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

Fair

Over: SMALL CREEK

099121202, Howard, IA

Built 1983 Load: 28.5 t ADT: 73

LOCAL

Fair

Over: SMALL CREEK

086E40403, Jackson, IA

Built 1977 Load: 28.5 t ADT: 279

LOCAL

Fair

Over: STREAM

076100201, Keokuk, IA

Built 1971 Load: 28.5 t ADT: 11

LOC 110TH AVE

Fair

Over: FOUR MILE CREEK

095293404, Kossuth, IA

Built 1987 Load: 28.5 t ADT: 11

US 63

Fair

Over: SOUTH SKUNK RIVER

4.2 MI. N OF JCT. IA 92, Mahaska, IA

Built 1979 Load: 28.5 t ADT: 3,250

FM

Fair

Over: IOWA RIVER

084190205, Marshall, IA

Built 1985 Load: 28.5 t ADT: 69

IA 3

Fair

Over: STREAM

2.5 MI. E of US 75 (Bus.), Plymouth, IA

Built 1994 Load: 28.5 t ADT: 3,820

FM

Fair

Over: MUD CREEK

078222705, Polk, IA

Built 1968 Load: 28.5 t ADT: 796

FM

Fair

Over: SMALL STREAM

080151202, Poweshiek, IA

Built 1969 Load: 28.5 t ADT: 100

FM

Fair

Over: STREAM

069281701, Ringgold, IA

Built 1963 Load: 28.5 t ADT: 34

FM

Fair

Over: GRAND RIVER

071301301, Union, IA

Built 1979 Load: 28.5 t ADT: 89

LOCAL

Fair

Over: STREAM

068192505, Appanoose, IA

Built 1993 Load: 28.6 t ADT: 11

LOCAL

Fair

Over: CREEK

081341702, Audubon, IA

Built 1987 Load: 28.6 t ADT: 46

FM

Fair

Over: W BR BUFFALO CREEK

090081604, Buchanan, IA

Built 1974 Load: 28.6 t ADT: 344

LOCAL

Fair

Over: COLD WATER CREEK

093170702, Butler, IA

Built 1976 Load: 28.6 t ADT: 51

FM

Fair

Over: DD 9-13

088322001, Calhoun, IA

Built 1973 Load: 28.6 t ADT: 20

LOCAL

Fair

Over: DD NO 12

089312702, Calhoun, IA

Built 1973 Load: 28.6 t ADT: 45

FM

Fair

Over: LITTLE TURKEY RIVER

097113201, Chickasaw, IA

Built 1965 Load: 28.6 t ADT: 511

FM

Fair

Over: OTTER CREEK

072250302, Clarke, IA

Built 1983 Load: 28.6 t ADT: 26

190TH AVE

Fair

Over: WILLOW CREEK

094370302, Clay, IA

Built 1978 Load: 28.6 t ADT: 72

LOCAL

Fair

Over: CREEK

100382403, Dickinson, IA

Built 1978 Load: 28.6 t ADT: 81

CALONDER RD

Fair

Over: MIDDLE MAQUOKETA RIVER

090E13106, Dubuque, IA

Built 1974 Load: 28.6 t ADT: 160

FM

Fair

Over: MIDDLE FORK BEAVER CREEK

089182502, Grundy, IA

Built 1978 Load: 28.6 t ADT: 953

FM

Fair

Over: DRAINAGE DITCH

088263102, Hamilton, IA

Built 1924 Load: 28.6 t ADT: 50

FM 570 120TH ST

Fair

Over: BOONE RIVER

094262601, Hancock, IA

Built 1979 Load: 28.6 t ADT: 439

FM & TOLEDO AVE

Fair

Over: PICAYUNE CREEK

080410304, Harrison, IA

Built 1977 Load: 28.6 t ADT: 60

FM

Fair

Over: CREEK

072102103, Jefferson, IA

Built 1973 Load: 28.6 t ADT: 810

FM

Fair

Over: COON CREEK

072110403, Jefferson, IA

Built 1986 Load: 28.6 t ADT: 110

WB I-80

Fair

Over: CIC RAILWAY

3.0 mi. E of jct. I-380, Johnson, IA

Built 1963 Load: 28.6 t ADT: 30,600

JOHNSON-IOWA RD

Fair

Over: BRANCH TO CLEAR CREEK

080081902, Johnson, IA

Built 1979 Load: 28.6 t ADT: 61

LOCAL

Fair

Over: GRAND RIVER

074292105, Madison, IA

Built 1979 Load: 28.6 t ADT: 5

FM

Fair

Over: MITCHELL CREEK

076160905, Mahaska, IA

Built 1972 Load: 28.6 t ADT: 290

FM K-64

Fair

Over: DRAINAGE

090441702, Plymouth, IA

Built 1973 Load: 28.6 t ADT: 110

LOCAL

Fair

Over: SO LIZARD CR - DD 22

090312802, Pocahontas, IA

Built 1972 Load: 28.6 t ADT: 50

LOCAL

Fair

Over: LITTLE CEDAR CR

090340902, Pocahontas, IA

Built 1975 Load: 28.6 t ADT: 26

LOCAL

Fair

Over: N LIZARD CREEK DD #171

091311502, Pocahontas, IA

Built 1975 Load: 28.6 t ADT: 11

FM

Fair

Over: NO LIZARD CK DD #171

091312302, Pocahontas, IA

Built 1979 Load: 28.6 t ADT: 26

LOCAL

Fair

Over: BEAVER CREEK

093312901, Pocahontas, IA

Built 1978 Load: 28.6 t ADT: 20

FM

Fair

Over: STREAM

081152501, Poweshiek, IA

Built 2000 Load: 28.6 t ADT: 45

LOCAL

Fair

Over: BRANCH SALT CREEK

084130602, Tama, IA

Built 1960 Load: 28.6 t ADT: 26

LOCAL

Fair

Over: MUD CREEK

089452403, Woodbury, IA

Built 1978 Load: 28.6 t ADT: 60

N DIVISION ST

Fair

Over: BLUE GRASS CREEK

Fairgrounds, Audubon, IA

Built 1933 Load: 28.7 t

LOCAL

Fair

Over: MAYNES CREEK

091181702, Butler, IA

Built 1900 Load: 28.7 t ADT: 25

W AVE

Fair

Over: DRY RUN CREEK

095102104, Fayette, IA

Built 1954 Load: 28.7 t ADT: 668

FM ADDISON AVE

Fair

Over: WAPSIPINICON RIVER

099141802, Howard, IA

Built 1968 Load: 28.7 t ADT: 285

KEYSTONE

Fair

Over: UNNAMED TRIB TO MAPLE RV

088403504, Ida, IA

Built 2011 Load: 28.7 t ADT: 80

FM

Fair

Over: EMERY CREEK

098450101, Lyon, IA

Built 1977 Load: 28.7 t ADT: 818

IA 92

Fair

Over: SILVER CREEK

2.8 mi. E of Treynor, Pottawattamie, IA

Built 1955 Load: 28.7 t ADT: 2,920

LOCAL

Fair

Over: STREAM

070100704, Van Buren, IA

Built 2006 Load: 28.7 t ADT: 113

FM-130TH STREET

Fair

Over: SIN CREEK

073351901, Adams, IA

Built 1958 Load: 28.8 t ADT: 20

Showing 5,101-5,150 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.