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

FM

Fair

Over: DRAINAGE WAY

094391501, O'Brien, IA

Built 1946 Load: 18.1 t ADT: 60

LOCAL SEC RD

Fair

Over: NELSON CREEK

094412402, O'Brien, IA

Built 1941 Load: 18.1 t ADT: 41

LOCAL

Fair

Over: DRY RUN

095400701, O'Brien, IA

Built 1947 Load: 18.1 t ADT: 50

LOCAL

Fair

Over: MILL CREEK

096412401, O'Brien, IA

Built 1939 Load: 18.1 t ADT: 41

US 18

Fair

Over: STREAM

0.2 mi. W of SR M22, O'Brien, IA

Built 1959 Load: 18.1 t ADT: 3,210

NB US 75

Fair

Over: STREAM

1.3 mi N of SR C60, Plymouth, IA

Built 1950 Load: 18.1 t ADT: 7,000

IA 140

Fair

Over: DRAINAGE

1.4 S of S.R. C38, Plymouth, IA

Built 1963 Load: 18.1 t ADT: 970

LOCAL

Fair

Over: BIG CEDAR CREEK DD #181

091342502, Pocahontas, IA

Built 1960 Load: 18.1 t ADT: 34

US 6

Fair

Over: DRAINAGE DITCH

0.9 MILE W OF W JCT IA 28, Polk, IA

Built 1937 Load: 18.1 t ADT: 20,100

I-35 & I-80

Fair

Over: N WALNUT CREEK

1.1 MILES E OF JCT IA 141, Polk, IA

Built 1958 Load: 18.1 t ADT: 79,500

FM S.E.124TH

Fair

Over: CAMP CREEK

078222404, Polk, IA

Built 1954 Load: 18.1 t ADT: 71

IA 92

Fair

Over: NATURAL CREEK

0.3 MI. E OF SR L-35, Pottawattamie, IA

Built 1953 Load: 18.1 t ADT: 13,000

IA 92

Fair

Over: PONY CREEK

3.7 MI. E OF I-29, Pottawattamie, IA

Built 1953 Load: 18.1 t ADT: 5,700

NB I-29

Fair

Over: DRAINAGE DITCH

0.3 mi. N of Jct. IA 192, Pottawattamie, IA

Built 1958 Load: 18.1 t ADT: 7,100

I 80 & US 6

Fair

Over: LITTLE MOSQUITO CREEK

1.6 mi. W of Jct. U.S. 6, Pottawattamie, IA

Built 1966 Load: 18.1 t ADT: 31,100

US 6

Fair

Over: STREAM

3.1 MI. E of Jct. IA 146, Poweshiek, IA

Built 1951 Load: 18.1 t ADT: 2,970

IA 21

Fair

Over: WOLF CREEK

1.0 MILES N OF JCT I-80, Poweshiek, IA

Built 1962 Load: 18.1 t ADT: 1,300

IA 471

Fair

Over: DRAINAGE DITCH

0.2 mi. N of SR D-36, Sac, IA

Built 1933 Load: 18.1 t ADT: 1,320

IA 39

Fair

Over: NATURAL STREAM

2.6 mi. S of SR D59, Sac, IA

Built 1951 Load: 18.1 t ADT: 1,540

IA 461

Fair

Over: BLACK HAWK CREEK

1.3 MI. E OF IOWA #22, Scott, IA

Built 1957 Load: 18.1 t ADT: 9,800

FM

Fair

Over: LITTLE SILVER CREEK

078403405, Shelby, IA

Built 1958 Load: 18.1 t ADT: 110

LOCAL

Fair

Over: SMALL STREAM

802340, Shelby, IA

Built 1959 Load: 18.1 t ADT: 51

LOCAL

Fair

Over: LONG BRANCH CREEK

081372401, Shelby, IA

Built 1956 Load: 18.1 t ADT: 26

FM

Fair

Over: LONG BRANCH

081372602, Shelby, IA

Built 1957 Load: 18.1 t ADT: 45

FM

Fair

Over: LONG BRANCH

081373401, Shelby, IA

Built 1956 Load: 18.1 t ADT: 537

270TH ST

Fair

Over: DRAINAGE

083233303, Story, IA

Built 1950 Load: 18.1 t ADT: 34

730TH AVE

Fair

Over: HARDIN-STORY DD 1

085211204, Story, IA

Built 1967 Load: 18.1 t ADT: 30

140TH ST

Fair

Over: DRAINAGE DITCH

085242701, Story, IA

Built 1963 Load: 18.1 t ADT: 34

MATHEWS ST

Fair

Over: DRAINAGE DITCH #70

000000000, Story, IA

Built 1969 Load: 18.1 t ADT: 1,626

US 63

Fair

Over: ROCK CREEK

1.9 MI. N OF N JCT SR D65, Tama, IA

Built 1955 Load: 18.1 t ADT: 3,500

FM

Fair

Over: PLATTE RIVER DITCH

067321203, Taylor, IA

Built 1958 Load: 18.1 t ADT: 79

LOCAL

Fair

Over: SMALL STREAM

069342502, Taylor, IA

Built 1996 Load: 18.1 t ADT: 34

FM

Fair

Over: CREEK

068110702, Van Buren, IA

Built 1952 Load: 18.1 t ADT: 45

FM

Fair

Over: CHEQUEST CREEK

069102106, Van Buren, IA

Built 1958 Load: 18.1 t ADT: 110

LOCAL

Fair

Over: CHEQUEST CREEK

069111803, Van Buren, IA

Built 1978 Load: 18.1 t ADT: 60

FM

Fair

Over: CEDAR CREEK

070080204, Van Buren, IA

Built 1958 Load: 18.1 t ADT: 80

IA 92

Fair

Over: STREAM

1.9 MI. E OF IA. 28, Warren, IA

Built 1928 Load: 18.1 t ADT: 3,070

LOCAL

Fair

Over: SMALL CREEK

077240200, Warren, IA

Built 1980 Load: 18.1 t ADT: 875

LOCAL

Fair

Over: SM STREAM

077081204, Washington, IA

Built 1973 Load: 18.1 t ADT: 140

FM

Fair

Over: CREEK

096080805, Winneshiek, IA

Built 1973 Load: 18.1 t ADT: 795

FM

Fair

Over: TANGEN CREEK

096082804, Winneshiek, IA

Built 1961 Load: 18.1 t ADT: 59

V 64

Fair

Over: CREEK

096102003, Winneshiek, IA

Built 1957 Load: 18.1 t ADT: 471

FM

Fair

Over: YELLOW RIVER N FORK

097073104, Winneshiek, IA

Built 1962 Load: 18.1 t ADT: 740

FM

Fair

Over: TROUT CREEK

097080504, Winneshiek, IA

Built 1962 Load: 18.1 t ADT: 894

FM

Fair

Over: TURKEY RIVER

097091808, Winneshiek, IA

Built 1955 Load: 18.1 t ADT: 658

FM

Fair

Over: STREAM

098082812, Winneshiek, IA

Built 1958 Load: 18.1 t ADT: 1,169

FM

Fair

Over: TEN MILE CREEK

098100102, Winneshiek, IA

Built 1952 Load: 18.1 t ADT: 236

FM

Fair

Over: TEN MILE CREEK BRANCH

098101302, Winneshiek, IA

Built 1968 Load: 18.1 t ADT: 410

FM

Fair

Over: CANOE CREEK

099072604, Winneshiek, IA

Built 1935 Load: 18.1 t ADT: 147

337TH ST

Fair

Over: CANOE CREEK BRANCH

099080103, Winneshiek, IA

Built 1971 Load: 18.1 t ADT: 265

Showing 2,151-2,200 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.