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

LOC 200TH ST

Structurally Deficient

Over: DRAINAGE DITCH 25

095271301, Kossuth, IA

Built 1969 Load: 16.1 t ADT: 11

FM

Structurally Deficient

Over: LITTLE SIOUX RIVER

084441803, Monona, IA

Built 1960 Load: 16.1 t ADT: 131

LOCAL

Structurally Deficient

Over: GRAYBILL CREEK

074402403, Pottawattamie, IA

Built 1951 Load: 16.1 t ADT: 26

FM

Structurally Deficient

Over: SMALL STREAM

086370502, Sac, IA

Built 1945 Load: 16.1 t ADT: 26

240 STREET

Structurally Deficient

Over: STREAM

068401901, Fremont, IA

Built 1957 Load: 16.2 t ADT: 15

REDWOOD AVE

Structurally Deficient

Over: BNSF RR

071361804, Montgomery, IA

Built 1913 Load: 16.2 t ADT: 15

LOCAL

Structurally Deficient

Over: STREAM

067300201, Ringgold, IA

Built 1967 Load: 16.2 t ADT: 40

FM

Structurally Deficient

Over: LITTLE RIVER

067251309, Decatur, IA

Built 1959 Load: 16.3 t ADT: 170

LOCAL

Structurally Deficient

Over: SMALL

084203002, Marshall, IA

Built 1983 Load: 16.3 t ADT: 20

LOCAL

Structurally Deficient

Over: DD 21

095320901, Palo Alto, IA

Built 1960 Load: 16.3 t ADT: 21

LOCAL

Structurally Deficient

Over: COAL CREEK

076133601, Keokuk, IA

Built 1948 Load: 16.4 t ADT: 15

LOCAL

Structurally Deficient

Over: WALNUT CREEK

081141702, Poweshiek, IA

Built 1915 Load: 16.4 t ADT: 26

107TH AVE

Structurally Deficient

Over: CREEK

096071306, Winneshiek, IA

Built 1965 Load: 16.4 t ADT: 78

LOCAL

Structurally Deficient

Over: MORGAN CREEK

083093602, Benton, IA

Built 1964 Load: 16.5 t ADT: 90

LOCAL

Structurally Deficient

Over: PLATTE RIVER

071312602, Union, IA

Built 1989 Load: 16.5 t ADT: 11

LOCAL

Structurally Deficient

Over: BR OPOSSUM CK

084090601, Benton, IA

Built 1958 Load: 16.6 t ADT: 20

210TH STREET

Structurally Deficient

Over: DRAINAGE

069433403, Fremont, IA

Built 1966 Load: 16.6 t ADT: 15

FM

Structurally Deficient

Over: BLACKHAWK CREEK ,BRANCH

088162001, Grundy, IA

Built 1956 Load: 16.6 t ADT: 177

LOCAL

Structurally Deficient

Over: DRAINAGE

077263103, Madison, IA

Built 1972 Load: 16.6 t ADT: 50

FM

Structurally Deficient

Over: GREYS CREEK

073172208, Monroe, IA

Built 1965 Load: 16.6 t ADT: 60

180TH ST

Structurally Deficient

Over: SUGAR CREEK

081021603, Cedar, IA

Built 1976 Load: 16.7 t ADT: 45

U AVE

Structurally Deficient

Over: MAPLE CREEK

091390401, Cherokee, IA

Built 1976 Load: 16.7 t ADT: 5

LOCAL

Structurally Deficient

Over: STREAM

070312002, Ringgold, IA

Built 1957 Load: 16.8 t ADT: 11

LOCAL

Structurally Deficient

Over: SMALL STREAM

073283601, Union, IA

Built 1943 Load: 16.8 t ADT: 30

LOCAL

Structurally Deficient

Over: BR MINERVA CR

085200804, Marshall, IA

Built 1917 Load: 16.9 t ADT: 15

LOCAL

Structurally Deficient

Over: SUGAR CREEK

083160506, Tama, IA

Built 1900 Load: 16.9 t ADT: 88

FM

Structurally Deficient

Over: PRAIRIE CREEK

082103001, Benton, IA

Built 1900 Load: 17.0 t ADT: 80

FM

Structurally Deficient

Over: BR LITTLE BEAR CREEK

083101302, Benton, IA

Built 1929 Load: 17.0 t ADT: 422

FM

Structurally Deficient

Over: BROOKS CREEK

091370802, Buena Vista, IA

Built 1966 Load: 17.0 t ADT: 509

LOCAL

Structurally Deficient

Over: CREEK

088023004, Dubuque, IA

Built 1928 Load: 17.0 t ADT: 78

160TH ST

Structurally Deficient

Over: L WAPSIPINICON RIVER

093101903, Fayette, IA

Built 1916 Load: 17.0 t ADT: 43

EAGLE RD.

Structurally Deficient

Over: QUINN CR

095071904, Fayette, IA

Built 1917 Load: 17.0 t ADT: 49

LOCAL

Structurally Deficient

Over: STREAM

078300302, Guthrie, IA

Built 1975 Load: 17.0 t ADT: 20

LOCAL

Structurally Deficient

Over: TRIB. TO TROUBLESOME

079332701, Guthrie, IA

Built 1920 Load: 17.0 t ADT: 60

LOCAL

Structurally Deficient

Over: TRIB. TO TROUBLESOME

079333402, Guthrie, IA

Built 1920 Load: 17.0 t ADT: 20

LOCAL RD

Structurally Deficient

Over: STREAM

081311602, Guthrie, IA

Built 1920 Load: 17.0 t ADT: 15

LOCAL

Structurally Deficient

Over: SOUTH FORK

089223203, Hardin, IA

Built 1919 Load: 17.0 t ADT: 29

S 68TH AVE W

Structurally Deficient

Over: RED ROCK CREEK

079203101, Jasper, IA

Built 1915 Load: 17.0 t ADT: 104

FM

Structurally Deficient

Over: CREEK

082183101, Marshall, IA

Built 1934 Load: 17.0 t ADT: 44

LOCAL RD

Structurally Deficient

Over: INDIAN CREEK

074381701, Pottawattamie, IA

Built 1950 Load: 17.0 t ADT: 29

LOCAL

Structurally Deficient

Over: SMALL STREAM

081160802, Poweshiek, IA

Built 1925 Load: 17.0 t ADT: 20

LOCAL

Structurally Deficient

Over: STREAM

069311801, Ringgold, IA

Built 1948 Load: 17.0 t ADT: 29

ADAMS TAYLOR

Structurally Deficient

Over: TODD BRANCH

070320301, Taylor, IA

Built 1940 Load: 17.0 t ADT: 29

RUSTIN ST

Structurally Deficient

Over: BACON CREEK

000000000, Woodbury, IA

Built 1900 Load: 17.0 t ADT: 188

YORK AVE

Structurally Deficient

Over: PLUNGER CREEK

077303602, Adair, IA

Built 1938 Load: 17.1 t ADT: 35

LOCAL

Structurally Deficient

Over: LONG BRANCH

067160906, Appanoose, IA

Built 1900 Load: 17.1 t ADT: 26

120TH ST

Structurally Deficient

Over: STREAM

093161401, Butler, IA

Built 1981 Load: 17.1 t ADT: 48

FM

Structurally Deficient

Over: DD

088321901, Calhoun, IA

Built 1973 Load: 17.1 t ADT: 30

LOCAL

Structurally Deficient

Over: BRANCH BEE CREEK

071262204, Clarke, IA

Built 1955 Load: 17.1 t ADT: 15

LOCAL

Structurally Deficient

Over: SOUTH RIVER

073271605, Clarke, IA

Built 1979 Load: 17.1 t ADT: 26

Showing 20,451-20,500 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.