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

130TH AVENUE

Fair

Over: YANKEE RUN CREEK

081E11504, Clinton, IA

Built 1968 Load: 30.4 t ADT: 10

250TH AVENUE

Fair

Over: DEEP CREEK

083E32704, Clinton, IA

Built 1968 Load: 30.4 t ADT: 950

LOCAL

Fair

Over: BR LITTLE SOUIX

099370602, Dickinson, IA

Built 1975 Load: 30.4 t ADT: 51

FM

Fair

Over: LITTLE SIOUX RIVER

100373202, Dickinson, IA

Built 1964 Load: 30.4 t ADT: 112

LOCAL

Fair

Over: GRANGER CREEK

088E21227, Dubuque, IA

Built 1975 Load: 30.4 t ADT: 480

LOCAL

Fair

Over: N.FORK MAQUOKETA RIVER

089021901, Dubuque, IA

Built 1967 Load: 30.4 t ADT: 790

FM

Fair

Over: FLOOD CREEK

094161801, Floyd, IA

Built 1969 Load: 30.4 t ADT: 412

300TH ST

Fair

Over: FLOOD CREEK

094163303, Floyd, IA

Built 1964 Load: 30.4 t ADT: 49

LOCAL

Fair

Over: GIZZARD CREEK

095152502, Floyd, IA

Built 1965 Load: 30.4 t ADT: 59

LOCAL

Fair

Over: FLOOD CREEK

096180302, Floyd, IA

Built 1967 Load: 30.4 t ADT: 44

180TH STREET

Fair

Over: OTTER CREEK

092201501, Franklin, IA

Built 1979 Load: 30.4 t ADT: 44

330 AVENUE

Fair

Over: E NISHNABOTNA RIVER

068412102, Fremont, IA

Built 1975 Load: 30.4 t ADT: 180

FM

Fair

Over: TROUBLESOME CREEK

079333101, Guthrie, IA

Built 1979 Load: 30.4 t ADT: 26

LOCAL

Fair

Over: MOSQUITO CREEK

081310104, Guthrie, IA

Built 1968 Load: 30.4 t ADT: 29

296TH ST

Fair

Over: BOYER RIVER

078441203, Harrison, IA

Built 1974 Load: 30.4 t ADT: 577

FM GORDON AVE

Fair

Over: SOLDIER RIVER

080440404, Harrison, IA

Built 1974 Load: 30.4 t ADT: 60

FM-130TH ST

Fair

Over: S BR TURKEY RIVER

098121101, Howard, IA

Built 1973 Load: 30.4 t ADT: 49

FM

Fair

Over: PRAIRIE CREEK

093272305, Humboldt, IA

Built 1968 Load: 30.4 t ADT: 71

FM

Fair

Over: MIDDLE FK ENGLISH RIVER

078112004, Iowa, IA

Built 1970 Load: 30.4 t ADT: 450

LOCAL

Fair

Over: CREEK

084E52902, Jackson, IA

Built 1969 Load: 30.4 t ADT: 71

E 124TH ST S

Fair

Over: SLATER CREEK

079173302, Jasper, IA

Built 1976 Load: 30.4 t ADT: 910

S 44TH AVE W

Fair

Over: RED ROCK CREEK

079211401, Jasper, IA

Built 1975 Load: 30.4 t ADT: 73

FM

Fair

Over: SUGAR CREEK

080171203, Jasper, IA

Built 1979 Load: 30.4 t ADT: 450

LOCAL

Fair

Over: WALNUT CREEK

073091802, Jefferson, IA

Built 1978 Load: 30.4 t ADT: 26

155TH ST.

Fair

Over: BRANCH OF MINERAL CREEK

085022205, Jones, IA

Built 1941 Load: 30.4 t ADT: 11

IA 149

Fair

Over: SO.FORK ENGLISH RIVER

1.3 mi. N of Iowa 22, Keokuk, IA

Built 1987 Load: 30.4 t ADT: 1,760

FM 130TH ST

Fair

Over: E FORK DES MOINES RIVER

094292303, Kossuth, IA

Built 1971 Load: 30.4 t ADT: 628

LOC ORTON RD

Fair

Over: E FORK DES MOINES RIVER

095291106, Kossuth, IA

Built 1973 Load: 30.4 t ADT: 1,307

FM 50TH AVE

Fair

Over: BLACK CAT CREEK

097302302, Kossuth, IA

Built 1972 Load: 30.4 t ADT: 180

LOC 480TH ST

Fair

Over: UNION SLOUGH DITCH

100282701, Kossuth, IA

Built 1975 Load: 30.4 t ADT: 41

FM

Fair

Over: SMALL STREAM

073022906, Louisa, IA

Built 1966 Load: 30.4 t ADT: 110

LOCAL

Fair

Over: INDIAN CREEK

075042401, Louisa, IA

Built 1980 Load: 30.4 t ADT: 35

FM

Fair

Over: MIDDLE CREEK

076151606, Mahaska, IA

Built 1971 Load: 30.4 t ADT: 300

FM T-43

Fair

Over: S SKUNK RIVER

076171206, Mahaska, IA

Built 1977 Load: 30.4 t ADT: 120

LOCAL

Fair

Over: MIDDLE CREEK

077162102, Mahaska, IA

Built 1953 Load: 30.4 t ADT: 30

LOCAL

Fair

Over: STREAM

074202903, Marion, IA

Built 1975 Load: 30.4 t ADT: 62

ATTICA RD

Fair

Over: COMPETINE CREEK

075190712, Marion, IA

Built 1925 Load: 30.4 t ADT: 3,020

FA-315TH ST

Fair

Over: RAINES BRANCH

072413208, Mills, IA

Built 1947 Load: 30.4 t ADT: 1,246

FA-195TH ST

Fair

Over: PONY CREEK

072431602, Mills, IA

Built 1967 Load: 30.4 t ADT: 558

FM

Fair

Over: MONONA HARRISON DD

082442003, Monona, IA

Built 1974 Load: 30.4 t ADT: 100

LOCAL RD

Fair

Over: ENGLISH CREEK

072190904, Monroe, IA

Built 1968 Load: 30.4 t ADT: 11

LOCAL

Fair

Over: DRAINAGE DITCH 13

076020703, Muscatine, IA

Built 1968 Load: 30.4 t ADT: 62

LOCAL

Fair

Over: MUSCATINE SLOUGH

076032403, Muscatine, IA

Built 1975 Load: 30.4 t ADT: 239

FM

Fair

Over: BIG SLOUGH CREEK

078042902, Muscatine, IA

Built 1980 Load: 30.4 t ADT: 40

FM

Fair

Over: DRY RUN

095412702, O'Brien, IA

Built 1961 Load: 30.4 t ADT: 917

FM

Fair

Over: LITTLE FLOYD RIVER

096420610, O'Brien, IA

Built 1963 Load: 30.4 t ADT: 609

LOCAL

Fair

Over: OTTER CREEK

099411808, Osceola, IA

Built 1964 Load: 30.4 t ADT: 50

FM

Fair

Over: CYLINDER CREEK

095322401, Palo Alto, IA

Built 1979 Load: 30.4 t ADT: 31

FM

Fair

Over: DD175

095330401, Palo Alto, IA

Built 1977 Load: 30.4 t ADT: 81

FM

Fair

Over: JOHN'S CREEK

090441201, Plymouth, IA

Built 1971 Load: 30.4 t ADT: 259

Showing 5,651-5,700 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.