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: SOUTH WHITE BREAST CREEK

071240804, Clarke, IA

Built 1982 Load: 7.6 t ADT: 34

LCL-APPLEWOOD

Fair

Over: FARM CR

073400101, Mills, IA

Built 1968 Load: 7.6 t ADT: 15

LOCAL

Fair

Over: MIDDLE RIVER

077312703, Adair, IA

Built 1959 Load: 7.7 t ADT: 11

Ag and DNR Traffic

Fair

Over: Red Rock Pool

Marion Co.; S30, T76, R19, Marion, IA

Built 1920 Load: 7.8 t ADT: 10

LOCAL

Fair

Over: TRIB COATES CR

069083103, Van Buren, IA

Built 1975 Load: 7.8 t ADT: 51

LOCAL

Fair

Over: STREAM

089440102, Woodbury, IA

Built 1950 Load: 7.8 t ADT: 11

LOCAL

Fair

Over: SMALL STREAM

071303501, Union, IA

Built 1940 Load: 7.9 t ADT: 11

HOME ENT (SDB)

Fair

Over: PANTHER CREEK

091012903, Clayton, IA

Built 1920 Load: 8.1 t ADT: 10

LOCAL

Fair

Over: N FORK BUFFALO CREEK

098260202, Winnebago, IA

Built 2001 Load: 8.1 t ADT: 30

FM

Fair

Over: N FORK BUFFALO CREEK

098260701, Winnebago, IA

Built 2006 Load: 8.1 t ADT: 26

460TH ST

Fair

Over: DRAINAGE DITCH

099240201, Winnebago, IA

Built 2005 Load: 8.1 t ADT: 62

LOCAL

Fair

Over: SOLDIER RIVER

085410903, Crawford, IA

Built 1951 Load: 8.2 t ADT: 21

FIELD ENTRANCE

Fair

Over: ROAD DITCH

082232703, Story, IA

Built 1957 Load: 8.2 t ADT: 10

LOCAL

Fair

Over: CREEK

096101401, Winneshiek, IA

Built 1968 Load: 8.2 t ADT: 39

ECHO VALLEY RD.

Fair

Over: OTTER CR

094073003, Fayette, IA

Built 1974 Load: 8.3 t ADT: 78

FM DALE AVE

Fair

Over: STREAM

100142202, Howard, IA

Built 1987 Load: 8.4 t ADT: 707

SW 360TH ST

Fair

Over: N BR OLD MANS CR

079080801, Johnson, IA

Built 1915 Load: 8.5 t ADT: 35

LOCAL

Fair

Over: CREEK

096101303, Winneshiek, IA

Built 1965 Load: 8.5 t ADT: 59

OSAGE TRAIL

Fair

Over: WILLOW RIVER

081422907, Harrison, IA

Built 1977 Load: 8.6 t ADT: 5

LOCAL

Fair

Over: MOFFAT BRANCH

071182104, Monroe, IA

Built 1948 Load: 8.7 t ADT: 40

LOCAL

Fair

Over: WALNUT CREEK

069292901, Ringgold, IA

Built 1946 Load: 8.7 t ADT: 11

LOCAL

Fair

Over: STREAM

096322101, Palo Alto, IA

Built 1914 Load: 8.8 t ADT: 30

LOCAL

Fair

Over: STREAM

074323601, Adair, IA

Built 1961 Load: 9.0 t ADT: 15

LOCAL - CR CRK

Fair

Over: CROOKED CREEK

077351204, Cass, IA

Built 1977 Load: 9.0 t ADT: 11

Ag and DNR Traffic

Fair

Over: Red Rock Pool Channel

Marion Co., S22,T77N,R21, Marion, IA

Built 1955 Load: 9.0 t ADT: 30

LOCAL - 640TH

Fair

Over: CREEK

075363502, Cass, IA

Built 1900 Load: 9.1 t ADT: 30

LOCAL

Fair

Over: SOUTH OTTER CREEK

072240206, Clarke, IA

Built 1982 Load: 9.2 t ADT: 11

PLANT ROAD K

Fair

Over: SPRING CREEK

APPROX. 10,000' E. RD. H, Des Moines, IA

Built 1910 Load: 9.2 t ADT: 5

1250 160TH ST

Fair

Over: WEST IOWA RIVER

094240601, Hancock, IA

Built 1977 Load: 9.2 t ADT: 30

LOCAL

Fair

Over: LOCAL CREEK

073261005, Clarke, IA

Built 1900 Load: 9.3 t ADT: 20

FM

Fair

Over: S FORK ENGLISH RIVER

077101704, Keokuk, IA

Built 1954 Load: 9.3 t ADT: 15

FM

Fair

Over: SMALL UN-NAMED CREEK

097391101, O'Brien, IA

Built 1996 Load: 9.3 t ADT: 30

LOCAL

Fair

Over: STREAM

068090108, Van Buren, IA

Built 1968 Load: 9.3 t ADT: 35

FM

Fair

Over: CHARITON RIVER

070223404, Wayne, IA

Built 1959 Load: 9.3 t ADT: 70

LOCAL ROAD

Fair

Over: CREEK

099091902, Winneshiek, IA

Built 1939 Load: 9.3 t ADT: 59

LOCAL

Fair

Over: STREAM

089430201, Woodbury, IA

Built 2005 Load: 9.3 t ADT: 26

LOCAL

Fair

Over: SMALL STREAM

082373602, Crawford, IA

Built 1965 Load: 9.4 t ADT: 11

LOCAL

Fair

Over: SMALL STREAM

089372202, Sac, IA

Built 1917 Load: 9.4 t ADT: 26

SWALLOW

Fair

Over: SHELLROCK RIVER TRIB

098191803, Worth, IA

Built 1917 Load: 9.4 t ADT: 35

LOCAL

Fair

Over: TROUBLESOME CREEK

078340404, Audubon, IA

Built 1925 Load: 9.5 t ADT: 46

LOCAL

Fair

Over: W FK W NISHNABOTNA RIVER

083373201, Crawford, IA

Built 1942 Load: 9.5 t ADT: 15

MANTI PARK

Fair

Over: UNNAMED CREEK

69403601, Fremont, IA

Built 1940 Load: 9.5 t

MALDEN TRAIL

Fair

Over: ALLEN CREEK

080430404, Harrison, IA

Built 1940 Load: 9.5 t ADT: 40

FM

Fair

Over: STREAM

086363501, Sac, IA

Built 1923 Load: 9.6 t ADT: 15

LOCAL ROAD

Fair

Over: CREEK

100101603, Winneshiek, IA

Built 1964 Load: 9.8 t ADT: 20

LOCAL

Fair

Over: BUFFALO CREEK

084392101, Crawford, IA

Built 1962 Load: 9.9 t ADT: 15

LOCAL ROAD

Fair

Over: LOCAL STREAM

073052704, Henry, IA

Built 1917 Load: 9.9 t ADT: 21

LOCAL

Fair

Over: YELLOW RIVER

096061702, Allamakee, IA

Built 1953 Load: 10.0 t ADT: 108

LOCAL DUGAN AVE

Fair

Over: LIME CR

087103404, Buchanan, IA

Built 1952 Load: 10.0 t ADT: 196

160TH ST

Fair

Over: STREAM

082013410, Cedar, IA

Built 1955 Load: 10.0 t ADT: 120

Showing 1,101-1,150 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.