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

E AVE NW

Good

Over: STREAM

083073001, Linn, IA

Built 1900 Load: 24.5 t ADT: 3,596

430TH

Good

Over: WAPSIPINICON RIVER

099152401, Mitchell, IA

Built 1988 Load: 24.5 t ADT: 78

FM

Good

Over: MILL CREEK

095412001, O'Brien, IA

Built 1985 Load: 24.5 t ADT: 50

IA 3

Good

Over: STREAM

2.0 mi. E of SR K18, Plymouth, IA

Built 1975 Load: 24.5 t ADT: 940

400TH ST

Good

Over: BRANCH IOWA RIVER

081140103, Poweshiek, IA

Built 2014 Load: 24.5 t ADT: 15

FM

Good

Over: BRANCH OF SALT CREEK

084143606, Tama, IA

Built 2002 Load: 24.5 t ADT: 15

LOCAL

Good

Over: GIVEN CREEK

086151307, Tama, IA

Built 2006 Load: 24.5 t ADT: 44

LOCAL

Good

Over: SUGAR CREEK

072132805, Wapello, IA

Built 2015 Load: 24.5 t ADT: 423

176TH PLACE

Good

Over: WALNUT CREEK

074190208, Marion, IA

Built 2021 Load: 24.6 t ADT: 62

IA 175

Good

Over: DRAINAGE DITCH

0.6 mi E of SR L20, Monona, IA

Built 1973 Load: 24.6 t ADT: 970

TIMBER ROAD

Good

Over: WALNUT CREEK

078382602, Shelby, IA

Built 2021 Load: 24.6 t ADT: 21

1250TH ST

Good

Over: TRIB TO MOSQUITO CREEK

079400303, Shelby, IA

Built 2021 Load: 24.6 t ADT: 42

1800TH ST

Good

Over: LYONS CREEK

080391001, Shelby, IA

Built 2022 Load: 24.6 t ADT: 15

MCDONALD BLVD

Good

Over: PERRY CREEK

Dearborn Boulevard over P, Woodbury, IA

Built 2016 Load: 24.6 t ADT: 283

FM

Good

Over: MILL CREEK

082022106, Cedar, IA

Built 2004 Load: 24.7 t ADT: 60

40TH ST

Good

Over: BR STAFF CR

100142601, Howard, IA

Built 2018 Load: 24.7 t ADT: 73

LOCAL 240TH ST

Good

Over: STREAM

091121301, Bremer, IA

Built 2003 Load: 24.8 t ADT: 118

200TH ST

Good

Over: CRANE CREEK

092122901, Bremer, IA

Built 1998 Load: 24.8 t ADT: 20

LOCAL

Good

Over: STREAM

080323001, Guthrie, IA

Built 2005 Load: 24.8 t ADT: 15

LOCAL RD

Good

Over: D D #2

091293001, Humboldt, IA

Built 1978 Load: 24.8 t ADT: 26

NE 126TH AVE

Good

Over: DRAINAGE DITCH

081233603, Polk, IA

Built 2000 Load: 24.8 t ADT: 816

IA 150

Good

Over: STREAM

4.8 MI. S OF JCT. US 52, Winneshiek, IA

Built 1988 Load: 24.8 t ADT: 2,180

LOCAL

Good

Over: GRAND RIVER

075300801, Adair, IA

Built 1958 Load: 24.9 t ADT: 30

FM

Good

Over: PRAIRIE CREEK

082092008, Benton, IA

Built 1986 Load: 24.9 t ADT: 137

MILLER CREEK RD

Good

Over: TRIB TO MILLER CREEK

87-12-05-01-10, Black Hawk, IA

Built 1948 Load: 24.9 t ADT: 39

ULMUS

Good

Over: FILES DITCH

096192910, Cerro Gordo, IA

Built 1953 Load: 24.9 t ADT: 10

GOLDEN AVE

Good

Over: DOE CREEK

091040604, Clayton, IA

Built 2002 Load: 24.9 t ADT: 11

SB US 61

Good

Over: SILVER CREEK

0.5 MI. S OF JCT.US 30, Clinton, IA

Built 1981 Load: 24.9 t ADT: 7,050

150 STREET

Good

Over: WALNUT CREEK

070402703, Fremont, IA

Built 1982 Load: 24.9 t ADT: 40

LOCAL

Good

Over: BIG CEDAR CREEK

071073303, Henry, IA

Built 1978 Load: 24.9 t ADT: 113

IA 175

Good

Over: STREAM

2.2 mi. W of W jct US 59, Ida, IA

Built 2007 Load: 24.9 t ADT: 2,140

IA 175

Good

Over: STREAM

3.2 mi E of E Jct US 59, Ida, IA

Built 1939 Load: 24.9 t ADT: 2,080

130TH ST.

Good

Over: BIG BEAR CREEK

084030501, Jones, IA

Built 1989 Load: 24.9 t ADT: 59

LOCAL

Good

Over: BR OF NORTH CEDAR CREEK

072200601, Lucas, IA

Built 2000 Load: 24.9 t ADT: 21

205TH TRAIL

Good

Over: DR TO LITTLE WHTBRST CR

073213204, Lucas, IA

Built 2017 Load: 24.9 t ADT: 16

M55 J AVE

Good

Over: NISHNABOTNA TRIB

073383502, Montgomery, IA

Built 2003 Load: 24.9 t ADT: 26

LOCAL

Good

Over: STREAM

100422601, Osceola, IA

Built 1991 Load: 24.9 t ADT: 15

IA 140

Good

Over: DRAINAGE

0.5 mi. N of SR C60, Plymouth, IA

Built 2008 Load: 24.9 t ADT: 970

WISTFUL VISTA

Good

Over: JORDAN CREEK

000000000, Polk, IA

Built 1996 Load: 24.9 t ADT: 651

135TH

Good

Over: SIDE DITCH BRIDGE

1.8 MI. S OF IOWA #22, Washington, IA

Built 1993 Load: 24.9 t ADT: 10

E WASHBURN RD

Good

Over: CEDAR RIVER OVERFLOW

88-12-27-01-10, Black Hawk, IA

Built 1979 Load: 25.0 t ADT: 1,571

610 220TH ST

Good

Over: BOONE RIVER

095260101, Hancock, IA

Built 1978 Load: 25.0 t ADT: 26

120TH ST

Good

Over: STREAM

089441503, Woodbury, IA

Built 2006 Load: 25.0 t ADT: 26

W SHAULIS RD

Good

Over: PRESCOTTS CREEK

CITY BRIDGE NO. 51, Black Hawk, IA

Built 1993 Load: 25.1 t ADT: 1,699

NETTLE

Good

Over: BEAVER DAM CREEK

094201702, Cerro Gordo, IA

Built 1985 Load: 25.1 t ADT: 30

JUPITER RD

Good

Over: TURKEY RIVER

092043618, Clayton, IA

Built 1983 Load: 25.1 t ADT: 246

FM SAND RD

Good

Over: STREAM

078060204, Johnson, IA

Built 2005 Load: 25.1 t ADT: 2,620

IA 14

Good

Over: ENGLISH CREEK

1.5 mi. S Jct of IA 5 &92, Marion, IA

Built 1993 Load: 25.1 t ADT: 3,230

LCL-307TH ST

Good

Over: CREEK

073413108, Mills, IA

Built 1998 Load: 25.1 t ADT: 5

340TH

Good

Over: LITTLE CEDAR RIVER

097150501, Mitchell, IA

Built 1981 Load: 25.1 t ADT: 70

Showing 9,551-9,600 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.