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

VINE

Fair

Over: COLD WATER CREEK

094192202, Cerro Gordo, IA

Built 1972 Load: 33.2 t ADT: 16

130TH

Fair

Over: W BR BEAVER DAM CREEK

094222101, Cerro Gordo, IA

Built 1979 Load: 33.2 t ADT: 10

170TH

Fair

Over: BEAVER DAM CREEK

095213501, Cerro Gordo, IA

Built 1981 Load: 33.2 t ADT: 59

LARK

Fair

Over: BEAVER DAM CREEK

095213602, Cerro Gordo, IA

Built 1973 Load: 33.2 t ADT: 589

MALLARD

Fair

Over: CALMUS CREEK

097203004, Cerro Gordo, IA

Built 1964 Load: 33.2 t ADT: 3,290

300TH

Fair

Over: CALMUS CREEK

097212801, Cerro Gordo, IA

Built 1968 Load: 33.2 t ADT: 2,701

FM- L AVE

Fair

Over: BRANCH LITTLE SIOUX RVR

090411302, Cherokee, IA

Built 1971 Load: 33.2 t ADT: 290

290TH ST

Fair

Over: STONEY CREEK

097381401, Clay, IA

Built 2004 Load: 33.2 t ADT: 15

LOCAL

Fair

Over: SMALL

080300303, Guthrie, IA

Built 1978 Load: 33.2 t ADT: 45

IA 2

Fair

Over: DEVIL CREEK

0.5 MI. W OF JCT. US 61, Lee, IA

Built 1973 Load: 33.2 t ADT: 4,250

IA 3

Fair

Over: FLOYD RIVER

1.0 mi. E of US 75, Plymouth, IA

Built 1981 Load: 33.2 t ADT: 4,270

I 880 WB

Fair

Over: BNSF RR

0.3 MI. E OF JCT. 191, Pottawattamie, IA

Built 1966 Load: 33.2 t ADT: 2,850

R38/500TH AVE

Fair

Over: IOWAY CREEK

084240702, Story, IA

Built 1976 Load: 33.2 t ADT: 1,496

500TH

Fair

Over: DEER CREEK

100191801, Worth, IA

Built 1974 Load: 33.2 t ADT: 30

THRUSH

Fair

Over: DRAINAGE DITCH

100192902, Worth, IA

Built 1971 Load: 33.2 t ADT: 393

IA 5

Fair

Over: DME RR

1.0 MI. S OF JCT. SR J18, Appanoose, IA

Built 1974 Load: 33.3 t ADT: 3,120

E AIRLINE HWY

Fair

Over: TRIB TO ELK RUN CREEK

89-11-07-01-10, Black Hawk, IA

Built 1986 Load: 33.3 t ADT: 59

FM- 650TH ST

Fair

Over: STRATTON

090413301, Cherokee, IA

Built 1967 Load: 33.3 t ADT: 180

EAGLE RD

Fair

Over: ROBERTS CREEK

094051604, Clayton, IA

Built 1986 Load: 33.3 t ADT: 98

MILL CR. EXPWY.

Fair

Over: HARTS MILL CREEK

081061505, Clinton, IA

Built 2000 Load: 33.3 t ADT: 8,400

IA 141

Fair

Over: NORTH RACCOON RIVER

1.5 mi. W of IA 144, Dallas, IA

Built 1976 Load: 33.3 t ADT: 3,570

LOCAL

Fair

Over: CURRAN BRANCH

087010104, Dubuque, IA

Built 1938 Load: 33.3 t ADT: 40

W AVE

Fair

Over: STOE CREEK

092101602, Fayette, IA

Built 1963 Load: 33.3 t ADT: 766

IA 2

Fair

Over: EAST NISHNABOTNA RIVER

3.3 MI. W OF JCT. 59, Fremont, IA

Built 1975 Load: 33.3 t ADT: 1,910

FM

Fair

Over: S. RACCOON RIVER

078301003, Guthrie, IA

Built 1959 Load: 33.3 t ADT: 34

LOCAL

Fair

Over: SOUTH RACCOON RIVER

080330304, Guthrie, IA

Built 1986 Load: 33.3 t ADT: 34

LOCAL

Fair

Over: SOUTH RACCOON RIVER

080330403, Guthrie, IA

Built 1986 Load: 33.3 t ADT: 34

US 169

Fair

Over: TRULNER CREEK

0.3 mi. S of SR C20, Humboldt, IA

Built 1995 Load: 33.3 t ADT: 3,220

FM

Fair

Over: SPRUCE CREEK

087E43606, Jackson, IA

Built 1982 Load: 33.3 t ADT: 670

LOCAL

Fair

Over: BURR OAK CREEK

073080703, Jefferson, IA

Built 1978 Load: 33.3 t ADT: 20

LOCAL

Fair

Over: STREAM

073090702, Jefferson, IA

Built 1972 Load: 33.3 t ADT: 15

FM

Fair

Over: HOG THIEF HOLLOW

065052011, Lee, IA

Built 1958 Load: 33.3 t ADT: 280

LOCAL

Fair

Over: STREAM

077211203, Marion, IA

Built 1997 Load: 33.3 t ADT: 30

FM

Fair

Over: WHIPPERWILL CREEK

072191205, Monroe, IA

Built 1989 Load: 33.3 t ADT: 50

N AVENUE

Fair

Over: SNAKE CREEK

069372102, Page, IA

Built 1986 Load: 33.3 t ADT: 110

FM

Fair

Over: DD #114

097332605, Palo Alto, IA

Built 1982 Load: 33.3 t ADT: 81

IA 10

Fair

Over: BIG SIOUX RIVER

At S Dakota St. Line, Sioux, IA

Built 1991 Load: 33.3 t ADT: 1,910

LOCAL

Fair

Over: CREEK

070353204, Taylor, IA

Built 1957 Load: 33.3 t ADT: 34

LOCAL

Fair

Over: BUCKEYE CREEK

072121306, Wapello, IA

Built 1987 Load: 33.3 t ADT: 21

LOCAL

Fair

Over: STREAM

0894332, Woodbury, IA

Built 2006 Load: 33.3 t ADT: 30

LOCAL

Fair

Over: LITTLE CEDAR CREEK

095140503, Chickasaw, IA

Built 2005 Load: 33.4 t ADT: 16

FM

Fair

Over: SHELL ROCK RIVER

095183602, Floyd, IA

Built 1967 Load: 33.4 t ADT: 118

IA 175

Fair

Over: DRAINAGE DITCH

0.2 MI. E OF E JCT. US 69, Hamilton, IA

Built 1977 Load: 33.4 t ADT: 1,690

FM

Fair

Over: TRULINER CREEK

093292201, Humboldt, IA

Built 1937 Load: 33.4 t ADT: 649

LOCAL

Fair

Over: DRAINAGE

081090702, Iowa, IA

Built 1976 Load: 33.4 t ADT: 30

US 151

Fair

Over: CLEAR CREEK

1.9 MI. N OF JCT. I 80, Iowa, IA

Built 1984 Load: 33.4 t ADT: 1,510

FM 13TH ST

Fair

Over: SILVER CREEK

084E33203, Jackson, IA

Built 2000 Load: 33.4 t ADT: 246

FM

Fair

Over: S FORK MAQUOKETA RIVER

085E20704, Jackson, IA

Built 1961 Load: 33.4 t ADT: 60

US 169

Fair

Over: BLUE EARTH RIVER

0.5 mi. S of Jct. SR A16, Kossuth, IA

Built 1992 Load: 33.4 t ADT: 1,430

FM

Fair

Over: TOM CREEK

100432002, Lyon, IA

Built 1972 Load: 33.4 t ADT: 90

Showing 7,251-7,300 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.