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

LOCAL ROAD

Poor

Over: BOHEMIAN CREEK

097101102, Winneshiek, IA

Built 1922 Load: 24.3 t ADT: 88

FM

Poor

Over: DRAINAGE DITCH

087461901, Woodbury, IA

Built 1960 Load: 24.3 t ADT: 369

LOCAL

Poor

Over: STREAM

085331703, Carroll, IA

Built 1970 Load: 24.4 t ADT: 120

VINE ST

Poor

Over: ROCK FALLS CREEK

097190302, Cerro Gordo, IA

Built 1966 Load: 24.4 t ADT: 324

LOCAL

Poor

Over: LAMALEES CREEK

066053506, Lee, IA

Built 1957 Load: 24.4 t ADT: 150

E AVE NORTHWEST

Poor

Over: CEDAR RIVER

000000000, Linn, IA

Built 1979 Load: 24.4 t ADT: 3,447

LOCAL ROAD

Poor

Over: KLONDIKE CREEK

099480104, Lyon, IA

Built 1900 Load: 24.4 t ADT: 41

LOCAL

Poor

Over: DRAINAGE

077261103, Madison, IA

Built 1967 Load: 24.4 t ADT: 11

LOCAL

Poor

Over: SMALL STREAM

086361502, Sac, IA

Built 1985 Load: 24.4 t ADT: 30

LOCAL

Poor

Over: DEER CREEK

090292203, Webster, IA

Built 1925 Load: 24.4 t ADT: 45

FM

Poor

Over: STREAM-D.D.196

086301204, Webster, IA

Built 1900 Load: 24.4 t ADT: 748

240TH STREET

Poor

Over: SAYLINGS CREEK

071321801, Adams, IA

Built 1978 Load: 24.5 t ADT: 26

LOCAL

Poor

Over: CREEK

080352001, Audubon, IA

Built 1934 Load: 24.5 t ADT: 216

LOCAL - NSHNA V

Poor

Over: SMALL STREAM

075370903, Cass, IA

Built 1986 Load: 24.5 t ADT: 62

LOCAL - 560TH

Poor

Over: CREEK

075372802, Cass, IA

Built 1983 Load: 24.5 t ADT: 269

LOCAL - 665TH

Poor

Over: CREEK

076351804, Cass, IA

Built 1983 Load: 24.5 t ADT: 51

LOCAL - 635TH

Poor

Over: TROUBLESOME CREEK

076360301, Cass, IA

Built 1979 Load: 24.5 t ADT: 30

LOCAL- S AVE

Poor

Over: CREEK

090391902, Cherokee, IA

Built 1916 Load: 24.5 t ADT: 15

FM

Poor

Over: EAST WAPSIPINICON RIVER

096132501, Chickasaw, IA

Built 1981 Load: 24.5 t ADT: 59

LOCAL

Poor

Over: BEAR CREEK

078283205, Dallas, IA

Built 1949 Load: 24.5 t ADT: 180

LOCAL

Poor

Over: SMALL STREAM

069040805, Des Moines, IA

Built 1970 Load: 24.5 t ADT: 26

FM

Poor

Over: PAUL CREEK

072020703, Des Moines, IA

Built 1957 Load: 24.5 t ADT: 130

MAIN STREET SOUTH

Poor

Over: SMALL CREEK

069020406, Des Moines, IA

Built 1886 Load: 24.5 t ADT: 3,705

FM 115TH ST

Poor

Over: SMALL STREAM

091191303, Franklin, IA

Built 1965 Load: 24.5 t ADT: 59

LOCAL

Poor

Over: DEER CREEK

078301507, Guthrie, IA

Built 1985 Load: 24.5 t ADT: 20

LOCAL

Poor

Over: BEAVER CREEK

088200602, Hardin, IA

Built 1987 Load: 24.5 t ADT: 51

FM

Poor

Over: SUGAR CREEK

073071402, Henry, IA

Built 1960 Load: 24.5 t ADT: 640

FM

Poor

Over: CREEK

086413601, Ida, IA

Built 1971 Load: 24.5 t ADT: 350

FM

Poor

Over: UNNAMED CREEK

088391302, Ida, IA

Built 1900 Load: 24.5 t ADT: 369

LOCAL

Poor

Over: LITTLE BEAR CREEK

080111704, Iowa, IA

Built 1978 Load: 24.5 t ADT: 40

LOCAL

Poor

Over: SMALL STREAM

073032901, Louisa, IA

Built 1950 Load: 24.5 t ADT: 11

FM

Poor

Over: SMALL STREAM

099463002, Lyon, IA

Built 1972 Load: 24.5 t ADT: 240

LOCAL

Poor

Over: MUD CREEK

085201403, Marshall, IA

Built 1985 Load: 24.5 t ADT: 26

LOCAL

Poor

Over: MCCANDLESS CLEGHORN

084461401, Monona, IA

Built 1976 Load: 24.5 t ADT: 26

LOCAL

Poor

Over: STREAM

085420404, Monona, IA

Built 1973 Load: 24.5 t ADT: 80

FM

Poor

Over: WALNUT CREEK TRIB

071392104, Montgomery, IA

Built 1965 Load: 24.5 t ADT: 153

US 6

Poor

Over: E BR WAPSINONOC CREEK

0.5 mi. E of jct. IA 70, Muscatine, IA

Built 1920 Load: 24.5 t ADT: 1,740

POLK AVE

Poor

Over: DEEP CREEK

092440202, Plymouth, IA

Built 1958 Load: 24.5 t ADT: 60

LOCAL

Poor

Over: STREAM

081150701, Poweshiek, IA

Built 1977 Load: 24.5 t ADT: 30

FM

Poor

Over: OVERFLOW ON BOYER RIVER

089372201, Sac, IA

Built 1964 Load: 24.5 t ADT: 249

NORTH MAIN ST

Poor

Over: SMALL STREAM

083162107, Tama, IA

Built 1962 Load: 24.5 t ADT: 869

FM

Poor

Over: PLAQUE MINE CREEK

082130504, Tama, IA

Built 1970 Load: 24.5 t ADT: 481

LOCAL

Poor

Over: EAST BRANCH SALT CREEK

084131302, Tama, IA

Built 1940 Load: 24.5 t ADT: 35

LOCAL

Poor

Over: WOLF CREEK

085140906, Tama, IA

Built 1975 Load: 24.5 t ADT: 15

LOCAL

Poor

Over: FOUR MILE CREEK

086153002, Tama, IA

Built 1988 Load: 24.5 t ADT: 11

FM

Poor

Over: PLATTE BRANCH

068321201, Taylor, IA

Built 1950 Load: 24.5 t ADT: 45

FM

Poor

Over: WILLIAMS CREEK

074073404, Washington, IA

Built 1936 Load: 24.5 t ADT: 1,650

LOCAL

Poor

Over: GOOSE CREEK

076062401, Washington, IA

Built 1975 Load: 24.5 t ADT: 26

FM

Poor

Over: TROUT RIVER

098072109, Winneshiek, IA

Built 1956 Load: 24.5 t ADT: 953

FM

Poor

Over: CREEK

0884232, Woodbury, IA

Built 1962 Load: 24.5 t ADT: 219

Showing 18,501-18,550 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.