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: SO BR LITTLE FLOYD RIVER

096411001, O'Brien, IA

Built 2002 Load: 22.7 t ADT: 5

IA 60

Good

Over: ENGELS CREEK

1.5 mi. N of US 18, O'Brien, IA

Built 2006 Load: 22.7 t ADT: 5,300

275TH ST

Good

Over: STREAM

080E22904, Scott, IA

Built 1976 Load: 22.7 t ADT: 15

LOCAL

Good

Over: STREAM

081381402, Shelby, IA

Built 1996 Load: 22.7 t ADT: 5

IA 12

Good

Over: DRAINAGE

1.3 mi. S of Jct. IA 10, Sioux, IA

Built 1954 Load: 22.7 t ADT: 1,120

I 35 NB

Good

Over: IOWA RIVER

4.0 mi. N of SR C-70, Wright, IA

Built 1974 Load: 22.7 t ADT: 8,250

315 ST

Good

Over: CREEK

078361605, Audubon, IA

Built 2000 Load: 22.8 t ADT: 30

LOCAL

Good

Over: BRUSHY CREEK

083353502, Carroll, IA

Built 1984 Load: 22.8 t ADT: 89

FM

Good

Over: STORM CREEK

084340901, Carroll, IA

Built 1983 Load: 22.8 t ADT: 60

133RD AVE

Good

Over: TROUT RIVER

098072806, Winneshiek, IA

Built 1967 Load: 22.8 t ADT: 49

100TH ST

Good

Over: ELK CREEK

97132001, Chickasaw, IA

Built 2014 Load: 22.9 t ADT: 30

T AVE

Good

Over: BOECK CREEK

082381001, Crawford, IA

Built 2005 Load: 22.9 t ADT: 15

170TH ST

Good

Over: EMIGRANT CREEK

084402002, Crawford, IA

Built 2000 Load: 22.9 t ADT: 26

337TH ST

Good

Over: SNAKE CREEK

082293503, Greene, IA

Built 1978 Load: 22.9 t ADT: 26

330TH TRL

Good

Over: NORTH CEDAR CREEK

732024, Lucas, IA

Built 2012 Load: 22.9 t ADT: 21

LOCAL

Good

Over: SMALL STREAM

094483502, Sioux, IA

Built 1977 Load: 22.9 t ADT: 34

WATROUS ST

Good

Over: SUGAR CREEK

070210603, Wayne, IA

Built 2018 Load: 22.9 t ADT: 50

FM

Good

Over: WOLF CREEK

087440501, Woodbury, IA

Built 2009 Load: 22.9 t ADT: 399

HERON AVE

Good

Over: CREEK

T81N R35W Sec20, Audubon, IA

Built 2017 Load: 23.0 t ADT: 41

I-35

Good

Over: DRAINAGE DITCH NO.48

0.3 MI S OF SR C47, Franklin, IA

Built 1974 Load: 23.0 t ADT: 15,100

MAIN STREET

Good

Over: ENGLISH CREEK

0.8 mi. S of Jct. SR F67, Iowa, IA

Built 1987 Load: 23.0 t ADT: 1,120

ABBE HILLS RD

Good

Over: STREAM

2T82NR5W, Linn, IA

Built 2016 Load: 23.0 t ADT: 108

PIERCE AVE

Good

Over: W BR MILL CREEK

096412902, O'Brien, IA

Built 1966 Load: 23.0 t ADT: 15

FM

Good

Over: WHITE OAK CREEK

081230904, Polk, IA

Built 1969 Load: 23.0 t ADT: 660

LOCAL

Good

Over: MASQUITO CREEK

076433607, Pottawattamie, IA

Built 2004 Load: 23.0 t ADT: 170

1700TH ST

Good

Over: LYONS CREEK

801439, Shelby, IA

Built 2016 Load: 23.0 t ADT: 35

LOCAL

Good

Over: DEER CREEK

088462703, Woodbury, IA

Built 2007 Load: 23.0 t ADT: 40

34TH ST

Good

Over: STREAM

P61450550, Polk, IA

Built 1990 Load: 23.1 t ADT: 651

LOCAL

Good

Over: ABES FORK

082152901, Tama, IA

Built 2001 Load: 23.1 t ADT: 29

LOCAL

Good

Over: STREAM

072291104, Union, IA

Built 2004 Load: 23.1 t ADT: 5

G67 330TH ST

Good

Over: STREAM

074303403, Adair, IA

Built 2003 Load: 23.2 t ADT: 15

LOCAL

Good

Over: WALNUT CREEK

069192302, Appanoose, IA

Built 2006 Load: 23.2 t ADT: 11

LOCAL

Good

Over: UNNAMED STREAM

070162204, Appanoose, IA

Built 2008 Load: 23.2 t ADT: 11

FM

Good

Over: WILLOW CREEK

083331101, Carroll, IA

Built 2004 Load: 23.2 t ADT: 26

230TH ST

Good

Over: STREAM

080010801, Cedar, IA

Built 2007 Load: 23.2 t ADT: 60

FM

Good

Over: FOX RIVER

068103404, Van Buren, IA

Built 1985 Load: 23.2 t ADT: 45

250TH ST

Good

Over: STREAM

093042301, Clayton, IA

Built 1999 Load: 23.3 t ADT: 206

E AVE

Good

Over: OTTER CREEK

085392501, Crawford, IA

Built 2015 Load: 23.3 t ADT: 82

R AVE

Good

Over: BR VOLGA RIVER

094092904, Fayette, IA

Built 2007 Load: 23.3 t ADT: 471

200TH ST

Good

Over: N BR VOLGA RIVER

094093101, Fayette, IA

Built 2006 Load: 23.3 t ADT: 44

FM

Good

Over: UPHAM'S SLOUGH CREEK

097152102, Floyd, IA

Built 1968 Load: 23.3 t ADT: 1,021

US 20 WB ON RAMP

Good

Over: BEAVER CREEK

0.1 MILE W OF JCT SR T19, Grundy, IA

Built 2003 Load: 23.3 t ADT: 340

150TH AVE

Good

Over: SOUTH FORK ENGLISH RIVER

077131204, Keokuk, IA

Built 2018 Load: 23.3 t ADT: 15

IA 22

Good

Over: DRAINAGE DITCH

1.0 mi. W of SR Y26, Muscatine, IA

Built 1984 Load: 23.3 t ADT: 1,730

IA 3

Good

Over: STREAM

0.9 mi. W of Jct. SR L12, Plymouth, IA

Built 1994 Load: 23.3 t ADT: 3,820

JUNIPER RD

Good

Over: LYONS CREEK

801139, Shelby, IA

Built 2016 Load: 23.3 t ADT: 11

GINKGO RD

Good

Over: SMALL STREAM

803039, Shelby, IA

Built 2015 Load: 23.3 t ADT: 46

LOCAL

Good

Over: CREEK

069110104, Van Buren, IA

Built 2001 Load: 23.3 t ADT: 11

US 65 & 69

Good

Over: SOUTH RIVER OVERFLOW

1.7 mi. S of IA 92, Warren, IA

Built 2011 Load: 23.3 t ADT: 5,400

290TH ST

Good

Over: STREAM

086440701, Woodbury, IA

Built 2002 Load: 23.3 t ADT: 60

Showing 9,401-9,450 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.