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 230TH ST

Fair

Over: PINE CR

088080901, Buchanan, IA

Built 2007 Load: 20.4 t ADT: 59

FM

Fair

Over: MALONE CREEK

089092406, Buchanan, IA

Built 2003 Load: 20.4 t ADT: 88

FM

Fair

Over: STREAM

090091003, Buchanan, IA

Built 1972 Load: 20.4 t ADT: 658

LOCAL

Fair

Over: ELK RUN CREEK

085340502, Carroll, IA

Built 1975 Load: 20.4 t ADT: 29

COUNTY ROAD

Fair

Over: MIDDLE RACCOON RIVER

079293006, Dallas, IA

Built 1975 Load: 20.4 t ADT: 62

OAK RD

Fair

Over: O'DELL BRANCH

090041603, Delaware, IA

Built 1964 Load: 20.4 t ADT: 59

LOCAL RD

Fair

Over: FLOOD CREEK

095172302, Floyd, IA

Built 1994 Load: 20.4 t ADT: 20

280 TH

Fair

Over: STREAM

082310401, Greene, IA

Built 1947 Load: 20.4 t ADT: 30

110 TH

Fair

Over: STREAM

085300901, Greene, IA

Built 1961 Load: 20.4 t ADT: 11

LOCAL

Fair

Over: BRUSHY CREEK

080320601, Guthrie, IA

Built 1976 Load: 20.4 t ADT: 11

LOCAL 70TH ST

Fair

Over: NORTH TURKEY

099121003, Howard, IA

Built 1966 Load: 20.4 t ADT: 30

LOCAL

Fair

Over: DD

093271402, Humboldt, IA

Built 1960 Load: 20.4 t ADT: 34

LOCAL

Fair

Over: CREEK

084E10901, Jackson, IA

Built 1950 Load: 20.4 t ADT: 49

LOCAL

Fair

Over: BEAR CREEK

084E13103, Jackson, IA

Built 1983 Load: 20.4 t ADT: 25

FM

Fair

Over: BRUSH CREEK

085E43205, Jackson, IA

Built 1980 Load: 20.4 t ADT: 50

LOC 280TH ST

Fair

Over: E FORK DES MOINES RIVER

096280601, Kossuth, IA

Built 1976 Load: 20.4 t ADT: 50

FM 140TH AVE

Fair

Over: E FORK DES MOINES RIVER

096281704, Kossuth, IA

Built 1978 Load: 20.4 t ADT: 80

FIELD ENTRANCE

Fair

Over: SIDE DITCH

075270806, Madison, IA

Built 1940 Load: 20.4 t ADT: 10

LOCAL RD

Fair

Over: MIDDLE RIVER

075281706, Madison, IA

Built 1976 Load: 20.4 t ADT: 26

FM

Fair

Over: WHITE BREAST CREEK

074210301, Marion, IA

Built 1955 Load: 20.4 t ADT: 110

FM

Fair

Over: SMALL UN-NAMED CREEK

095391901, O'Brien, IA

Built 1939 Load: 20.4 t ADT: 50

FM

Fair

Over: OCHEYEDAN RIVER OVERFLOW

097391201, O'Brien, IA

Built 1951 Load: 20.4 t ADT: 20

LOCAL

Fair

Over: FLOYD RIVER

097412303, O'Brien, IA

Built 2009 Load: 20.4 t ADT: 15

230TH STREET

Fair

Over: SOUTH BRANCH

068371303, Page, IA

Built 1999 Load: 20.4 t ADT: 5

LOCAL

Fair

Over: STREAM

067300301, Ringgold, IA

Built 1992 Load: 20.4 t ADT: 20

JUNIPER RD

Fair

Over: SMALL STREAM

078390906, Shelby, IA

Built 1950 Load: 20.4 t ADT: 72

LOCAL

Fair

Over: SNAKE CREEK

081381906, Shelby, IA

Built 1998 Load: 20.4 t ADT: 15

FM

Fair

Over: TRIB DES MOINES R

068081503, Van Buren, IA

Built 1973 Load: 20.4 t ADT: 50

NB/WB IA 5

Fair

Over: MIDDLE RIVER

1.7 mi. N of jct. IA 23, Warren, IA

Built 1966 Load: 20.4 t ADT: 5,650

LOCAL ROAD

Fair

Over: SOUTH RIVER

075230502, Warren, IA

Built 1971 Load: 20.4 t ADT: 360

FM

Fair

Over: MIDDLE RIVER

076252802, Warren, IA

Built 1971 Load: 20.4 t ADT: 180

LOCAL

Fair

Over: BR RACCOON RIVER

091350602, Buena Vista, IA

Built 1977 Load: 20.5 t ADT: 30

LOCAL - UPLAND

Fair

Over: THREEMILE CREEK

074361303, Cass, IA

Built 1996 Load: 20.5 t ADT: 15

LOCAL

Fair

Over: CREEK

096111301, Chickasaw, IA

Built 1952 Load: 20.5 t ADT: 49

LOCAL ROAD

Fair

Over: FOUR MILE CREEK

081241601, Polk, IA

Built 1926 Load: 20.5 t ADT: 26

FM

Fair

Over: STREAM

068290302, Ringgold, IA

Built 1991 Load: 20.5 t ADT: 60

LOCAL

Fair

Over: SMALL STREAM

094442101, Sioux, IA

Built 1936 Load: 20.5 t ADT: 71

LOCAL

Fair

Over: SMALL STREAM

094442901, Sioux, IA

Built 1936 Load: 20.5 t ADT: 34

LOCAL

Fair

Over: SMALL STREAM

094450602, Sioux, IA

Built 1938 Load: 20.5 t ADT: 30

LOCAL

Fair

Over: SMALL STREAM

094452002, Sioux, IA

Built 1977 Load: 20.5 t ADT: 30

LOCAL

Fair

Over: SMALL STREAM

094452202, Sioux, IA

Built 1934 Load: 20.5 t ADT: 20

LOCAL

Fair

Over: SMALL STREAM

094452501, Sioux, IA

Built 1936 Load: 20.5 t ADT: 11

LOCAL

Fair

Over: SMALL STREAM

094460902, Sioux, IA

Built 1954 Load: 20.5 t ADT: 11

LOCAL

Fair

Over: SMALL STREAM

094462901, Sioux, IA

Built 1974 Load: 20.5 t ADT: 40

LOCAL

Fair

Over: SMALL STREAM

094470302, Sioux, IA

Built 1977 Load: 20.5 t ADT: 34

LOCAL

Fair

Over: SMALL STREAM

094472601, Sioux, IA

Built 1969 Load: 20.5 t ADT: 34

LOCAL

Fair

Over: SMALL

095430101, Sioux, IA

Built 1978 Load: 20.5 t ADT: 34

FM

Fair

Over: SMALL STREAM

095433301, Sioux, IA

Built 1983 Load: 20.5 t ADT: 26

LOCAL

Fair

Over: SMALL STREAM

095443001, Sioux, IA

Built 1978 Load: 20.5 t ADT: 60

LOCAL

Fair

Over: STREAM

095461902, Sioux, IA

Built 1981 Load: 20.5 t ADT: 20

Showing 2,701-2,750 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.