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

Fair

Over: SNY MAGILL

094032206, Clayton, IA

Built 1980 Load: 39.5 t ADT: 953

200TH STREET

Fair

Over: BUFFALO CR

092210601, Franklin, IA

Built 1965 Load: 39.5 t ADT: 21

FM

Fair

Over: BIG BEAR CREEK

080110706, Iowa, IA

Built 1995 Load: 39.5 t ADT: 540

LOCAL

Fair

Over: CREEK

086E32603, Jackson, IA

Built 1978 Load: 39.5 t ADT: 50

IA 38

Fair

Over: KITTY CREEK

0.5 MI. N OF JCT. 151, Jones, IA

Built 1973 Load: 39.5 t ADT: 3,630

CHERRY GROVE RD

Fair

Over: WHITE OAK CREEK

083043502, Jones, IA

Built 1978 Load: 39.5 t ADT: 30

FRONT DR.

Fair

Over: OTTER CREEK

084081233, Linn, IA

Built 1990 Load: 39.5 t ADT: 923

220TH AVE

Fair

Over: BR OF CHARITON RIVER

072222504, Lucas, IA

Built 1959 Load: 39.5 t ADT: 187

DURHAM AVE

Fair

Over: NORTH SKUNK RIVER

082201006, Marshall, IA

Built 1973 Load: 39.5 t ADT: 113

FM

Fair

Over: CEDAR RIVER

076040203, Muscatine, IA

Built 1997 Load: 39.5 t ADT: 550

LOCAL NE 54TH

Fair

Over: FOUR MILE CREEK

080240100, Polk, IA

Built 1990 Load: 39.5 t ADT: 1,377

US 65

Fair

Over: DRAINAGE DITCH

2.8 MI. N OF JCT. IA 2, Wayne, IA

Built 1976 Load: 39.5 t ADT: 1,050

FM

Fair

Over: LIZARD CREEK

090301804, Webster, IA

Built 1971 Load: 39.5 t ADT: 20

LOCAL

Fair

Over: MUD CREEK

082101201, Benton, IA

Built 1990 Load: 39.6 t ADT: 14

FM

Fair

Over: MUD CREEK

084100703, Benton, IA

Built 1989 Load: 39.6 t ADT: 60

LOCAL

Fair

Over: IOWAY CREEK

085250501, Boone, IA

Built 1988 Load: 39.6 t ADT: 20

IA 281

Fair

Over: LITTLE WAPSIPINICON RVR

0.2 mi. E of SR V62, Buchanan, IA

Built 1954 Load: 39.6 t ADT: 2,670

LOCAL

Fair

Over: TWO MILE CREEK

094141101, Chickasaw, IA

Built 1977 Load: 39.6 t ADT: 25

LOCAL

Fair

Over: LITTLE TURKEY

096112305, Chickasaw, IA

Built 1978 Load: 39.6 t ADT: 47

LOCAL

Fair

Over: LITTLE SIOUX RIVER

100372903, Dickinson, IA

Built 1989 Load: 39.6 t ADT: 20

FM

Fair

Over: JOHNNY CREEK

074040702, Louisa, IA

Built 1970 Load: 39.6 t ADT: 50

US 61 SB

Fair

Over: S FORK MAQUOKET RIVER

0.5 MI. N OF JCT. IA #64, Jackson, IA

Built 1998 Load: 39.7 t ADT: 5,100

FM

Fair

Over: DRAINAGE

072180805, Monroe, IA

Built 1957 Load: 39.7 t ADT: 80

LOCAL

Fair

Over: BRANCH OF IOWA RIVER

084162305, Tama, IA

Built 2006 Load: 39.7 t ADT: 15

FM

Fair

Over: JORDAN CREEK

070212103, Wayne, IA

Built 1965 Load: 39.7 t ADT: 280

LOCAL - 680TH

Fair

Over: WATERWAY

074352804, Cass, IA

Built 1985 Load: 39.8 t ADT: 5

LOCAL

Fair

Over: LONG CREEK

070042801, Des Moines, IA

Built 1977 Load: 39.8 t ADT: 91

LOCAL

Fair

Over: COTTONWOOD DRAIN

071022501, Des Moines, IA

Built 1992 Load: 39.8 t ADT: 176

LOCAL

Fair

Over: SMALL CREEK

085E22430, Jackson, IA

Built 2001 Load: 39.8 t ADT: 11

IA 182

Fair

Over: STREAM

0.2 mi N of Jct. SR A34, Lyon, IA

Built 1955 Load: 39.8 t ADT: 2,500

E41 LINCOLN HWY

Fair

Over: DYE CREEK

083210701, Story, IA

Built 2001 Load: 39.8 t ADT: 1,048

FM 145 AVE

Fair

Over: PRAIRIE CREEK

089062604, Delaware, IA

Built 1971 Load: 39.9 t ADT: 1,296

100 TH

Fair

Over: HARDIN CREEK

085310203, Greene, IA

Built 1982 Load: 39.9 t ADT: 20

US 18

Fair

Over: WEST FORK IOWA RIVER

2.8 mi. E of SR R35, Hancock, IA

Built 1958 Load: 39.9 t ADT: 5,200

LOCAL

Fair

Over: SMALL STREAM

076050203, Louisa, IA

Built 1989 Load: 39.9 t ADT: 51

US 34 & 65

Fair

Over: OVER BNSF RR

0.1 mi. E of W Jct. US 65, Lucas, IA

Built 1974 Load: 39.9 t ADT: 3,560

FM

Fair

Over: GINGER CREEK

095402901, O'Brien, IA

Built 1928 Load: 39.9 t ADT: 180

FM

Fair

Over: ROCK RIVER

095470603, Sioux, IA

Built 1969 Load: 39.9 t ADT: 139

FM

Fair

Over: STREAM

069111406, Van Buren, IA

Built 1989 Load: 39.9 t ADT: 720

LOCAL

Fair

Over: FITZGERALD CREEK

096073303, Winneshiek, IA

Built 1969 Load: 39.9 t ADT: 33

HUDSON RD

Fair

Over: DRY RUN CREEK

000000000, Black Hawk, IA

Built 1969 Load: 40.0 t ADT: 6,993

SB I-35,WB I-80

Fair

Over: DRAINAGE DITCH

0.8 mi. W of Jct. IA 415, Polk, IA

Built 1958 Load: 40.0 t ADT: 48,000

EB I-80

Fair

Over: SILVER CREEK

5.1 mi. W of Jct. US 59, Pottawattamie, IA

Built 1966 Load: 40.0 t ADT: 12,850

ELK AVE

Fair

Over: STREAM

3.0 mi W of N72 on 330th, Adair, IA

Built 2019 Load: 40.1 t ADT: 30

LOCAL

Fair

Over: DRY RUN CREEK

094160102, Floyd, IA

Built 1983 Load: 40.1 t ADT: 11

NB IA 5 & WB 92

Fair

Over: WHITE BREAST CREEK

2.7 MI. N OF JCT. Iowa 14, Marion, IA

Built 1978 Load: 40.1 t ADT: 4,200

BRIDGE ST

Fair

Over: HONEY CREEK

092052524, Clayton, IA

Built 1973 Load: 40.2 t ADT: 589

FM

Fair

Over: MIDDLE MAQUOKETA RIVER

090E13204, Dubuque, IA

Built 1974 Load: 40.2 t ADT: 350

US 20

Fair

Over: DRAINAGE DITCH #4

1.8 MILES EAST OF US 69, Hamilton, IA

Built 1968 Load: 40.2 t ADT: 9,600

LOCAL

Fair

Over: CREEK

084E71804, Jackson, IA

Built 1998 Load: 40.2 t ADT: 34

Showing 8,151-8,200 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.