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: TWELVE MILE CREEK

086142704, Tama, IA

Built 1978 Load: 22.3 t ADT: 39

LOCAL

Fair

Over: MIDDLE FORK 102 RIVER

068342903, Taylor, IA

Built 1979 Load: 22.3 t ADT: 50

FM

Fair

Over: MIDDLE PLATTE RIVER

071312107, Union, IA

Built 1967 Load: 22.3 t ADT: 15

LOCAL

Fair

Over: WEST PLATTE

072313102, Union, IA

Built 1979 Load: 22.3 t ADT: 79

LOCAL ROAD

Fair

Over: COTTON CREEK

074222804, Warren, IA

Built 1980 Load: 22.3 t ADT: 35

LOCAL ROAD

Fair

Over: COAL CREEK

076222504, Warren, IA

Built 1976 Load: 22.3 t ADT: 11

50TH AVE

Fair

Over: MIDDLE SOUTH CREEK

077250200, Warren, IA

Built 1971 Load: 22.3 t ADT: 144

LOCAL

Fair

Over: BADGER CREEK

077252904, Warren, IA

Built 1978 Load: 22.3 t ADT: 120

25TH ST

Fair

Over: CALEB CREEK

068233204, Wayne, IA

Built 1984 Load: 22.3 t ADT: 10

LOCAL

Fair

Over: GARRETSON DRAINAGE DITCH

086451901, Woodbury, IA

Built 1984 Load: 22.3 t ADT: 30

LOCAL

Fair

Over: EAGLE CREEK

090263605, Wright, IA

Built 1981 Load: 22.3 t ADT: 170

LOCAL

Fair

Over: DD #219

092261202, Wright, IA

Built 1979 Load: 22.3 t ADT: 21

FM

Fair

Over: OTTER CREEK

093253301, Wright, IA

Built 1968 Load: 22.3 t ADT: 41

LOCAL

Fair

Over: BOONE RIVER

093260202, Wright, IA

Built 1983 Load: 22.3 t ADT: 31

FM

Fair

Over: BOONE RIVER

093261001, Wright, IA

Built 1980 Load: 22.3 t ADT: 11

FM

Fair

Over: BOONE RIVER

093261002, Wright, IA

Built 1980 Load: 22.3 t ADT: 31

LOCAL

Fair

Over: TRIB OF TROUBLESOME CRK

078340505, Audubon, IA

Built 1980 Load: 22.4 t ADT: 41

LOCAL RD

Fair

Over: BUFFALO CREEK

089073101, Buchanan, IA

Built 1980 Load: 22.4 t ADT: 123

FM

Fair

Over: HARTER CR

089092702, Buchanan, IA

Built 1963 Load: 22.4 t ADT: 1,169

FM

Fair

Over: DD NO. 1

089331901, Calhoun, IA

Built 1964 Load: 22.4 t ADT: 219

BUCKEYE RD

Fair

Over: WAPSINONOC CREEK

079042907, Cedar, IA

Built 1975 Load: 22.4 t ADT: 120

LOCAL

Fair

Over: SPRING BRANCH

095132603, Chickasaw, IA

Built 2010 Load: 22.4 t ADT: 41

GRAPE RD

Fair

Over: ROBERT CREEK

093052504, Clayton, IA

Built 1946 Load: 22.4 t ADT: 196

170TH AVE

Fair

Over: SMALL STREAM

087050804, Delaware, IA

Built 1992 Load: 22.4 t ADT: 97

LOC 230TH ST

Fair

Over: STREAM

088030801, Delaware, IA

Built 1992 Load: 22.4 t ADT: 39

LOCAL 290 AVE

Fair

Over: SMALL STREAM

090032902, Delaware, IA

Built 1992 Load: 22.4 t ADT: 15

140TH ST

Fair

Over: STREAM

090053001, Delaware, IA

Built 1968 Load: 22.4 t ADT: 5

BACKBONE ST PK

Fair

Over: MAQUOKETA RIVER

IN BACKBONE STATE PARK, Delaware, IA

Built 1934 Load: 22.4 t

LOC ROBIN AVE

Fair

Over: N BRANCH TURKEY RIVER

099122402, Howard, IA

Built 1986 Load: 22.4 t ADT: 135

FM ROBIN AVE

Fair

Over: SOUTH TURKEY

099122504, Howard, IA

Built 1966 Load: 22.4 t ADT: 422

LOCAL

Fair

Over: CREEK

091282802, Humboldt, IA

Built 1900 Load: 22.4 t ADT: 40

LOCAL

Fair

Over: CREEK

086E12801, Jackson, IA

Built 1938 Load: 22.4 t ADT: 45

LOC 420TH ST

Fair

Over: MUD CREEK

099302501, Kossuth, IA

Built 1981 Load: 22.4 t ADT: 11

WB US 30

Fair

Over: CIC RR

0.8 MI. W OF JCT. I-380, Linn, IA

Built 1979 Load: 22.4 t ADT: 15,000

CAMEO AVE

Fair

Over: ROCK CREEK

098180902, Mitchell, IA

Built 1974 Load: 22.4 t ADT: 33

LOCAL SEC RD

Fair

Over: NELSON CR

094412601, O'Brien, IA

Built 1935 Load: 22.4 t ADT: 30

LOCAL SEC RD

Fair

Over: LANGE CREEK

094422306, O'Brien, IA

Built 1954 Load: 22.4 t ADT: 62

LOCAL SEC RD

Fair

Over: WATERMAN CREEK

095392701, O'Brien, IA

Built 1951 Load: 22.4 t ADT: 26

FM

Fair

Over: FLOYD RIVER

097422902, O'Brien, IA

Built 1962 Load: 22.4 t ADT: 518

LOCAL

Fair

Over: JACK CREEK

097332205, Palo Alto, IA

Built 1973 Load: 22.4 t ADT: 73

288TH ST

Fair

Over: CREEK

080E22205, Scott, IA

Built 1966 Load: 22.4 t ADT: 45

2100TH ST

Fair

Over: SMALL STREAM

2100th West of M-16, Shelby, IA

Built 2020 Load: 22.4 t ADT: 30

610TH AVE

Fair

Over: GRANT 5 OPEN DITCH

083232402, Story, IA

Built 1941 Load: 22.4 t ADT: 50

LOCAL

Fair

Over: SMALL CREEK

069092208, Van Buren, IA

Built 1975 Load: 22.4 t ADT: 16

FM

Fair

Over: LITTLE LICK CREEK

070092804, Van Buren, IA

Built 1957 Load: 22.4 t ADT: 35

LOCAL

Fair

Over: BOONE RIVER

092260601, Wright, IA

Built 1985 Load: 22.4 t ADT: 36

QUINCY TRAIL

Fair

Over: KEMP CREEK

072342101, Adams, IA

Built 1977 Load: 22.5 t ADT: 15

LOCAL

Fair

Over: BUCK CREEK

078363201, Audubon, IA

Built 1974 Load: 22.5 t ADT: 30

FM

Fair

Over: CREEK

080361302, Audubon, IA

Built 1930 Load: 22.5 t ADT: 71

INDEPENDENCE RD

Fair

Over: CREEK

076371501, Cass, IA

Built 2005 Load: 22.5 t ADT: 5

Showing 3,351-3,400 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.