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: KNOTTY CREEK

071023101, Des Moines, IA

Built 1972 Load: 18.0 t ADT: 150

LOCAL

Fair

Over: FLINT RIVER

071042206, Des Moines, IA

Built 1950 Load: 18.0 t ADT: 47

LOCAL

Fair

Over: PRAIRIE CREEK

087E23004, Dubuque, IA

Built 1946 Load: 18.0 t ADT: 45

950 150TH ST

Fair

Over: WEST OTTER CREEK,DD 26

094251001, Hancock, IA

Built 1976 Load: 18.0 t ADT: 41

LOCAL

Fair

Over: MAPLE RIVER

087402004, Ida, IA

Built 1978 Load: 18.0 t ADT: 267

FM

Fair

Over: NORTH FORK ENGLISH RIVER

078102001, Iowa, IA

Built 1960 Load: 18.0 t ADT: 70

FM

Fair

Over: PLEASANT CREEK

085E50704, Jackson, IA

Built 1958 Load: 18.0 t ADT: 50

LOCAL

Fair

Over: SUGAR CREEK

080213509, Jasper, IA

Built 1936 Load: 18.0 t ADT: 62

LOCAL

Fair

Over: TURKEY CREEK

072081104, Jefferson, IA

Built 1966 Load: 18.0 t ADT: 26

SE WHITE OAK AV

Fair

Over: BIG SLOUGH CR

078051104, Johnson, IA

Built 1920 Load: 18.0 t ADT: 35

FM

Fair

Over: GRAPE CREEK

066053006, Lee, IA

Built 1948 Load: 18.0 t ADT: 80

FM

Fair

Over: PAINTER CREEK

067061304, Lee, IA

Built 1948 Load: 18.0 t ADT: 45

LOCAL

Fair

Over: BLUFF CREEK

074172402, Mahaska, IA

Built 1948 Load: 18.0 t ADT: 50

LCL-LYTLE AVE

Fair

Over: SILVER CREEK

072413205, Mills, IA

Built 1983 Load: 18.0 t ADT: 71

LOCAL

Fair

Over: CEDAR CREEK

072180204, Monroe, IA

Built 1981 Load: 18.0 t ADT: 45

FM

Fair

Over: INDIAN CREEK TRIB

073392202, Montgomery, IA

Built 1957 Load: 18.0 t ADT: 131

LOCAL

Fair

Over: WAPSIPINICON CREEK

077040203, Muscatine, IA

Built 1975 Load: 18.0 t ADT: 62

FM

Fair

Over: DRY RUN

099393101, Osceola, IA

Built 1949 Load: 18.0 t ADT: 34

LOCAL

Fair

Over: STREAM

099403001, Osceola, IA

Built 1950 Load: 18.0 t ADT: 21

LOCAL

Fair

Over: OTTER CREEK

099413002, Osceola, IA

Built 1951 Load: 18.0 t ADT: 81

LOCAL

Fair

Over: STREAM

099413201, Osceola, IA

Built 1935 Load: 18.0 t ADT: 90

FM

Fair

Over: BIG CEDAR CK DD #181

091331802, Pocahontas, IA

Built 1965 Load: 18.0 t ADT: 20

LOCAL ROAD

Fair

Over: DITCH

081222902, Polk, IA

Built 1969 Load: 18.0 t ADT: 60

LOCAL

Fair

Over: STREAM

067280702, Ringgold, IA

Built 1994 Load: 18.0 t ADT: 11

FM

Fair

Over: DRAINAGE DITCH

069332302, Taylor, IA

Built 1954 Load: 18.0 t ADT: 15

LOCAL

Fair

Over: BUTCHER CREEK

077222002, Warren, IA

Built 1966 Load: 18.0 t ADT: 62

IA 92

Fair

Over: DUTCH CREEK

0.5 MI. E Jct. SR V15, Washington, IA

Built 1923 Load: 18.0 t ADT: 1,780

LOCAL

Fair

Over: WILLIAMS CR

074063102, Washington, IA

Built 1972 Load: 18.0 t ADT: 40

LOCAL

Fair

Over: WILLIAMS CR

074063202, Washington, IA

Built 1972 Load: 18.0 t ADT: 30

LOCAL ROAD

Fair

Over: SMALL STREAM

076091602, Washington, IA

Built 1970 Load: 18.0 t ADT: 40

LOCAL

Fair

Over: CAMP CR

077083604, Washington, IA

Built 1974 Load: 18.0 t ADT: 140

LOCAL RD

Fair

Over: SMALL

097071701, Winneshiek, IA

Built 1978 Load: 18.0 t ADT: 70

LOCAL LEGNO

Fair

Over: CREEK

100092704, Winneshiek, IA

Built 1960 Load: 18.0 t ADT: 5

LOCAL ROAD

Fair

Over: CREEK

100101202, Winneshiek, IA

Built 1900 Load: 18.0 t ADT: 29

IA 3

Fair

Over: EAGLE CREEK

5.3 mi. E of E jct. IA 17, Wright, IA

Built 1932 Load: 18.0 t ADT: 3,450

YELLOW RVR SF

Fair

Over: PAINT CREEK

A00140330, Allamakee, IA

Built 1960 Load: 18.1 t ADT: 80

FM

Fair

Over: NISHNABOTNA

078351905, Audubon, IA

Built 1959 Load: 18.1 t ADT: 170

FM M-66

Fair

Over: CREEK

080360808, Audubon, IA

Built 1958 Load: 18.1 t ADT: 338

FM

Fair

Over: NISHNABOTNA RIVER

078350409, Audubon, IA

Built 1958 Load: 18.1 t ADT: 597

IA 21

Fair

Over: STREAM

0.4 MI. S OF JCT. SR D52, Black Hawk, IA

Built 1959 Load: 18.1 t ADT: 2,600

IA 21

Fair

Over: STREAM

4.6 MI. S OF JCT. US 20, Black Hawk, IA

Built 1959 Load: 18.1 t ADT: 2,480

E QUARRY RD

Fair

Over: MILLER CREEK

87-12-18-01-10, Black Hawk, IA

Built 1961 Load: 18.1 t ADT: 33

YOUNG RD

Fair

Over: TRIB TO INDIAN CREEK

88-11-08-01-10, Black Hawk, IA

Built 1968 Load: 18.1 t ADT: 29

IA 210

Fair

Over: TRIB OF BIG CREEK

1.4 MI. E OF E JCT. IA 17, Boone, IA

Built 1966 Load: 18.1 t ADT: 2,230

IA 144

Fair

Over: STREAM

0.4 MILES N OF JCT SR P54, Boone, IA

Built 1941 Load: 18.1 t ADT: 1,690

IA 187

Fair

Over: STREAM

0.2 mi. N of Jct. SR C57, Buchanan, IA

Built 1960 Load: 18.1 t ADT: 1,560

IA 38

Fair

Over: STREAM

2.5 mi. S of jct. IA 130, Cedar, IA

Built 1956 Load: 18.1 t ADT: 3,360

FM

Fair

Over: SUGAR CREEK

079021101, Cedar, IA

Built 1958 Load: 18.1 t ADT: 230

US 18

Fair

Over: WILLOW CREEK

0.3 MI. W OF Jct. I-35, Cerro Gordo, IA

Built 1952 Load: 18.1 t ADT: 14,400

I-35

Fair

Over: WILLOW CREEK

0.2 MILES S OF N JCT. 18, Cerro Gordo, IA

Built 1971 Load: 18.1 t ADT: 16,800

Showing 2,051-2,100 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.