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

JUNIPER AVE

Poor

Over: MINK CREEK

093461102, Plymouth, IA

Built 1900 Load: 21.4 t ADT: 45

LOCAL

Poor

Over: SMALL STREAM

078371001, Shelby, IA

Built 1976 Load: 21.4 t ADT: 15

380TH

Poor

Over: STREAM

098201601, Worth, IA

Built 1964 Load: 21.4 t ADT: 33

LOCAL

Poor

Over: CREEK

081350701, Audubon, IA

Built 1951 Load: 21.5 t ADT: 5

FM

Poor

Over: LONG CREEK

069033005, Des Moines, IA

Built 1950 Load: 21.5 t ADT: 60

FM

Poor

Over: LONG DICK CREEK

086230901, Hamilton, IA

Built 1924 Load: 21.5 t ADT: 30

FM LAREDO AVE

Poor

Over: ALLEN CREEK

080431706, Harrison, IA

Built 1942 Load: 21.5 t ADT: 139

LOCAL

Poor

Over: SMALL STREAM

073031704, Louisa, IA

Built 1974 Load: 21.5 t ADT: 51

LOCAL

Poor

Over: DRAINAGE

075282004, Madison, IA

Built 1948 Load: 21.5 t ADT: 26

CO ENTRANCE

Poor

Over: DRAINAGE

00000, Madison, IA

Built 1972 Load: 21.5 t ADT: 11

LOCAL

Poor

Over: SMALL

084172102, Marshall, IA

Built 1979 Load: 21.5 t ADT: 51

LOCAL

Poor

Over: CREEK

085193608, Marshall, IA

Built 1940 Load: 21.5 t ADT: 21

190TH ST

Poor

Over: DRAINAGE

092462301, Plymouth, IA

Built 1949 Load: 21.5 t ADT: 20

LOCAL B LEVEL

Poor

Over: SMALL STREAM

073283103, Union, IA

Built 1973 Load: 21.5 t ADT: 5

OSAGE RD

Poor

Over: POYNER CREEK

89-11-31-01-10, Black Hawk, IA

Built 1960 Load: 21.6 t ADT: 59

FM

Poor

Over: NICHOLSON CREEK

080042002, Cedar, IA

Built 1960 Load: 21.6 t ADT: 820

FM AMANA RD

Poor

Over: BR IOWA RIVER

081082403, Johnson, IA

Built 1935 Load: 21.6 t ADT: 130

FM

Poor

Over: DRAINAGE

075282203, Madison, IA

Built 1975 Load: 21.6 t ADT: 180

FM

Poor

Over: N SKUNK RIVER

083202805, Marshall, IA

Built 1917 Load: 21.6 t ADT: 79

LOCAL

Poor

Over: SUN VALLEY CREEK

070302806, Ringgold, IA

Built 1975 Load: 21.6 t ADT: 34

FIELD ENTRANCE

Poor

Over: SMALL STREAM

078373201, Shelby, IA

Built 1942 Load: 21.6 t ADT: 10

LOCAL-V AVE.

Poor

Over: SMALL CREEK

092390302, Cherokee, IA

Built 1917 Load: 21.7 t ADT: 26

FM 140TH AVE

Poor

Over: SMALL STREAM

088061102, Delaware, IA

Built 1972 Load: 21.7 t ADT: 69

LOCAL

Poor

Over: CREEK

090011303, Dubuque, IA

Built 1940 Load: 21.7 t ADT: 120

A AVE / N58

Poor

Over: RACCOON RIVER

084321802, Greene, IA

Built 1950 Load: 21.7 t ADT: 131

LOCAL ROAD

Poor

Over: CREEK

087151304, Grundy, IA

Built 1977 Load: 21.7 t ADT: 15

MARTIN CR.RD.

Poor

Over: MARTINS CR

083061105, Linn, IA

Built 1972 Load: 21.7 t ADT: 120

HILLS MILL RD

Poor

Over: BUFFALO CREEK

086052912, Linn, IA

Built 1940 Load: 21.7 t ADT: 88

R AVENUE

Poor

Over: STREAM

068371204, Page, IA

Built 1980 Load: 21.7 t ADT: 26

200TH ST

Poor

Over: CLEAR CREEK

092433003, Plymouth, IA

Built 1946 Load: 21.7 t ADT: 5

515TH STREET

Poor

Over: STREAM

077382206, Pottawattamie, IA

Built 1991 Load: 21.7 t ADT: 5

LOCAL

Poor

Over: LONG BRANCH

801637, Shelby, IA

Built 1940 Load: 21.7 t ADT: 51

LOCAL

Poor

Over: SALT CREEK

085143002, Tama, IA

Built 1910 Load: 21.7 t ADT: 15

FIELD ENTRANCE

Poor

Over: STREAM (SDB)

069201906, Wayne, IA

Built 1900 Load: 21.7 t ADT: 10

LOCAL 430TH ST

Poor

Over: CREEK

093401003, Cherokee, IA

Built 1936 Load: 21.8 t ADT: 20

FM

Poor

Over: WINNEBAGO RIVER

096183108, Floyd, IA

Built 1964 Load: 21.8 t ADT: 442

LOCAL ROAD

Poor

Over: MUNNS CREEK

087162102, Grundy, IA

Built 1971 Load: 21.8 t ADT: 29

LOCAL

Poor

Over: STREAM

078300302, Guthrie, IA

Built 1943 Load: 21.8 t ADT: 20

FM

Poor

Over: DRAINAGE DITCH

089231006, Hamilton, IA

Built 1960 Load: 21.8 t ADT: 319

S 112TH AVE W

Poor

Over: PRAIRIE CREEK

078212503, Jasper, IA

Built 1950 Load: 21.8 t ADT: 47

LOCAL

Poor

Over: SMALL STREAM

081171701, Jasper, IA

Built 1948 Load: 21.8 t ADT: 11

LOCAL

Poor

Over: LINN CR

084193002, Marshall, IA

Built 1945 Load: 21.8 t ADT: 44

LOCAL

Poor

Over: LITTLE ASHER CR

085181504, Marshall, IA

Built 1984 Load: 21.8 t ADT: 39

LOCAL

Poor

Over: DRAINAGE

074380401, Pottawattamie, IA

Built 1995 Load: 21.8 t ADT: 11

LOCAL

Poor

Over: PIGEON CREEK

803140, Shelby, IA

Built 1947 Load: 21.8 t

FM

Poor

Over: HOG BRANCH

069320804, Taylor, IA

Built 1975 Load: 21.8 t ADT: 390

FM

Poor

Over: N. FORK LONG CREEK

076073304, Washington, IA

Built 1961 Load: 21.8 t ADT: 440

LOCAL - AKRON

Poor

Over: SMALL STREAM

077340401, Cass, IA

Built 1987 Load: 21.9 t ADT: 11

130TH ST

Poor

Over: MILL CR

082022201, Cedar, IA

Built 1930 Load: 21.9 t ADT: 20

160TH ST

Poor

Over: UNAMED CREEK

093092301, Fayette, IA

Built 1970 Load: 21.9 t ADT: 33

Showing 18,201-18,250 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.