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

FM

Good

Over: BLACK HAWK CREEK

088152401, Grundy, IA

Built 1998 Load: 44.7 t ADT: 108

E KELLY AVE

Good

Over: SOLDIER RIVER

080440706, Harrison, IA

Built 2013 Load: 44.7 t ADT: 60

X AVE

Good

Over: GOOSE CREEK

076052805, Louisa, IA

Built 2021 Load: 44.7 t ADT: 62

FM

Good

Over: BNSF RR

098462201, Lyon, IA

Built 2003 Load: 44.7 t ADT: 698

J40 B AVE

Good

Over: FISHER CREEK

068390804, Page, IA

Built 2017 Load: 44.7 t ADT: 150

TAMARACK AVE

Good

Over: LITTLE SIOUX RIVER

904301021002, Plymouth, IA

Built 2017 Load: 44.7 t ADT: 26

FM RD F32

Good

Over: E BRANCH W. NISH. RIVER

802337, Shelby, IA

Built 2001 Load: 44.7 t ADT: 29

US 75

Good

Over: BURR OAK CREEK

3.1 mi N of N jct US 18, Sioux, IA

Built 2011 Load: 44.7 t ADT: 2,610

LOCAL

Good

Over: FLOYD RIVER

095431601, Sioux, IA

Built 2001 Load: 44.7 t ADT: 26

230TH AVE

Good

Over: BEAR CREEK

072153302, Wapello, IA

Built 2019 Load: 44.7 t ADT: 45

LOCAL ROAD

Good

Over: CREEK

098082702, Winneshiek, IA

Built 2008 Load: 44.7 t ADT: 323

FM

Good

Over: LITTLE WALNUT CREEK

069180104, Appanoose, IA

Built 2007 Load: 44.8 t ADT: 760

FM

Good

Over: ROCK CREEK

080031106, Cedar, IA

Built 1996 Load: 44.8 t ADT: 1,660

FM- 510TH ST

Good

Over: WILLOW CREEK

090410701, Cherokee, IA

Built 1998 Load: 44.8 t ADT: 240

FM

Good

Over: LITTLE TURKEY RIVER

096111405, Chickasaw, IA

Built 1995 Load: 44.8 t ADT: 157

FM

Good

Over: SOUTH BIG CREEK

071050603, Henry, IA

Built 1999 Load: 44.8 t ADT: 960

FM

Good

Over: BRIDGE CREEK

076122614, Keokuk, IA

Built 1997 Load: 44.8 t ADT: 190

J-20/140TH ST

Good

Over: EAST TARKIO RIVER

070372903, Page, IA

Built 2005 Load: 44.8 t ADT: 687

FM

Good

Over: INDIAN CREEK

074080710, Washington, IA

Built 1997 Load: 44.8 t ADT: 90

150 TH

Good

Over: WEST BUTTRICKS CREEK

085303401, Greene, IA

Built 1989 Load: 44.9 t ADT: 21

US 61 SB

Good

Over: FARMERS CREEK

0.6 MI. N of Jct. SR E17, Jackson, IA

Built 1996 Load: 44.9 t ADT: 4,050

NB I-29

Good

Over: DRAINAGE DITCH

4.3 mi. S of S Jct. US 34, Mills, IA

Built 2009 Load: 44.9 t ADT: 6,850

SB I-29

Good

Over: ST MARYS CREEK

0.9 mi. S of Jct. IA 370, Mills, IA

Built 2009 Load: 44.9 t ADT: 9,850

320TH ST

Good

Over: STREAM

74331939, Adair, IA

Built 2014 Load: 45.0 t ADT: 11

G35 (190TH ST)

Good

Over: STREAM

76321960, Adair, IA

Built 2013 Load: 45.0 t ADT: 50

N77 KENT AVE

Good

Over: NODAWAY RIVER

1.2 mi S of G35 on N77, Adair, IA

Built 2016 Load: 45.0 t ADT: 29

LEWIS AVE

Good

Over: NORTH TURKEY CREEK

0.9 mi S of G15 on Lewis, Adair, IA

Built 2018 Load: 45.0 t ADT: 30

140TH ST

Good

Over: NORTH TURKEY CREEK

1.9 mi W of 25 on 140th, Adair, IA

Built 2018 Load: 45.0 t ADT: 21

E GRESHAM RD

Good

Over: CRANE CREEK

90-12-10-01-10, Black Hawk, IA

Built 2021 Load: 45.0 t ADT: 29

INDIGO AVE

Good

Over: CALMUS CREEK

Indigo 745 N of 300th, Cerro Gordo, IA

Built 2020 Load: 45.0 t ADT: 35

B64 AGATE RD

Good

Over: STREAM

0.5 miles E Bugle Rd, Clayton, IA

Built 2018 Load: 45.0 t ADT: 295

223RD AVE

Good

Over: SMALL CREEK

081E33004, Clinton, IA

Built 2022 Load: 45.0 t ADT: 41

GRAND AVE

Good

Over: JOHNSON CREEK

Grand Ave o JohnsonCreek, Dallas, IA

Built 2023 Load: 45.0 t ADT: 289

H38 MEDIAPOLIS RD

Good

Over: CEDAR FORK

072033103, Des Moines, IA

Built 2020 Load: 45.0 t ADT: 1,080

US 61 SB

Good

Over: N FORK MAQUOKETA RIVER

5.4 mi. N of Jct. IA 64, Jackson, IA

Built 1996 Load: 45.0 t ADT: 4,050

L16

Good

Over: ELK CREEK

082431504, Monona, IA

Built 2020 Load: 45.0 t ADT: 170

LOCAL

Good

Over: WOLF CREEK

097421901, O'Brien, IA

Built 1991 Load: 45.0 t ADT: 26

120TH ST

Good

Over: DRAINAGE

93-48-13-01-10-40, Plymouth, IA

Built 2013 Load: 45.0 t ADT: 26

2200TH ST

Good

Over: ELK CREEK

081371901, Shelby, IA

Built 2016 Load: 45.0 t ADT: 62

LOCAL

Good

Over: SMALL

095451004, Sioux, IA

Built 2004 Load: 45.0 t ADT: 2,324

FM

Good

Over: LITTLE SOAP CREEK

071152004, Wapello, IA

Built 1999 Load: 45.0 t ADT: 60

170TH ST

Good

Over: WOLF CREEK

088440801, Woodbury, IA

Built 2019 Load: 45.0 t ADT: 5

K64 HASKELL AVE

Good

Over: STREAM

089442904, Woodbury, IA

Built 2020 Load: 45.0 t ADT: 429

350TH STREET

Good

Over: DRAINAGE DITCH

0.55 mi. W of Killdeer, Worth, IA

Built 2021 Load: 45.0 t ADT: 10

IA 14

Good

Over: BR W FK CEDAR RIVER

5.3 MI. S OF JCT. IA 3, Butler, IA

Built 1984 Load: 45.1 t ADT: 1,160

215TH AVE.

Good

Over: NORTHFORK WALNUT CREEK

083040304, Jones, IA

Built 1988 Load: 45.1 t ADT: 59

LOC 160TH AVE

Good

Over: LINDNER CREEK

096280302, Kossuth, IA

Built 1998 Load: 45.1 t ADT: 26

LOC 80TH AVE

Good

Over: FOUR MILE CREEK

096293202, Kossuth, IA

Built 1988 Load: 45.1 t ADT: 40

FM 80TH AVE

Good

Over: BUFFALO CREEK

097271102, Kossuth, IA

Built 1999 Load: 45.1 t ADT: 30

LOC 290TH ST

Good

Over: LINDER CREEK

097283603, Kossuth, IA

Built 1988 Load: 45.1 t ADT: 35

Showing 15,051-15,100 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.