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

LOCAL

Good

Over: DD

091272402, Humboldt, IA

Built 2007 Load: 48.0 t ADT: 45

LOCAL

Good

Over: DD

091282701, Humboldt, IA

Built 2008 Load: 48.0 t ADT: 34

LOCAL

Good

Over: ELK CREEK

087390302, Ida, IA

Built 1998 Load: 48.0 t ADT: 30

LOCAL RD

Good

Over: BATTLE CREEK

087410201, Ida, IA

Built 1998 Load: 48.0 t ADT: 30

LOCAL

Good

Over: BR OF MAPLE RIVER

089390202, Ida, IA

Built 1996 Load: 48.0 t ADT: 21

WW AVE

Good

Over: DEER CREEK

078091102, Iowa, IA

Built 2021 Load: 48.0 t ADT: 50

107TH ST

Good

Over: SMALL STREAM

081110207, Iowa, IA

Built 2019 Load: 48.0 t ADT: 45

F15 (108TH ST)

Good

Over: SMALL STREAM

081110 08, Iowa, IA

Built 2013 Load: 48.0 t ADT: 60

400TH ST

Good

Over: LUX CREEK

087E30203, Jackson, IA

Built 2021 Load: 48.0 t ADT: 78

25TH STREET

Good

Over: PIONEER CREEK

083033303, Jones, IA

Built 2004 Load: 48.0 t ADT: 59

230TH AVE.

Good

Over: S FORK WALNUT CREEK

083041606, Jones, IA

Built 1990 Load: 48.0 t ADT: 47

35TH ST.

Good

Over: WHITE OAK CREEK

083042403, Jones, IA

Built 1990 Load: 48.0 t ADT: 34

JONES-DELAWARE

Good

Over: GROVE CREEK

086040303, Jones, IA

Built 1992 Load: 48.0 t ADT: 20

FM

Good

Over: ENGLISH RIVER

077130502, Keokuk, IA

Built 2006 Load: 48.0 t ADT: 35

LOCAL

Good

Over: SUGAR CREEK

068070202, Lee, IA

Built 1994 Load: 48.0 t ADT: 20

LOCAL CO ROAD

Good

Over: LITTLE SUGAR CREEK

068073602, Lee, IA

Built 1999 Load: 48.0 t ADT: 100

LOCAL

Good

Over: LOST CREEK

069043204, Lee, IA

Built 1993 Load: 48.0 t ADT: 131

ROOSEVELT ST

Good

Over: EAST OTTER CREEK

085072803, Linn, IA

Built 1999 Load: 48.0 t ADT: 471

WB US 30

Good

Over: MORGAN CREEK

3.6 MI W OF JCT US 151, Linn, IA

Built 1992 Load: 48.0 t ADT: 7,700

IA 14

Good

Over: CHARITON RIVER

0.9 MI. S OF JCT. US 34, Lucas, IA

Built 1988 Load: 48.0 t ADT: 2,270

LOCAL ROAD

Good

Over: BLOOD RUN CREEK

100482301, Lyon, IA

Built 2000 Load: 48.0 t ADT: 21

FM

Good

Over: HONEY CREEK

074180302, Marion, IA

Built 2004 Load: 48.0 t ADT: 60

LOCAL

Good

Over: BURNETT CR

084170502, Marshall, IA

Built 2004 Load: 48.0 t ADT: 35

FM

Good

Over: CREEK

084180801, Marshall, IA

Built 2004 Load: 48.0 t ADT: 108

FM

Good

Over: CREEK

084190305, Marshall, IA

Built 2004 Load: 48.0 t ADT: 59

LOCAL

Good

Over: BR MINERVA CREEK

084191501, Marshall, IA

Built 1992 Load: 48.0 t ADT: 21

FM

Good

Over: CREEK

071180705, Monroe, IA

Built 2006 Load: 48.0 t ADT: 60

LOCAL RD

Good

Over: LOCAL CREEK

072191802, Monroe, IA

Built 2002 Load: 48.0 t ADT: 20

LOCAL

Good

Over: MILL CREEK

096412402, O'Brien, IA

Built 1988 Load: 48.0 t ADT: 15

LOCAL

Good

Over: LITTLE FLOYD RIVER

096420102, O'Brien, IA

Built 1992 Load: 48.0 t ADT: 41

MARBLE AVE

Good

Over: ELLIOT CREEK

90450210, Plymouth, IA

Built 2020 Load: 48.0 t ADT: 26

190TH ST

Good

Over: BIG WHISKEY SLOUGH

092432301, Plymouth, IA

Built 1990 Load: 48.0 t ADT: 26

FM-JUNIPER ROAD

Good

Over: HENSCHAL CREEK

076432503, Pottawattamie, IA

Built 1996 Load: 48.0 t ADT: 50

FM

Good

Over: HONEY CREEK

069323201, Taylor, IA

Built 1998 Load: 48.0 t ADT: 45

LOCAL

Good

Over: MIDDLE PLATTE RIVER

071312803, Union, IA

Built 1994 Load: 48.0 t ADT: 11

LOCAL

Good

Over: TRIB DES MOINES RIVER

070111709, Van Buren, IA

Built 2002 Load: 48.0 t ADT: 91

FM

Good

Over: DRAINAGE DITCH NO 4

088270801, Webster, IA

Built 2007 Load: 48.0 t ADT: 40

LOCAL

Good

Over: PIKE RUN

099252402, Winnebago, IA

Built 2005 Load: 48.0 t ADT: 26

LOCAL

Good

Over: CREEK

096101303, Winneshiek, IA

Built 1997 Load: 48.0 t ADT: 59

LOCAL ROAD

Good

Over: WONDER CREEK

097102306, Winneshiek, IA

Built 1998 Load: 48.0 t ADT: 26

FM

Good

Over: TROUT CREEK

098083305, Winneshiek, IA

Built 1995 Load: 48.0 t ADT: 137

LOCAL ROAD

Good

Over: DRY RUN CREEK

098093504, Winneshiek, IA

Built 2007 Load: 48.0 t ADT: 128

288TH AVE

Good

Over: COLDWATER CREEK

0.5 Mi S A18, Winneshiek, IA

Built 2015 Load: 48.0 t ADT: 29

K49 EMMETT AVE

Good

Over: ELLIOTT CREEK

89452102, Woodbury, IA

Built 2016 Load: 48.0 t ADT: 390

R33(HANCOCK AV)

Good

Over: OTTER CREEK

093253202, Wright, IA

Built 2013 Load: 48.0 t ADT: 499

SB US 218

Good

Over: OVER CC RR

0.5 MI. N OF JCT. IA 57, Black Hawk, IA

Built 1995 Load: 48.1 t ADT: 11,850

295TH

Good

Over: SHELL ROCK RIVER

097192703, Cerro Gordo, IA

Built 1985 Load: 48.1 t ADT: 62

LOCAL

Good

Over: BEAVER CREEK

096151202, Floyd, IA

Built 1990 Load: 48.1 t ADT: 39

FM

Good

Over: ROCK CREEK

086123402, Benton, IA

Built 2005 Load: 48.2 t ADT: 10

CUNNINGHAM RD

Good

Over: CAMP CREEK

89-11-13-06-10, Black Hawk, IA

Built 2006 Load: 48.2 t ADT: 44

Showing 15,551-15,600 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.