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

Structurally Deficient

Over: OVER IMRL RR

072141205, Wapello, IA

Built 1970 ADT: 62

25TH AVE

Structurally Deficient

Over: UNNAMED CREEK

073121104, Wapello, IA

Built 1935 ADT: 11

LOCAL ROAD

Structurally Deficient

Over: BRANCH OTTER CREEK

074232006, Warren, IA

Built 1950 ADT: 15

LOCAL ROAD

Structurally Deficient

Over: MILL BRANCH

074233602, Warren, IA

Built 1920 ADT: 82

LOCAL

Structurally Deficient

Over: BROADHORN CREEK

074250504, Warren, IA

Built 1915 ADT: 46

LOCAL ROAD

Structurally Deficient

Over: BOX ELDER CREEK

074251405, Warren, IA

Built 1940 ADT: 15

LOCAL ROAD

Structurally Deficient

Over: BRANCH COAL CREEK

075220802, Warren, IA

Built 1960 ADT: 26

LOCAL ROAD

Structurally Deficient

Over: FLANK CR

075223303, Warren, IA

Built 1955 ADT: 30

LOCAL ROAD

Structurally Deficient

Over: FLANK CREEK

075223402, Warren, IA

Built 1963 ADT: 26

LOCAL ROAD

Structurally Deficient

Over: BRANCH PAINTER CREEK

075252803, Warren, IA

Built 1961 ADT: 51

FM

Structurally Deficient

Over: BR SOUTH RIVER

076232606, Warren, IA

Built 1954 ADT: 170

FM

Structurally Deficient

Over: WEST FORK LOCUST

067200504, Wayne, IA

Built 1951 ADT: 80

FM

Structurally Deficient

Over: JACKSON CREEK

068210107, Wayne, IA

Built 1953 ADT: 25

LOCAL

Structurally Deficient

Over: STREAM

068222704, Wayne, IA

Built 1968 ADT: 20

LOCAL

Structurally Deficient

Over: JACKSON CREEK

069213302, Wayne, IA

Built 1987 ADT: 26

LOCAL

Structurally Deficient

Over: HUNTER CREEK

069233004, Wayne, IA

Built 1979 ADT: 20

LOCAL

Structurally Deficient

Over: DUCK VALLEY

070211406, Wayne, IA

Built 1968 ADT: 5

FM

Structurally Deficient

Over: BRUSH CREEK

070220109, Wayne, IA

Built 1959 ADT: 50

FM

Structurally Deficient

Over: DRAINAGE

088302004, Webster, IA

Built 1973 ADT: 628

LOCAL

Structurally Deficient

Over: DD

089273402, Webster, IA

Built 1976 ADT: 46

LOCAL

Structurally Deficient

Over: LIZARD CREEK

090303302, Webster, IA

Built 1962 ADT: 15

LOCAL

Structurally Deficient

Over: N FORK BUFFALO CREEK

099262501, Winnebago, IA

Built 1900 ADT: 5

150TH ST

Structurally Deficient

Over: STREAM

096090805, Winneshiek, IA

Built 1892 ADT: 69

LOCAL

Structurally Deficient

Over: WOLF CREEK

086450102 Hancock Ave K67, Woodbury, IA

Built 1950 ADT: 20

LOCAL

Structurally Deficient

Over: GARRETSON DRAINAGE DITCH

086450701, Woodbury, IA

Built 1970 ADT: 20

LOCAL

Structurally Deficient

Over: MILLER CREEK

087433406, Woodbury, IA

Built 1951 ADT: 5

LOCAL

Structurally Deficient

Over: STREAM

087440102, Woodbury, IA

Built 1938 ADT: 15

LOCAL

Structurally Deficient

Over: W FK LITTLE SIOUX RIVER

087450405, Woodbury, IA

Built 1935 ADT: 11

LOCAL

Structurally Deficient

Over: STREAM

088431004, Woodbury, IA

Built 1950 ADT: 15

LOCAL

Structurally Deficient

Over: STREAM

088431401, Woodbury, IA

Built 1950 ADT: 50

LOCAL

Structurally Deficient

Over: CREEK

088431701, Woodbury, IA

Built 1955 ADT: 15

LOCAL

Structurally Deficient

Over: WOLF CREEK

088440902, Woodbury, IA

Built 1940 ADT: 30

LOCAL

Structurally Deficient

Over: BIG WHISKEY CREEK

088460701, Woodbury, IA

Built 1953 ADT: 30

LOCAL

Structurally Deficient

Over: MUDDY CREEK

089451701, Woodbury, IA

Built 1970 ADT: 60

LOCAL

Structurally Deficient

Over: BIG WHISKEY CREEK

089461301, Woodbury, IA

Built 1960 ADT: 50

355TH

Structurally Deficient

Over: STREAM

098212903, Worth, IA

Built 1900 ADT: 11

390TH

Structurally Deficient

Over: STREAM

098221001, Worth, IA

Built 1959 ADT: 41

LOCAL

Structurally Deficient

Over: WHITE FOX CREEK

090251301, Wright, IA

Built 1941 ADT: 11

LOCAL

Structurally Deficient

Over: DRAINAGE DITCH 3

091231604, Wright, IA

Built 1979 ADT: 15

LOCAL

Structurally Deficient

Over: DRAINAGE DITCH 111

092230102, Wright, IA

Built 1900 ADT: 11

FM

Structurally Deficient

Over: SMALL STREAM

092232704, Wright, IA

Built 1954 ADT: 61

LOCAL

Structurally Deficient

Over: DRAINAGE DITCH 36

092252001, Wright, IA

Built 1967 ADT: 26

LOCAL

Structurally Deficient

Over: EAGLE CREEK

092253301, Wright, IA

Built 1975 ADT: 51

LOCAL

Structurally Deficient

Over: IOWA RIVER

093230603, Wright, IA

Built 1975 ADT: 42

BUCHANAN AVE

Structurally Deficient

Over: BOONE RIVER

093262004, Wright, IA

Built 1912 ADT: 35

270TH STREET

Structurally Deficient

Over: ROSE BRANCH

071343401, Adams, IA

Built 1976 Load: 2.7 t ADT: 79

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

Showing 19,801-19,850 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.