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

S55 SPRUCE AVE

Good

Over: SMALL STREAM

91191904100058, Franklin, IA

Built 2019 Load: 39.2 t ADT: 59

IA 14

Good

Over: SNIPE CREEK

1.1 MI. E OF E JCT SR F17, Jasper, IA

Built 2009 Load: 39.2 t ADT: 1,360

IA 14

Good

Over: STREAM

0.2 MI. S OF JCT. 224, Jasper, IA

Built 2017 Load: 39.2 t ADT: 1,360

EB IA 163

Good

Over: WALNUT CREEK

2.4 MI. W OF JCT. IA 117, Jasper, IA

Built 1974 Load: 39.2 t ADT: 5,800

IA 330 SB

Good

Over: MUD CREEK

3.5 MI. N OF JCT. SR F17, Jasper, IA

Built 2002 Load: 39.2 t ADT: 4,750

US 34 WB

Good

Over: CROW CREEK

0.8 mi. E of Jct. Iowa 1, Jefferson, IA

Built 2007 Load: 39.2 t ADT: 2,600

HALF MOON AVE

Good

Over: DEER CREEK

079070504, Johnson, IA

Built 2022 Load: 39.2 t ADT: 143

NB US 151

Good

Over: BIG CREEK

1.9 mi. N of Jct. SR X20, Linn, IA

Built 1992 Load: 39.2 t ADT: 6,500

T54 TIMBER AVE

Good

Over: BEAVER CREEK

0.2 mi N of IA 9, Mitchell, IA

Built 2015 Load: 39.2 t ADT: 49

410TH ST

Good

Over: BEAVER CREEK

0.2 Mi W Timber Ave, Mitchell, IA

Built 2018 Load: 39.2 t ADT: 70

HARRISON ST

Good

Over: INDIAN CREEK CONDUIT

000000000, Pottawattamie, IA

Built 1981 Load: 39.2 t ADT: 4,012

LOCAL

Good

Over: MOSQUITO CREEK

079400305, Shelby, IA

Built 2004 Load: 39.2 t ADT: 51

IRR-FM

Good

Over: OVER UP RR

083152909, Tama, IA

Built 1993 Load: 39.2 t ADT: 619

LOCAL ROAD

Good

Over: TEN MILE CREEK

000000000, Winneshiek, IA

Built 2010 Load: 39.2 t ADT: 49

S62 VINE AVE

Good

Over: DRAINAGE DITCH

Vine Ave at 470th St, Worth, IA

Built 2019 Load: 39.2 t ADT: 59

IA 3

Good

Over: LITTLE EAGLE CREEK

2.9 MI. W OF SR R-38, Wright, IA

Built 2016 Load: 39.2 t ADT: 3,450

FM

Good

Over: ROCK CREEK

081031407, Cedar, IA

Built 1991 Load: 39.3 t ADT: 90

TAFT AVE

Good

Over: BR BUCK CREEK

078052902, Johnson, IA

Built 2016 Load: 39.3 t ADT: 46

JASPER AVE

Good

Over: STREAM

T78N, R7W, 22, Johnson, IA

Built 2018 Load: 39.3 t ADT: 15

COPI RD

Good

Over: CLEAR CREEK

SE1/4 of 30, T-80N, R7W, Johnson, IA

Built 2015 Load: 39.3 t ADT: 42

JOHNSON IA RD

Good

Over: STREAM

NW1/4,30,T80N,R8W, Johnson, IA

Built 2015 Load: 39.3 t ADT: 61

SEVEN SIS RD

Good

Over: HOOSIER CREEK

081060507, Johnson, IA

Built 2005 Load: 39.3 t ADT: 92

LINN-JOHNSON RD

Good

Over: STREAM

081080101, Johnson, IA

Built 2001 Load: 39.3 t ADT: 81

280TH STREET

Good

Over: EAST NODAWAY RIVER

067360604, Page, IA

Built 2002 Load: 39.3 t ADT: 150

LOCAL

Good

Over: W FORK W NISHNABOTNA RVR

081380701, Shelby, IA

Built 1992 Load: 39.3 t ADT: 45

DOGWOOD

Good

Over: WINNEBAGO RIVER

097220304, Cerro Gordo, IA

Built 2006 Load: 39.4 t ADT: 73

306TH ST

Good

Over: LITTLE TURKEY RIVER

095100507, Fayette, IA

Built 1989 Load: 39.4 t ADT: 44

US 18 WB

Good

Over: I&M RR

0.4 mi. E of Jct. SR B35, Floyd, IA

Built 1998 Load: 39.4 t ADT: 4,550

LOCAL

Good

Over: BRUSHY CREEK

081330602, Guthrie, IA

Built 1992 Load: 39.4 t ADT: 29

NORTH 27TH AVE E

Good

Over: NORTH SKUNK RIVER

080182205, Jasper, IA

Built 1992 Load: 39.4 t ADT: 110

LOCAL

Good

Over: N SKUNK RIVER

081193504, Jasper, IA

Built 1984 Load: 39.4 t ADT: 35

US #63

Good

Over: MUCHAKINOCK CREEK

2.4 mi. N of Jct. IA 137, Mahaska, IA

Built 2001 Load: 39.4 t ADT: 6,250

US 63 SB IA 163 EB

Good

Over: MUCHAKINOCK CREEK

2.4 mi. N of Jct. IA 137, Mahaska, IA

Built 2001 Load: 39.4 t ADT: 6,250

US 30 EB

Good

Over: IOWA RIVER

0.9 MI E OF W JCT SR T47, Tama, IA

Built 2005 Load: 39.4 t ADT: 5,850

IA 141

Good

Over: DRAINAGE DITCH

2.2 mi. W of SR K64, Woodbury, IA

Built 2010 Load: 39.4 t ADT: 2,130

LOCAL ROAD

Good

Over: IOWA RIVER

092242501, Wright, IA

Built 1991 Load: 39.4 t ADT: 31

FM

Good

Over: PRAIRIE CREEK

083110601, Benton, IA

Built 2008 Load: 39.5 t ADT: 25

FOULK RD

Good

Over: TRIB TO MILLER CREEK

88-12-20-04-10, Black Hawk, IA

Built 1998 Load: 39.5 t ADT: 39

KILLDEER AVE

Good

Over: QUARTER SECTION RUN

091133502, Bremer, IA

Built 2022 Load: 39.5 t ADT: 49

LOCAL - NSHNA V

Good

Over: NISHNABOTNA RIVER

075371003, Cass, IA

Built 1992 Load: 39.5 t ADT: 82

WASHINGTON AVE

Good

Over: LIZARD CREEK

081011402, Cedar, IA

Built 2023 Load: 39.5 t ADT: 60

310TH ST

Good

Over: STONY CREEK

097382501, Clay, IA

Built 2020 Load: 39.5 t ADT: 26

1ST ST SOUTH

Good

Over: PICKERAL RUN

86351803, Clay, IA

Built 2021 Load: 39.5 t ADT: 171

200TH ST

Good

Over: DD #11

082E12603, Clinton, IA

Built 2004 Load: 39.5 t ADT: 11

160 ST

Good

Over: BROPHY CREEK

082E50403, Clinton, IA

Built 2000 Load: 39.5 t ADT: 41

FM

Good

Over: N FABIUS RIVER

067141010, Davis, IA

Built 1989 Load: 39.5 t ADT: 130

FM 165TH ST

Good

Over: MAQUOKETA RIVER

089060105, Delaware, IA

Built 1994 Load: 39.5 t ADT: 295

EB US 20

Good

Over: BRANCH PLUM CREEK

5.0 MI. E OF JCT. IA 38, Delaware, IA

Built 1981 Load: 39.5 t ADT: 4,850

N 52 490TH AVE

Good

Over: JACK CR DD #17

98321502, Emmet, IA

Built 2019 Load: 39.5 t ADT: 589

N 52 490TH AVE

Good

Over: JACK CREEK

098322204, Emmet, IA

Built 2019 Load: 39.5 t ADT: 549

Showing 14,001-14,050 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.