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

US 151 SB

Good

Over: PRARIE CREEK

1.9 MI N. of Jct. SR Y21, Dubuque, IA

Built 2003 Load: 38.8 t ADT: 2,750

215 AVE

Good

Over: PLUM CREEK

069430304, Fremont, IA

Built 1992 Load: 38.8 t ADT: 36

130 STREET

Good

Over: HUNTER'S BRANCH

070402201, Fremont, IA

Built 1986 Load: 38.8 t ADT: 35

B AVENUE

Good

Over: TRIB TO BEAVER CREEK

089182002, Grundy, IA

Built 2006 Load: 38.8 t ADT: 39

WB US 20

Good

Over: LOCAL STREAM

0.1 MILES W OF JCT SR T55, Grundy, IA

Built 2000 Load: 38.8 t ADT: 6,500

310TH ST

Good

Over: UNNAMED CREEK

078122101, Iowa, IA

Built 2013 Load: 38.8 t ADT: 71

FM

Good

Over: OLD MANS CREEK

080113404, Iowa, IA

Built 1992 Load: 38.8 t ADT: 40

LOCAL

Good

Over: NORTH SKUNK RIVER

080190104, Jasper, IA

Built 1997 Load: 38.8 t ADT: 26

LOCAL

Good

Over: STREAM

074112801, Keokuk, IA

Built 2003 Load: 38.8 t ADT: 26

FM

Good

Over: ENGLISH RIVER

077121802, Keokuk, IA

Built 2002 Load: 38.8 t ADT: 50

LOCAL SECONDARY

Good

Over: SUGAR CREEK

068052906, Lee, IA

Built 1992 Load: 38.8 t ADT: 181

LOCAL RD

Good

Over: MIDDLE RIVER

076293104, Madison, IA

Built 1998 Load: 38.8 t ADT: 40

FA-GASTON AVE

Good

Over: SILVER CREEK

072420103, Mills, IA

Built 1991 Load: 38.8 t ADT: 139

LCL-BROTHERS AV

Good

Over: KEG CREEK

073420801, Mills, IA

Built 1992 Load: 38.8 t ADT: 71

LOCAL ROAD

Good

Over: STREAM

082422605, Monona, IA

Built 1999 Load: 38.8 t ADT: 34

FM

Good

Over: AVERY CREEK

071160903, Monroe, IA

Built 1988 Load: 38.8 t ADT: 50

W 1ST STREET

Good

Over: ROCK CREEK

080242105, Polk, IA

Built 2007 Load: 38.8 t ADT: 4,709

440TH ST

Good

Over: FARM CREEK

074392802, Pottawattamie, IA

Built 1999 Load: 38.8 t ADT: 11

PINOAK ROAD

Good

Over: SILVER CREEK

076400901, Pottawattamie, IA

Built 2002 Load: 38.8 t ADT: 26

WHIPPERWILL RD

Good

Over: WALNUT CREEK

077381007, Pottawattamie, IA

Built 2006 Load: 38.8 t ADT: 79

FM

Good

Over: BIG BEAR CREEK

080131702, Poweshiek, IA

Built 1988 Load: 38.8 t ADT: 70

285TH ST

Good

Over: CREEK

080E42303, Scott, IA

Built 1997 Load: 38.8 t ADT: 50

FM

Good

Over: PLATTE BRANCH

067323003, Taylor, IA

Built 2005 Load: 38.8 t ADT: 20

LOCAL

Good

Over: GRAND RIVER

072281803, Union, IA

Built 1995 Load: 38.8 t ADT: 26

LOCAL

Good

Over: LIZARD CREEK

090303101, Webster, IA

Built 1998 Load: 38.8 t ADT: 21

FM

Good

Over: FARMERS DITCH

086460301, Woodbury, IA

Built 1994 Load: 38.8 t ADT: 60

WHEELERWOOD

Good

Over: WINNEBAGO RIVER

098213206, Worth, IA

Built 1992 Load: 38.8 t ADT: 108

LOCAL ROAD

Good

Over: IOWA RIVER

093231801, Wright, IA

Built 2001 Load: 38.8 t ADT: 73

SR V 40

Good

Over: PRAIRIE CREEK

083121002, Benton, IA

Built 2011 Load: 38.9 t ADT: 25

11TH AVE

Good

Over: TRIBUTARY TO STEIN CREEK

084122902, Benton, IA

Built 2020 Load: 38.9 t ADT: 15

KING RD

Good

Over: ROCK CREEK

87-11-33-02-10, Black Hawk, IA

Built 2020 Load: 38.9 t ADT: 70

HESS RD

Good

Over: MILLER CREEK

87-13-24-02-10, Black Hawk, IA

Built 2010 Load: 38.9 t ADT: 26

HICKS RD

Good

Over: TRIB TO BLACK HAWK CREEK

87-14-17-02-10, Black Hawk, IA

Built 2004 Load: 38.9 t ADT: 59

HAMMOND AVE

Good

Over: TRIB TO MILLER CREEK

88-13-35-02-10, Black Hawk, IA

Built 2017 Load: 38.9 t ADT: 97

W DUNKERTON RD

Good

Over: TRIB TO CEDAR RIVER

90-13-33-03-10, Black Hawk, IA

Built 2017 Load: 38.9 t ADT: 845

650TH ST

Good

Over: DRAINAGE DITCH DIST 1

090353601, Buena Vista, IA

Built 2013 Load: 38.9 t ADT: 45

500TH ST

Good

Over: RACCOON RIVER

092361701, Buena Vista, IA

Built 2011 Load: 38.9 t ADT: 15

280TH ST

Good

Over: FIELD STREAM

082350401, Carroll, IA

Built 2022 Load: 38.9 t ADT: 60

PHOENIX AVE

Good

Over: WILLEY BRANCH

083342702, Carroll, IA

Built 2012 Load: 38.9 t ADT: 29

PHOENIX AVE

Good

Over: STORM CREEK

084341002, Carroll, IA

Built 2023 Load: 38.9 t ADT: 20

F46 310TH ST

Good

Over: BR WAPSINONOC CREEK

079042301, Cedar, IA

Built 2020 Load: 38.9 t ADT: 80

TAYLOR AVE

Good

Over: SUGAR CREEK

080012902, Cedar, IA

Built 2023 Load: 38.9 t ADT: 26

250TH ST

Good

Over: SMALL

080022401, Cedar, IA

Built 2010 Load: 38.9 t ADT: 26

X 60(OCEAN AVE)

Good

Over: SUGAR CREEK

081021604, Cedar, IA

Built 2010 Load: 38.9 t ADT: 70

M 21 (V AVE)

Good

Over: PITCHER CREEK

090390302, Cherokee, IA

Built 2012 Load: 38.9 t ADT: 390

V48 QUINLAN AVE

Good

Over: EAST FORK WAPSIPINICON

094121310, Chickasaw, IA

Built 2022 Load: 38.9 t ADT: 540

N18 330TH AVE

Good

Over: POOL-MUD LAKE

097352502, Clay, IA

Built 2018 Load: 38.9 t ADT: 350

GALAXY RD

Good

Over: TURKEY RIVER

092040689, Clayton, IA

Built 2012 Load: 38.9 t ADT: 30

LILY AVE

Good

Over: TRIB N CHEQUEST LAKE CR

070141304, Davis, IA

Built 2017 Load: 38.9 t ADT: 60

245TH AVE

Good

Over: PENNS BRANCH

088040904, Delaware, IA

Built 2018 Load: 38.9 t ADT: 29

Showing 13,851-13,900 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.