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 - 660TH

Poor

Over: LONE TREE CREEK

075350602, Cass, IA

Built 1900 Load: 17.1 t ADT: 29

LOCAL - 680TH

Poor

Over: SEVEN MILE CREEK

075352102, Cass, IA

Built 1979 Load: 17.1 t ADT: 15

LOCAL/BUCK CRK

Poor

Over: WATERWAY

077362002, Cass, IA

Built 1967 Load: 17.1 t ADT: 41

HICKORY AVE

Poor

Over: CALMUS CREEK

097212004, Cerro Gordo, IA

Built 1917 Load: 17.1 t ADT: 44

M25 Y AVE

Poor

Over: PITCHER CREEK

091392502, Cherokee, IA

Built 1921 Load: 17.1 t ADT: 20

LOCAL 470TH ST

Poor

Over: CREEK

093413401, Cherokee, IA

Built 1924 Load: 17.1 t ADT: 40

FM

Poor

Over: STREAM

096122801, Chickasaw, IA

Built 1981 Load: 17.1 t ADT: 49

LOCAL

Poor

Over: CREEK

069130404, Davis, IA

Built 1940 Load: 17.1 t ADT: 34

FM

Poor

Over: GRAND RIVER

067261305, Decatur, IA

Built 1959 Load: 17.1 t ADT: 329

FM

Poor

Over: POT HOLE CREEK

068271302, Decatur, IA

Built 1957 Load: 17.1 t ADT: 60

LOCAL

Poor

Over: WELDON RIVER

069243303, Decatur, IA

Built 1991 Load: 17.1 t ADT: 5

FM

Poor

Over: WELDON RIVER

070242101, Decatur, IA

Built 1951 Load: 17.1 t ADT: 79

LOCAL

Poor

Over: TRIB. TO TROUBLESOME

079331801, Guthrie, IA

Built 1970 Load: 17.1 t ADT: 11

1760 180TH ST

Poor

Over: EAST IOWA RIVER

095242601, Hancock, IA

Built 1959 Load: 17.1 t ADT: 15

FM

Poor

Over: SUGAR CREEK

073072803, Henry, IA

Built 1959 Load: 17.1 t ADT: 100

FM

Poor

Over: ODEBOLT CREEK

087392204, Ida, IA

Built 1949 Load: 17.1 t ADT: 60

FM

Poor

Over: CREEK

072112202, Jefferson, IA

Built 1949 Load: 17.1 t ADT: 35

LOCAL

Poor

Over: CEDAR CREEK

076133604, Keokuk, IA

Built 1979 Load: 17.1 t ADT: 5

LOC 230TH AVE

Poor

Over: PRAIRIE CREEK

095272602, Kossuth, IA

Built 1986 Load: 17.1 t ADT: 5

FM

Poor

Over: SUGAR CREEK

068071301, Lee, IA

Built 1949 Load: 17.1 t ADT: 30

FM

Poor

Over: STREAM

074182807, Marion, IA

Built 1981 Load: 17.1 t ADT: 120

LOCAL

Poor

Over: BURNETT CR

084170701, Marshall, IA

Built 1957 Load: 17.1 t ADT: 20

320TH

Poor

Over: LITTLE CEDAR RIVER

097161303, Mitchell, IA

Built 1931 Load: 17.1 t ADT: 226

FM

Poor

Over: JORDAN CREEK

082430511, Monona, IA

Built 1958 Load: 17.1 t ADT: 159

FM

Poor

Over: BEAVER CREEK

083430403, Monona, IA

Built 1958 Load: 17.1 t ADT: 11

LOCAL

Poor

Over: MONONA HARRISON DD

084451301, Monona, IA

Built 1959 Load: 17.1 t ADT: 45

FM

Poor

Over: SIOUX RIVER

084452511, Monona, IA

Built 1960 Load: 17.1 t ADT: 45

LOCAL

Poor

Over: WEST FORK DD

085450903, Monona, IA

Built 1961 Load: 17.1 t ADT: 45

FM

Poor

Over: HAITZ DD

085452501, Monona, IA

Built 1961 Load: 17.1 t ADT: 229

LOCAL

Poor

Over: CREEK

078E12102, Muscatine, IA

Built 1960 Load: 17.1 t ADT: 50

FM

Poor

Over: OCHEYEDAN RIVER

099403501, Osceola, IA

Built 1951 Load: 17.1 t ADT: 131

M-32 / C AVE

Poor

Over: STREAM

067390902, Page, IA

Built 1952 Load: 17.1 t ADT: 71

F AVENUE

Poor

Over: WEST TARKIO CREEK

069383002, Page, IA

Built 1977 Load: 17.1 t ADT: 20

J AVENUE

Poor

Over: WEST TARKIO RIVER

070382205, Page, IA

Built 1960 Load: 17.1 t ADT: 60

LOCAL

Poor

Over: STREAM

096310701, Palo Alto, IA

Built 1965 Load: 17.1 t ADT: 26

SHAMROCK AVE

Poor

Over: DEEP CREEK

093431502, Plymouth, IA

Built 1953 Load: 17.1 t ADT: 50

LOCAL

Poor

Over: STREAM

080130501, Poweshiek, IA

Built 1954 Load: 17.1 t ADT: 30

LOCAL

Poor

Over: BIG BEAR CREEK

080141412, Poweshiek, IA

Built 1951 Load: 17.1 t ADT: 161

FM

Poor

Over: SMALL STREAM

086363101, Sac, IA

Built 1974 Load: 17.1 t ADT: 20

FM

Poor

Over: RICHLAND CREEK

082142202, Tama, IA

Built 1946 Load: 17.1 t ADT: 25

FM

Poor

Over: BRANCH IOWA RIVER

084162306, Tama, IA

Built 1965 Load: 17.1 t ADT: 678

LOCAL

Poor

Over: DAUGHERTY CREEK

067340903, Taylor, IA

Built 1952 Load: 17.1 t ADT: 29

FM

Poor

Over: WOLF CREEK

087443003, Woodbury, IA

Built 1958 Load: 17.1 t ADT: 330

DOGWOOD

Poor

Over: STREAM

098220302, Worth, IA

Built 1959 Load: 17.1 t ADT: 236

UNION AVENUE

Poor

Over: STREAM

071322702, Adams, IA

Built 1972 Load: 17.2 t ADT: 15

ELM AVENUE

Poor

Over: WILLIAMS CREEK

073351202, Adams, IA

Built 1968 Load: 17.2 t ADT: 5

FM

Poor

Over: WEST CREEK

073263202, Clarke, IA

Built 1966 Load: 17.2 t ADT: 34

LOCAL

Poor

Over: SEVEN MILE CREEK

067272611, Decatur, IA

Built 1980 Load: 17.2 t ADT: 82

LOCAL

Poor

Over: KILGORE CREEK

068251503, Decatur, IA

Built 1979 Load: 17.2 t ADT: 46

300TH ST

Poor

Over: SMALL STREAM

087051805, Delaware, IA

Built 1930 Load: 17.2 t ADT: 59

Showing 17,601-17,650 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.