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

HICKORY AVE

Good

Over: CEDAR RIVER

098170806, Mitchell, IA

Built 1959 Load: 19.3 t ADT: 403

FM

Good

Over: TROUT RUN CREEK BRANCH

097081009, Winneshiek, IA

Built 1943 Load: 19.3 t ADT: 108

FM

Good

Over: BIG CREEK

084392204, Crawford, IA

Built 1976 Load: 19.4 t ADT: 71

BEECHNUT RD

Good

Over: DIBBLE CR

000000000, Fayette, IA

Built 2009 Load: 19.4 t ADT: 59

LOCAL

Good

Over: SOUTH BRANCH SALT CREEK

084133102, Tama, IA

Built 1945 Load: 19.4 t ADT: 29

FM

Good

Over: UPPER IOWA RIVER

098070709, Winneshiek, IA

Built 2005 Load: 19.4 t ADT: 471

KIMBALL AVE

Good

Over: TRIB TO MILLER CREEK

88-13-34-02-10, Black Hawk, IA

Built 1971 Load: 19.5 t ADT: 432

US 218

Good

Over: DRAINAGE

0.8 mi. N of SR G-62, Washington, IA

Built 1997 Load: 19.5 t ADT: 13,800

315TH AVE

Good

Over: CREEK

0.2 MI N of 210 St, Winneshiek, IA

Built 2019 Load: 19.6 t ADT: 20

220TH ST

Good

Over: FIELD STREAM

083360101, Carroll, IA

Built 2000 Load: 19.7 t ADT: 29

LOCAL

Good

Over: CREEK

089451802, Woodbury, IA

Built 2005 Load: 19.7 t ADT: 26

JESUP RD

Good

Over: TRIB TO SPRING CREEK

88-11-14-02-10, Black Hawk, IA

Built 2000 Load: 19.8 t ADT: 393

LOCAL

Good

Over: SPRING CR

088103201, Buchanan, IA

Built 2005 Load: 19.8 t ADT: 26

PK 658(WANATA)

Good

Over: LITTLE SIOUX RIVER

IN WANATA STATE PARK, Clay, IA

Built 1972 Load: 19.8 t ADT: 58

LOCAL

Good

Over: TRIB DESMOINES RIVER

070121203, Davis, IA

Built 2003 Load: 19.8 t ADT: 60

US 71

Good

Over: STREAM

1.1 mi. N of Jct. SR J-64, Page, IA

Built 1972 Load: 19.8 t ADT: 2,170

IA 2

Good

Over: SNAKE CREEK

0.3 mi. E of Jct. SR M-60, Page, IA

Built 1991 Load: 19.8 t ADT: 3,170

LOCAL

Good

Over: STREAM

088462703, Woodbury, IA

Built 2007 Load: 19.9 t ADT: 40

FM

Good

Over: STREAM

067160805, Appanoose, IA

Built 1994 Load: 20.0 t ADT: 5

IA 210

Good

Over: STREAM

IN MADRID, Boone, IA

Built 1989 Load: 20.0 t ADT: 2,880

740TH ST

Good

Over: SEVEN MILE CREEK

076343302, Cass, IA

Built 2015 Load: 20.0 t ADT: 26

FM

Good

Over: OTTER CREEK

085393601, Crawford, IA

Built 1976 Load: 20.0 t ADT: 40

50TH ST.

Good

Over: GUNDLACH CR

091081401, Fayette, IA

Built 1963 Load: 20.0 t ADT: 33

70TH ST

Good

Over: OTTER CR

091100101, Fayette, IA

Built 1963 Load: 20.0 t ADT: 33

SHIMEK ST FOREST

Good

Over: STREAM

Shimek Forest, Lee, IA

Built 1997 Load: 20.0 t

700TH ST

Good

Over: JIM BRANCH OF TURKEY CR

076352602, Cass, IA

Built 2021 Load: 20.1 t ADT: 11

1ST AVE

Good

Over: RALSTON CREEK S. BRANCH

079061300, Johnson, IA

Built 1997 Load: 20.1 t ADT: 14,992

LOCAL

Good

Over: WEST BRANCH MILL CREEK

096412901, O'Brien, IA

Built 1966 Load: 20.1 t ADT: 46

FM

Good

Over: WATERMAN CREEK

097400102, O'Brien, IA

Built 1965 Load: 20.1 t ADT: 309

FM

Good

Over: PLESSIS CREEK

097402402, O'Brien, IA

Built 1964 Load: 20.1 t ADT: 309

LOCAL RD

Good

Over: SMALL

098390802, Osceola, IA

Built 1957 Load: 20.1 t ADT: 21

LOCAL

Good

Over: STREAM

098412601, Osceola, IA

Built 1967 Load: 20.1 t ADT: 26

FM

Good

Over: DRAINAGE

100402302, Osceola, IA

Built 1968 Load: 20.1 t ADT: 459

FM

Good

Over: SNOW CREEK

100421004, Osceola, IA

Built 1971 Load: 20.1 t ADT: 279

FM

Good

Over: DRY RUN

100422902, Osceola, IA

Built 1942 Load: 20.1 t ADT: 100

REDWOOD ROAD

Good

Over: PRAIRIE ROSE SPILLWAY

078380402, Shelby, IA

Built 2023 Load: 20.1 t ADT: 41

FM-F-65

Good

Over: PLEASANT RUN

078353603, Audubon, IA

Built 1974 Load: 20.2 t ADT: 20

LOCAL

Good

Over: WEST NISHNABOTNA RIVER

083362201, Carroll, IA

Built 1963 Load: 20.2 t ADT: 11

LOCAL

Good

Over: TRIB SO WYCACONDAH DITCH

068141406, Davis, IA

Built 2000 Load: 20.2 t ADT: 45

275TH ST

Good

Over: LITTLLE TURKEY RIVER

095102205, Fayette, IA

Built 1974 Load: 20.2 t ADT: 44

FM

Good

Over: W BR 102 RIVER

069341804, Taylor, IA

Built 1975 Load: 20.2 t ADT: 26

LOCAL

Good

Over: FIELD STREAM

085352206, Carroll, IA

Built 1995 Load: 20.3 t ADT: 71

MALLARD

Good

Over: W FORK BEAVER DAM CREEK

094201802, Cerro Gordo, IA

Built 1944 Load: 20.3 t ADT: 21

260TH ST

Good

Over: BRANCH IOWA RIVER

084153001, Tama, IA

Built 2016 Load: 20.3 t ADT: 11

LOCAL RD

Good

Over: MAPLE RIVER

088402501, Ida, IA

Built 2002 Load: 20.4 t ADT: 21

IA 330

Good

Over: ASHER CREEK

2.0 MILES WEST OF JCT 14, Marshall, IA

Built 1957 Load: 20.4 t ADT: 1,490

FM

Good

Over: NORTH TURKEY CREEK

077321402, Adair, IA

Built 1985 Load: 20.5 t ADT: 60

LOCAL

Good

Over: WALNUT CREEK

069191302, Appanoose, IA

Built 2006 Load: 20.5 t ADT: 35

LOCAL

Good

Over: SOAP CREEK

070162702, Appanoose, IA

Built 2001 Load: 20.5 t ADT: 21

LOCAL

Good

Over: SMALL STREAM

070172503, Appanoose, IA

Built 2001 Load: 20.5 t ADT: 47

Showing 9,151-9,200 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.