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

FM

Poor

Over: N WYACONDAH CREEK

068132605, Davis, IA

Built 1940 Load: 18.4 t ADT: 60

150TH ST

Poor

Over: FLOYD RIVER

093453403, Plymouth, IA

Built 1954 Load: 18.4 t ADT: 131

FM

Poor

Over: SMALL CREEK

096102404, Winneshiek, IA

Built 1900 Load: 18.4 t ADT: 79

LOCAL

Poor

Over: DITCH

086450102, Woodbury, IA

Built 1950 Load: 18.4 t ADT: 20

FM

Poor

Over: BOYLAN CREEK

092181001, Butler, IA

Built 1967 Load: 18.5 t ADT: 29

LOCAL

Poor

Over: D.D.

087333102, Calhoun, IA

Built 1957 Load: 18.5 t ADT: 15

HAYES AVE

Poor

Over: BR ROCK RUN CR

081031704, Cedar, IA

Built 1900 Load: 18.5 t ADT: 26

QUINCY AVE

Poor

Over: BR MILL CR

082021104, Cedar, IA

Built 1925 Load: 18.5 t ADT: 50

FM

Poor

Over: SOUTH WEST CREEK

072261004, Clarke, IA

Built 1978 Load: 18.5 t ADT: 89

JASPER RD.

Poor

Over: FROG HOLLOW CR

094083404, Fayette, IA

Built 1958 Load: 18.5 t ADT: 44

FM

Poor

Over: MIDDLE RIVER

078320802, Guthrie, IA

Built 1959 Load: 18.5 t ADT: 50

LOCAL RD

Poor

Over: SMALL

078330202, Guthrie, IA

Built 1978 Load: 18.5 t ADT: 20

260TH TRAIL

Poor

Over: MASON CREEK

079322205, Guthrie, IA

Built 1987 Load: 18.5 t ADT: 45

FM

Poor

Over: N FORK MAQUOKETA RIVER

085E22107, Jackson, IA

Built 1952 Load: 18.5 t ADT: 400

FM

Poor

Over: CLEAR CREEK

081200801, Jasper, IA

Built 1914 Load: 18.5 t ADT: 40

FM

Poor

Over: DRAINAGE

072080203, Jefferson, IA

Built 1954 Load: 18.5 t ADT: 60

FM

Poor

Over: WEST BRANCH

074293402, Madison, IA

Built 1957 Load: 18.5 t ADT: 131

FM

Poor

Over: BADGER CREEK

077261504, Madison, IA

Built 1956 Load: 18.5 t ADT: 1,404

FM

Poor

Over: TOM CREEK

077283004, Madison, IA

Built 1954 Load: 18.5 t ADT: 477

LOCAL

Poor

Over: CREEK

085182704, Marshall, IA

Built 1918 Load: 18.5 t ADT: 47

FIELD ENTRANCE

Poor

Over: DRAINAGE (SDB)

070391402, Page, IA

Built 1900 Load: 18.5 t ADT: 10

250TH STREET

Poor

Over: STREAM

074421704, Pottawattamie, IA

Built 1940 Load: 18.5 t ADT: 11

LOCAL

Poor

Over: RICHLAND CREEK

082152104, Tama, IA

Built 1925 Load: 18.5 t ADT: 26

LOCAL

Poor

Over: STREAM

071303603, Union, IA

Built 2000 Load: 18.5 t ADT: 15

LOCAL RD

Poor

Over: BR MUD CK

082100203, Benton, IA

Built 1900 Load: 18.6 t ADT: 20

LOCAL

Poor

Over: S CHEQUEST LAKE CREEK

069121504, Davis, IA

Built 1953 Load: 18.6 t ADT: 45

240 TH

Poor

Over: BUTTRICKS CREEK

083301403, Greene, IA

Built 1957 Load: 18.6 t ADT: 26

S 52ND AVE E

Poor

Over: SLATER CREEK

079182401, Jasper, IA

Built 1999 Load: 18.6 t ADT: 62

IRIS AVE

Poor

Over: MINK CREEK

093462102, Plymouth, IA

Built 1900 Load: 18.6 t ADT: 34

270TH ST

Poor

Over: DRAINAGE DITCH

097350201, Dickinson, IA

Built 1926 Load: 18.7 t ADT: 5

LOC 120TH ST

Poor

Over: TRULNER CREEK

094302903, Kossuth, IA

Built 1979 Load: 18.7 t ADT: 21

FM 150TH AVE

Poor

Over: LINDNER CREEK

096280902, Kossuth, IA

Built 1969 Load: 18.7 t ADT: 376

FM

Poor

Over: PITMAN CREEK

068050309, Lee, IA

Built 1975 Load: 18.7 t ADT: 120

FM

Poor

Over: SMALL STREAM

074052801, Louisa, IA

Built 1960 Load: 18.7 t ADT: 660

LOCAL

Poor

Over: OTTER CREEK

099413102, Osceola, IA

Built 1949 Load: 18.7 t ADT: 30

LOCAL

Poor

Over: SUGAR CREEK

079163103, Poweshiek, IA

Built 1958 Load: 18.7 t ADT: 34

LOCAL

Poor

Over: DAUGHERTY CREEK

068343303, Taylor, IA

Built 1977 Load: 18.7 t ADT: 15

LOCAL

Poor

Over: CREEK

068092903, Van Buren, IA

Built 1967 Load: 18.7 t ADT: 11

LOCAL

Poor

Over: COOPER CREEK

068180902, Appanoose, IA

Built 1956 Load: 18.8 t ADT: 104

LOCAL

Poor

Over: D.D.

087340803, Calhoun, IA

Built 1900 Load: 18.8 t ADT: 20

LOCAL

Poor

Over: BROWN CR

100330803, Emmet, IA

Built 1961 Load: 18.8 t ADT: 60

300 TH

Poor

Over: GREENBRIER CREEK

082311401, Greene, IA

Built 1957 Load: 18.8 t ADT: 15

290 TH / E57

Poor

Over: WILLOW CREEK

082320703, Greene, IA

Built 1953 Load: 18.8 t ADT: 89

320 TH

Poor

Over: STREAM

082322801, Greene, IA

Built 1956 Load: 18.8 t ADT: 11

140 TH

Poor

Over: STREAM

085302701, Greene, IA

Built 1956 Load: 18.8 t ADT: 26

LOCAL

Poor

Over: STREAM

080313303, Guthrie, IA

Built 1973 Load: 18.8 t ADT: 50

120TH ST

Poor

Over: STREAM

081050901, Johnson, IA

Built 1952 Load: 18.8 t ADT: 30

160TH ST

Poor

Over: BR MILL CR

081052201, Johnson, IA

Built 1955 Load: 18.8 t ADT: 60

FM

Poor

Over: LITTLE SIOUX RIVER

085440205, Monona, IA

Built 1925 Load: 18.8 t ADT: 159

LOCAL

Poor

Over: WAPSINONOC CREEK

078030703, Muscatine, IA

Built 1936 Load: 18.8 t ADT: 176

Showing 17,851-17,900 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.