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

Poor

Over: STREAM

081150501, Poweshiek, IA

Built 1971 Load: 19.8 t ADT: 11

LOCAL

Poor

Over: STREAM

086361202, Sac, IA

Built 1917 Load: 19.8 t ADT: 30

LOCAL

Poor

Over: SMALL

068353001, Taylor, IA

Built 1979 Load: 19.8 t ADT: 11

380TH

Poor

Over: DRAINAGE DITCH

098221501, Worth, IA

Built 1959 Load: 19.8 t ADT: 20

LOCAL

Poor

Over: STREAM

069163406, Appanoose, IA

Built 1952 Load: 19.9 t ADT: 51

C33

Poor

Over: SMALL STREAM

092152301, Butler, IA

Built 1966 Load: 19.9 t ADT: 1,002

180TH ST

Poor

Over: BEAVER CREEK

085400902, Crawford, IA

Built 2018 Load: 19.9 t ADT: 26

185TH ST

Poor

Over: VOLGA RIVER

093100205, Fayette, IA

Built 1957 Load: 19.9 t ADT: 15

LOCAL

Poor

Over: PRICE CREEK

081090802, Iowa, IA

Built 1940 Load: 19.9 t ADT: 100

LOCAL

Poor

Over: DRAINAGE

073191301, Monroe, IA

Built 1997 Load: 19.9 t ADT: 45

HWY 927

Poor

Over: ELKHORN CREEK

078010403, Muscatine, IA

Built 1929 Load: 19.9 t ADT: 2,340

LOCAL

Poor

Over: HALFWAY CREEK

089382202, Sac, IA

Built 1918 Load: 19.9 t ADT: 50

LOCAL

Poor

Over: DRAINAGE DITCH 121

093250202, Wright, IA

Built 1900 Load: 19.9 t ADT: 15

210TH STREET

Poor

Over: STREAM

072323301, Adams, IA

Built 1957 Load: 20.0 t ADT: 11

200TH STREET

Poor

Over: STREAM

072331907, Adams, IA

Built 1958 Load: 20.0 t ADT: 15

OSAGE RD

Poor

Over: ELK RUN CREEK

89-12-34-01-10, Black Hawk, IA

Built 1970 Load: 20.0 t ADT: 470

LOCAL - 560TH

Poor

Over: WATERWAY

074371602, Cass, IA

Built 1900 Load: 20.0 t ADT: 15

FM 590TH ST.

Poor

Over: PITCHER CREEK

091393501, Cherokee, IA

Built 1924 Load: 20.0 t ADT: 5

LOCAL-500TH ST

Poor

Over: BR MAPLE RIVER

092391401, Cherokee, IA

Built 1919 Load: 20.0 t ADT: 20

FM

Poor

Over: CEDAR CREEK

095143101, Chickasaw, IA

Built 1960 Load: 20.0 t ADT: 98

FM

Poor

Over: FOX RIVER

068120204, Davis, IA

Built 1955 Load: 20.0 t ADT: 50

FM

Poor

Over: SMALL STREAM

070141004, Davis, IA

Built 1954 Load: 20.0 t ADT: 60

30TH ST.

Poor

Over: GUNDLACH CREEK

091082501, Fayette, IA

Built 1959 Load: 20.0 t ADT: 11

J AVE.

Poor

Over: E BR BUFFALO CR

091083402, Fayette, IA

Built 1962 Load: 20.0 t ADT: 33

FM

Poor

Over: DRAINAGE DITCH

096181401, Floyd, IA

Built 1919 Load: 20.0 t ADT: 1,159

LOCAL

Poor

Over: SMALL CREEK

078332002, Guthrie, IA

Built 1949 Load: 20.0 t ADT: 15

LOCAL

Poor

Over: BEAR CR

086233601, Hamilton, IA

Built 1918 Load: 20.0 t ADT: 15

LOCAL

Poor

Over: DRAINAGE DITCH

089231501, Hamilton, IA

Built 1925 Load: 20.0 t ADT: 5

400TH

Poor

Over: BEAVER CREEK

098160105, Mitchell, IA

Built 1915 Load: 20.0 t ADT: 29

LOCAL

Poor

Over: DRAINAGE DITCH

094313004, Palo Alto, IA

Built 1975 Load: 20.0 t ADT: 26

LYNX AVE

Poor

Over: MUDDY CREEK

090453302, Plymouth, IA

Built 1949 Load: 20.0 t ADT: 34

LOCAL

Poor

Over: SMALL STREAM

083132506, Tama, IA

Built 1987 Load: 20.0 t ADT: 29

LOCAL SO.CHERRY

Poor

Over: SMALL STREAM

072301802, Union, IA

Built 1968 Load: 20.0 t ADT: 278

LOCAL

Poor

Over: SMALL STREAM

073290105, Union, IA

Built 1900 Load: 20.0 t ADT: 5

FM

Poor

Over: DRAINAGE DITCH

090232704, Wright, IA

Built 1970 Load: 20.0 t ADT: 390

LOCAL

Poor

Over: WEYFORD CREEK

098032503, Allamakee, IA

Built 1960 Load: 20.1 t ADT: 29

LOCAL

Poor

Over: BRUSHY FORK CREEK

083350805, Carroll, IA

Built 1974 Load: 20.1 t ADT: 20

FM

Poor

Over: FLINT RIVER

070040106, Des Moines, IA

Built 1941 Load: 20.1 t ADT: 280

LOCAL

Poor

Over: CREEK

086E20903, Jackson, IA

Built 1940 Load: 20.1 t ADT: 40

LOCAL

Poor

Over: SNIPE CREEK

082193502, Marshall, IA

Built 1939 Load: 20.1 t ADT: 21

LOCAL

Poor

Over: MIDDLE TIMBER CREEK

083183202, Marshall, IA

Built 1940 Load: 20.1 t ADT: 41

440TH

Poor

Over: DEER CREEK

099181601, Mitchell, IA

Built 1950 Load: 20.1 t ADT: 59

LOCAL SEC RD

Poor

Over: LITTLE WATERMAN CR

095390401, O'Brien, IA

Built 1919 Load: 20.1 t ADT: 5

240TH STREET

Poor

Over: STREAM

068362103, Page, IA

Built 1974 Load: 20.1 t ADT: 11

FM

Poor

Over: DD

094311101, Palo Alto, IA

Built 1946 Load: 20.1 t ADT: 72

LOCAL

Poor

Over: DD 175

096333403, Palo Alto, IA

Built 1960 Load: 20.1 t ADT: 51

LOCAL

Poor

Over: STREAM

080140703, Poweshiek, IA

Built 1959 Load: 20.1 t ADT: 15

FM

Poor

Over: WOLF CREEK

086121004, Benton, IA

Built 1953 Load: 20.2 t ADT: 30

FM

Poor

Over: IOWAY CREEK

085253501, Boone, IA

Built 1949 Load: 20.2 t ADT: 50

LOCAL

Poor

Over: WILLOW CREEK

083332402, Carroll, IA

Built 1900 Load: 20.2 t ADT: 40

Showing 18,001-18,050 of 20,753 bridges

Related

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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.