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

LOC 290TH AVE

Good

Over: CALAMUS CREEK

097293201, Kossuth, IA

Built 1995 Load: 45.1 t ADT: 30

LOC 380TH ST

Good

Over: PRAIRIE CREEK

098301301, Kossuth, IA

Built 1992 Load: 45.1 t ADT: 35

LOC 200TH AVE

Good

Over: DD #90

099271908, Kossuth, IA

Built 1992 Load: 45.1 t ADT: 62

LOC 425TH ST

Good

Over: UNION SLOUGH DITCH

099282403, Kossuth, IA

Built 1994 Load: 45.1 t ADT: 50

FM

Good

Over: EAST NODAWAY RIVER

070352001, Taylor, IA

Built 2009 Load: 45.1 t ADT: 309

LOCAL

Good

Over: CANOE CREEK

099081508, Winneshiek, IA

Built 1989 Load: 45.1 t ADT: 70

MILLER CREEK RD

Good

Over: TRIB TO MILLER CREEK

87-12-03-05-10, Black Hawk, IA

Built 1988 Load: 45.2 t ADT: 29

HOLMES RD

Good

Over: ROCK CREEK

87-14-25-02-10, Black Hawk, IA

Built 1993 Load: 45.2 t ADT: 20

F21 270TH ST

Good

Over: BARBER CREEK

081E33203, Clinton, IA

Built 2022 Load: 45.2 t ADT: 100

MONTANA AVE

Good

Over: CREEK

093291304, Humboldt, IA

Built 2014 Load: 45.2 t ADT: 40

400TH ST

Good

Over: W NUSHNABOTNA

074400304, Pottawattamie, IA

Built 2006 Load: 45.2 t ADT: 40

295TH ST

Good

Over: EAST BR INDIAN CREEK

082220903, Story, IA

Built 2014 Load: 45.2 t ADT: 131

250TH ST

Good

Over: EAST INDIAN CREEK

W of INT w/ 670th Ave, Story, IA

Built 2015 Load: 45.2 t ADT: 80

LOCAL

Good

Over: CREEK

096080503, Winneshiek, IA

Built 2005 Load: 45.2 t ADT: 70

FM

Good

Over: TROUT CREEK BRANCH

098083305, Winneshiek, IA

Built 1995 Load: 45.2 t ADT: 137

111TH AVE

Good

Over: N FORK OF YELLOW RIVR

096070204, Winneshiek, IA

Built 2000 Load: 45.2 t ADT: 39

LOCAL

Good

Over: STREAM

067181604, Appanoose, IA

Built 1999 Load: 45.3 t ADT: 62

140TH ST

Good

Over: FLOOD CREEK

093162603, Butler, IA

Built 2009 Load: 45.3 t ADT: 49

US 18 EB IA 27 SB

Good

Over: UPRR

1.5 mi. W of US 65, Cerro Gordo, IA

Built 1997 Load: 45.3 t ADT: 4,450

LOCAL-E AVE.

Good

Over: WEST FORK LITTLE SIOUX

092423502, Cherokee, IA

Built 1998 Load: 45.3 t ADT: 90

FM

Good

Over: LITTLE WAPSIPINICON

097142501, Chickasaw, IA

Built 2009 Load: 45.3 t ADT: 187

US 18

Good

Over: LITTLE WAP RIVER OVRFLW

3.0 mi. W of W Jct. US 63, Chickasaw, IA

Built 2001 Load: 45.3 t ADT: 3,030

LOCAL

Good

Over: BEE CREEK

071262205, Clarke, IA

Built 2007 Load: 45.3 t ADT: 26

LOCAL

Good

Over: OTTER CREEK

072241001, Clarke, IA

Built 2007 Load: 45.3 t ADT: 26

LOCAL 205TH AVE

Good

Over: BUCK CREEK

087051108, Delaware, IA

Built 1995 Load: 45.3 t ADT: 26

B23 110TH ST

Good

Over: LITTLE CEDAR RIVER

097162405, Floyd, IA

Built 2009 Load: 45.3 t ADT: 78

T AVE

Good

Over: STREAM

084290502, Greene, IA

Built 2002 Load: 45.3 t ADT: 11

T AVE

Good

Over: BUTTRICK CREEK

084292002, Greene, IA

Built 2001 Load: 45.3 t ADT: 15

160 TH

Good

Over: BUTTRICKS CREEK

084300201, Greene, IA

Built 2003 Load: 45.3 t ADT: 21

210 TH

Good

Over: HARDIN CREEK

084303201, Greene, IA

Built 2002 Load: 45.3 t ADT: 72

LOC 1220 270 ST

Good

Over: DD 1 & 2

096251201, Hancock, IA

Built 2007 Load: 45.3 t ADT: 30

LOCAL

Good

Over: DRAINAGE DITCH

091271402, Humboldt, IA

Built 2004 Load: 45.3 t ADT: 34

LOCAL

Good

Over: CREEK

093283104, Humboldt, IA

Built 2005 Load: 45.3 t ADT: 15

LOCAL

Good

Over: BR MIDDLE FORK ENGLISH

078112612, Iowa, IA

Built 2004 Load: 45.3 t ADT: 140

LOCAL

Good

Over: MUD CREEK

081211301, Jasper, IA

Built 1988 Load: 45.3 t ADT: 26

LOC 230TH ST

Good

Over: LOTTS CREEK

096303401, Kossuth, IA

Built 1999 Load: 45.3 t ADT: 15

LOC 450TH ST

Good

Over: MIDDLE BRANCH BLUE EARTH

099270701, Kossuth, IA

Built 2001 Load: 45.3 t ADT: 81

LOCAL

Good

Over: CEDAR CREEK

076282504, Madison, IA

Built 1992 Load: 45.3 t ADT: 150

LOCAL

Good

Over: BRUSH CREEK

082172101, Marshall, IA

Built 2006 Load: 45.3 t ADT: 51

LOCAL

Good

Over: NORTH TIMBER CREEK

083192304, Marshall, IA

Built 1998 Load: 45.3 t ADT: 21

N. 18TH AVE.

Good

Over: LINN CREEK

084173000, Marshall, IA

Built 1990 Load: 45.3 t ADT: 1,783

QUANDT RD

Good

Over: WAUBONSIE CREEK

071432503, Mills, IA

Built 2014 Load: 45.3 t ADT: 34

FM

Good

Over: LITTLE BEAR CREEK

080142801, Poweshiek, IA

Built 2007 Load: 45.3 t ADT: 30

LOCAL

Good

Over: STREAM

068281804, Ringgold, IA

Built 1998 Load: 45.3 t ADT: 20

B 58 (470TH ST)

Good

Over: SIX MILE CREEK

094481301, Sioux, IA

Built 2012 Load: 45.3 t ADT: 40

LINCOLN HWY

Good

Over: W BR INDIAN CREEK

000000000, Story, IA

Built 2000 Load: 45.3 t ADT: 6,217

LOCAL

Good

Over: SUGAR CREEK

084162001, Tama, IA

Built 2006 Load: 45.3 t ADT: 20

FM

Good

Over: LITTLE WOLF CREEK

086163201, Tama, IA

Built 1995 Load: 45.3 t ADT: 69

LOCAL

Good

Over: LITTLE CEDAR CREEK

069080204, Van Buren, IA

Built 1999 Load: 45.3 t ADT: 26

FM

Good

Over: BRANCH MIDDLE AVERY CRK

072150702, Wapello, IA

Built 2008 Load: 45.3 t ADT: 1,250

Showing 15,101-15,150 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.