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 160TH ST

Poor

Over: PRAIRIE CREEK

094270501, Kossuth, IA

Built 1986 Load: 21.9 t ADT: 5

LOC 170TH ST

Poor

Over: DRAINAGE DITCH NO 9

095303601, Kossuth, IA

Built 1977 Load: 21.9 t ADT: 21

FM

Poor

Over: DRAINAGE

077271501, Madison, IA

Built 1960 Load: 21.9 t ADT: 40

LOCAL

Poor

Over: PILOT CREEK

093330102, Pocahontas, IA

Built 1975 Load: 21.9 t ADT: 30

LOCAL

Poor

Over: N LIZARD CREEK

093340101, Pocahontas, IA

Built 1974 Load: 21.9 t ADT: 20

LOCAL

Poor

Over: SMALL STREAM

086373102, Sac, IA

Built 1971 Load: 21.9 t ADT: 26

FM

Poor

Over: SMALL STREAM

077061903, Washington, IA

Built 1925 Load: 21.9 t ADT: 270

LOCAL

Poor

Over: DRAINAGE DITCH

098240301, Winnebago, IA

Built 1928 Load: 21.9 t ADT: 82

D-25

Poor

Over: ELLIOT CREEK

088463110, Woodbury, IA

Built 1957 Load: 21.9 t ADT: 977

EDLORA RD

Poor

Over: TRIB TO BLACK HAWK CREEK

87-14-05-03-10, Black Hawk, IA

Built 1947 Load: 22.0 t ADT: 59

LOCAL PHEASANT

Poor

Over: SMALL STREAM

087041303, Delaware, IA

Built 1973 Load: 22.0 t ADT: 97

LOCAL 215 AVE

Poor

Over: SMALL STREAM

087052504, Delaware, IA

Built 1965 Load: 22.0 t ADT: 11

FM 280 AVE

Poor

Over: SMALL STREAM

090033002, Delaware, IA

Built 1973 Load: 22.0 t ADT: 79

LOCAL

Poor

Over: STREAM

087011804, Dubuque, IA

Built 1981 Load: 22.0 t ADT: 90

LOCAL

Poor

Over: SMALL

081332004, Guthrie, IA

Built 1979 Load: 22.0 t ADT: 26

STONE CITY RD.

Poor

Over: CROW CREEK

084040603, Jones, IA

Built 1975 Load: 22.0 t ADT: 295

LOCAL

Poor

Over: DRAINAGE

076293602, Madison, IA

Built 1960 Load: 22.0 t ADT: 26

LOCAL

Poor

Over: DRAINAGE

077280202, Madison, IA

Built 1955 Load: 22.0 t ADT: 131

LOCAL

Poor

Over: NORTH SKUNK RIVER

082200203, Marshall, IA

Built 1938 Load: 22.0 t ADT: 29

LOCAL

Poor

Over: CREEK

084180609, Marshall, IA

Built 1955 Load: 22.0 t ADT: 148

SUNSET AVE

Poor

Over: DD

091431402, Plymouth, IA

Built 1956 Load: 22.0 t ADT: 20

FM

Poor

Over: BOYER RIVER

089370402, Sac, IA

Built 1956 Load: 22.0 t ADT: 848

LOCAL

Poor

Over: STREAM

070101101, Van Buren, IA

Built 1930 Load: 22.0 t ADT: 21

FRANKLIN AVE

Poor

Over: BOYLAN CREEK

093192404, Franklin, IA

Built 1964 Load: 22.1 t ADT: 11

220TH STREET

Poor

Over: OTTER CREEK

093203001, Franklin, IA

Built 1972 Load: 22.1 t ADT: 21

1200 210TH ST

Poor

Over: WEST IOWA RIVER

095251201, Hancock, IA

Built 1961 Load: 22.1 t ADT: 170

FM 2380 DEER AV

Poor

Over: DRAINAGE DITCH 97

096262702, Hancock, IA

Built 1968 Load: 22.1 t ADT: 447

LOCAL

Poor

Over: CREEK

087200306, Hardin, IA

Built 1972 Load: 22.1 t ADT: 275

FM

Poor

Over: UNNAMED STREAM

089390102, Ida, IA

Built 1961 Load: 22.1 t ADT: 379

FM

Poor

Over: UNNAMED CREEK

089392310, Ida, IA

Built 1961 Load: 22.1 t ADT: 379

LOC 200TH ST

Poor

Over: PRAIRIE CREEK

095271501, Kossuth, IA

Built 1971 Load: 22.1 t ADT: 15

LOCAL

Poor

Over: WILLOW CREEK

082420103, Monona, IA

Built 1978 Load: 22.1 t ADT: 11

LOCAL

Poor

Over: STREAM

085432701, Monona, IA

Built 1900 Load: 22.1 t ADT: 60

L AVENUE

Poor

Over: SNAKE CREEK

069373106, Page, IA

Built 1979 Load: 22.1 t ADT: 60

240TH ST

Poor

Over: PERRY CREEK

091471401, Plymouth, IA

Built 1900 Load: 22.1 t ADT: 5

LOCAL

Poor

Over: SMALL STREAM

085160801, Tama, IA

Built 1986 Load: 22.1 t ADT: 39

LOCAL

Poor

Over: STREAM

086161803, Tama, IA

Built 1975 Load: 22.1 t ADT: 49

LOCAL (LWC)

Poor

Over: BRANCH ROCK CREEK

086123302, Benton, IA

Built 1984 Load: 22.2 t ADT: 5

LOCAL

Poor

Over: TRIB. OF FOX RIVER

069133504, Davis, IA

Built 1985 Load: 22.2 t ADT: 110

LOC 200TH ST

Poor

Over: LOTTS CREEK

095301701, Kossuth, IA

Built 1969 Load: 22.2 t ADT: 177

FM

Poor

Over: FIELD DRAINAGE DITCH

074261601, Madison, IA

Built 1951 Load: 22.2 t ADT: 417

FM

Poor

Over: BUSHY CREEK

067352603, Taylor, IA

Built 1952 Load: 22.2 t ADT: 40

FM

Poor

Over: NORTH BEAR CREEK

100072202, Winneshiek, IA

Built 1900 Load: 22.2 t ADT: 49

FM-110TH STREET

Poor

Over: WILLIAMS CREEK

073351001, Adams, IA

Built 1964 Load: 22.3 t ADT: 20

FM

Poor

Over: STREAM

080261101, Dallas, IA

Built 1970 Load: 22.3 t ADT: 1,544

FM

Poor

Over: WHITE FOX CREEK

089252103, Hamilton, IA

Built 1960 Load: 22.3 t ADT: 330

FM

Poor

Over: CREEK

087203004, Hardin, IA

Built 1960 Load: 22.3 t ADT: 34

LOCAL

Poor

Over: BYERS BRANCH CREEK

081213404, Jasper, IA

Built 1924 Load: 22.3 t ADT: 47

LOC 210TH AVE

Poor

Over: PRAIRIE CREEK

094273302, Kossuth, IA

Built 1979 Load: 22.3 t ADT: 81

LOC 110TH AVE

Poor

Over: E FORK DES MOINES RIVER

098292602, Kossuth, IA

Built 1980 Load: 22.3 t ADT: 30

Showing 18,251-18,300 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.