Woodbury, IA

Built 2002 Load: 32.7 t ADT: 199

200TH ST

Good

Over: WHISKEY CREEK

088452603, Woodbury, IA

Built 2001 Load: 32.7 t ADT: 15

FM

Good

Over: DRAINAGE

088462903, Woodbury, IA

Built 1999 Load: 32.7 t ADT: 1,236

LOCAL

Good

Over: STREAM

0894201, Woodbury, IA

Built 1990 Load: 32.7 t ADT: 34

LOCAL

Good

Over: SMALL

0894310, Woodbury, IA

Built 2009 Load: 32.7 t ADT: 15

FAYETTE AVE

Good

Over: STREAM

089451002, Woodbury, IA

Built 1994 Load: 32.7 t ADT: 5

LOCAL

Good

Over: STREAM

089452506, Woodbury, IA

Built 1997 Load: 32.7 t ADT: 34

OLD HWY 20

Good

Over: SMALL STREAM

089453501, Woodbury, IA

Built 2007 Load: 32.7 t ADT: 159

FM

Good

Over: CREEK

089440605, Woodbury, IA

Built 2006 Load: 32.7 t ADT: 11

FM

Good

Over: CREEK

089440608, Woodbury, IA

Built 2006 Load: 32.7 t ADT: 30

K64(MOVILLE RD)

Good

Over: STREAM

0884534, Woodbury, IA

Built 2012 Load: 32.7 t ADT: 957

6TH ST

Good

Over: PERRY CREEK CONDUIT

000000000, Woodbury, IA

Built 2000 Load: 32.7 t ADT: 5,704

W CLIFTON ST

Good

Over: BACON CREEK

000000000, Woodbury, IA

Built 2005 Load: 32.7 t ADT: 4,243

TAFT ST

Good

Over: STREAM

0.1 mi. E of jct US 75, Woodbury, IA

Built 2000 Load: 32.7 t ADT: 1,721

WHEELERWOOD

Good

Over: DRAINAGE DITCH

098210802, Worth, IA

Built 1999 Load: 32.7 t ADT: 265

FIR AVE

Good

Over: DRAINAGE DITCH

.6 m S of IA 9, Worth, IA

Built 2012 Load: 32.7 t ADT: 207

CARDINAL

Good

Over: BEAVER CREEK

098222804, Worth, IA

Built 2005 Load: 32.7 t ADT: 15

APPLE

Good

Over: BEAVER CREEK

000000000, Worth, IA

Built 2009 Load: 32.7 t ADT: 41

WHEELERWOOD

Good

Over: STREAM

099211704, Worth, IA

Built 1998 Load: 32.7 t ADT: 285

FINCH

Good

Over: ELK CREEK

099221206, Worth, IA

Built 2006 Load: 32.7 t ADT: 29

480TH

Good

Over: STREAM

100192801, Worth, IA

Built 2006 Load: 32.7 t ADT: 5

460TH

Good

Over: DEER CREEK

100193503, Worth, IA

Built 2003 Load: 32.7 t ADT: 41

FM

Good

Over: DRAINAGE DITCH

090231206, Wright, IA

Built 2002 Load: 32.7 t ADT: 390

FM

Good

Over: BUCK CREEK

090243101, Wright, IA

Built 2003 Load: 32.7 t ADT: 778

DAVIS AVE

Good

Over: STREAM

090261601, Wright, IA

Built 2013 Load: 32.7 t ADT: 26

Showing 12,251-12,300 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.