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

Fair

Over: BLACK HAWK CREEK

088160102, Grundy, IA

Built 1991 Load: 32.7 t ADT: 33

LOCAL

Fair

Over: BRANCH BLACKHAWK CREEK

088171102, Grundy, IA

Built 1988 Load: 32.7 t ADT: 33

205TH ST

Fair

Over: BLACKHAWK CREEK

088172703, Grundy, IA

Built 1993 Load: 32.7 t ADT: 452

FM

Fair

Over: BRANCH BLACKHAWK CREEK

088172704, Grundy, IA

Built 1988 Load: 32.7 t ADT: 34

LOCAL

Fair

Over: BRANCH BEAVER CREEK

088180904, Grundy, IA

Built 1988 Load: 32.7 t ADT: 70

LOCAL

Fair

Over: FORK OF BEAVER CREEK

088181502, Grundy, IA

Built 1984 Load: 32.7 t ADT: 44

FM

Fair

Over: BRANCH OF IOWA RIVER

088183102, Grundy, IA

Built 1987 Load: 32.7 t ADT: 79

LOCAL

Fair

Over: BRANCH BLACKHAWK CREEK

089153201, Grundy, IA

Built 1988 Load: 32.7 t ADT: 49

FM

Fair

Over: BEAVER CREEK ,BRANCH

089172702, Grundy, IA

Built 1970 Load: 32.7 t ADT: 69

FM

Fair

Over: BEAVER CREEK ,NORTH FORK

089181302, Grundy, IA

Built 1989 Load: 32.7 t ADT: 452

FM

Fair

Over: BEAVER CREEK ,NORTH FORK

089182401, Grundy, IA

Built 1990 Load: 32.7 t ADT: 373

LOCAL

Fair

Over: STREAM

080332601, Guthrie, IA

Built 1988 Load: 32.7 t ADT: 34

LOCAL

Fair

Over: TROUBLESOME CREEK

079332001, Guthrie, IA

Built 1990 Load: 32.7 t ADT: 15

KANTOR AVE

Fair

Over: LYONS CREEK

089253406, Hamilton, IA

Built 2003 Load: 32.7 t ADT: 270

FM 1440 110TH

Fair

Over: WEST BRANCH IA RIVER

094243301, Hancock, IA

Built 1976 Load: 32.7 t ADT: 429

FM 3170 VALLEY

Fair

Over: WINNEBAGO RIVER

097231606, Hancock, IA

Built 1974 Load: 32.7 t ADT: 190

IA 175

Fair

Over: BEAVER CREEK

0.6 MILE W OF JCT SR D41, Hardin, IA

Built 1990 Load: 32.7 t ADT: 2,210

L20 LOESS HILLS

Fair

Over: SMALL NATURAL STREAM

078440306, Harrison, IA

Built 1926 Load: 32.7 t ADT: 1,534

288TH STREET

Fair

Over: PATATO CREEK

078420409, Harrison, IA

Built 1995 Load: 32.7 t ADT: 15

330TH ST

Fair

Over: POTATO CREEK

078423003, Harrison, IA

Built 1980 Load: 32.7 t ADT: 29

FM & 296TH ST

Fair

Over: HARRIS GROVE CREEK

078431105, Harrison, IA

Built 1900 Load: 32.7 t ADT: 379

LOC MUNICE AVE

Fair

Over: SMALL CREEK

078442408, Harrison, IA

Built 1956 Load: 32.7 t ADT: 240

REDWOOD AVE

Fair

Over: SIX MILE CREEK

079421108, Harrison, IA

Built 1992 Load: 32.7 t ADT: 45

242 TRAIL

Fair

Over: HOG CREEK

079431405, Harrison, IA

Built 1900 Load: 32.7 t ADT: 71

260TH ST

Fair

Over: HOG CREEK

079432205, Harrison, IA

Built 1950 Load: 32.7 t ADT: 417

220TH ST

Fair

Over: SPOONER DITCH

079440501, Harrison, IA

Built 1970 Load: 32.7 t ADT: 11

235TH ST

Fair

Over: SPOONER DITCH

079440703, Harrison, IA

Built 1962 Load: 32.7 t ADT: 15

AUSTIN AVE

Fair

Over: OLD SOLDIER DITCH

079441802, Harrison, IA

Built 1984 Load: 32.7 t ADT: 558

LOC 180TH ST

Fair

Over: S PICAYUNE CREEK

000000000, Harrison, IA

Built 2009 Load: 32.7 t ADT: 29

FM & 194TH ST

Fair

Over: S PICAYUNE CREEK

080412005, Harrison, IA

Built 1979 Load: 32.7 t ADT: 518

210TH TRAIL

Fair

Over: SPOONER DITCH

080443104, Harrison, IA

Built 1959 Load: 32.7 t ADT: 29

FM & QUAY AVE

Fair

Over: SMALL STREAM

081423406, Harrison, IA

Built 1948 Load: 32.7 t ADT: 40

FM & RACINE TRL

Fair

Over: SMALL CREEK

081423603, Harrison, IA

Built 1947 Load: 32.7 t ADT: 71

FM 110TH ST

Fair

Over: STRAW CREEK

081431001, Harrison, IA

Built 1900 Load: 32.7 t ADT: 26

193RD LANE

Fair

Over: STEER CREEK

080442203, Harrison, IA

Built 1971 Load: 32.7 t ADT: 10

WALDORF AVENUE

Fair

Over: CREEK

078411604, Harrison, IA

Built 1950 Load: 32.7 t ADT: 60

KENDRICK AVE

Fair

Over: ALLEN CREEK

000000000, Harrison, IA

Built 2010 Load: 32.7 t ADT: 29

LOCAL

Fair

Over: BRUSH CREEK

070050706, Henry, IA

Built 1984 Load: 32.7 t ADT: 73

FM

Fair

Over: BOUGUS CREEK

070062209, Henry, IA

Built 1985 Load: 32.7 t ADT: 450

FM

Fair

Over: SPEARMAN BRANCH

071062604, Henry, IA

Built 1979 Load: 32.7 t ADT: 260

LOCAL

Fair

Over: SPEARMAN BRANCH

071062606, Henry, IA

Built 1977 Load: 32.7 t ADT: 82

FM

Fair

Over: BERRY BR

071072902, Henry, IA

Built 1977 Load: 32.7 t ADT: 60

FM

Fair

Over: SMALL STREAM

071073202, Henry, IA

Built 1974 Load: 32.7 t ADT: 50

FM

Fair

Over: STREAM

072053102, Henry, IA

Built 1984 Load: 32.7 t ADT: 130

FM

Fair

Over: BRANCH 0F MUD CREEK

072071311, Henry, IA

Built 1985 Load: 32.7 t ADT: 780

LOCAL

Fair

Over: EAST FORK CROOKED CREEK

073051202, Henry, IA

Built 1984 Load: 32.7 t ADT: 11

LOCAL

Fair

Over: BR.BRUSH CREEK

071053206, Henry, IA

Built 1993 Load: 32.7 t ADT: 51

185TH ST

Fair

Over: SMALL STREAM

097130303, Howard, IA

Built 1992 Load: 32.7 t ADT: 412

200TH ST

Fair

Over: ELK CREEK

097131701, Howard, IA

Built 1976 Load: 32.7 t ADT: 45

FM 150TH ST

Fair

Over: TURKEY RIVER

98112301, Howard, IA

Built 2009 Load: 32.7 t ADT: 766

Showing 6,601-6,650 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.