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

Good

Over: TRIB. TO SOAP CREEK

070152107, Davis, IA

Built 2001 Load: 20.5 t ADT: 20

LOCAL

Good

Over: BR FISH CREEK

070062004, Henry, IA

Built 2002 Load: 20.5 t ADT: 5

LOCAL

Good

Over: SMALL STREAM

094431602, Sioux, IA

Built 1977 Load: 20.5 t ADT: 26

LOCAL

Good

Over: SMALL STREAM

094433002, Sioux, IA

Built 1938 Load: 20.5 t ADT: 50

LOCAL

Good

Over: SMALL STREAM

094442602, Sioux, IA

Built 1977 Load: 20.5 t ADT: 45

LOCAL

Good

Over: SMALL STREAM

094450701, Sioux, IA

Built 1937 Load: 20.5 t ADT: 20

LOCAL

Good

Over: SMALL STREAM

094451102, Sioux, IA

Built 2002 Load: 20.5 t ADT: 40

LOCAL

Good

Over: SMALL STREAM

094452801, Sioux, IA

Built 1982 Load: 20.5 t ADT: 71

LOCAL

Good

Over: SMALL

094470402, Sioux, IA

Built 1978 Load: 20.5 t ADT: 50

LOCAL

Good

Over: SMALL

094470402, Sioux, IA

Built 1980 Load: 20.5 t ADT: 50

LOCAL

Good

Over: SMALL STREAM

094472301, Sioux, IA

Built 1977 Load: 20.5 t ADT: 26

LOCAL

Good

Over: SMALL STREAM

094473402, Sioux, IA

Built 1948 Load: 20.5 t ADT: 30

LOCAL

Good

Over: SMALL

094473402, Sioux, IA

Built 1980 Load: 20.5 t ADT: 30

LOCAL

Good

Over: SMALL STREAM

095430102, Sioux, IA

Built 1940 Load: 20.5 t ADT: 20

LOCAL

Good

Over: SMALL

095441701, Sioux, IA

Built 1979 Load: 20.5 t ADT: 45

LOCAL

Good

Over: STREAM

095450102, Sioux, IA

Built 1978 Load: 20.5 t ADT: 131

LOCAL

Good

Over: SIXMILE CREEK

095460302, Sioux, IA

Built 1937 Load: 20.5 t ADT: 71

LOCAL

Good

Over: SMALL STREAM

095460901, Sioux, IA

Built 1938 Load: 20.5 t ADT: 80

LOCAL

Good

Over: SMALL STREAM

095460902, Sioux, IA

Built 1947 Load: 20.5 t ADT: 60

LOCAL RD

Good

Over: SIX MILE CREEK

095471801, Sioux, IA

Built 1992 Load: 20.5 t ADT: 15

LOCAL

Good

Over: DRY CREEK

095473101, Sioux, IA

Built 1938 Load: 20.5 t ADT: 60

LOCAL

Good

Over: SMALL STREAM

096441801, Sioux, IA

Built 1938 Load: 20.5 t ADT: 15

LOCAL

Good

Over: NO NAME CREEK

096441802, Sioux, IA

Built 1900 Load: 20.5 t ADT: 40

LOCAL

Good

Over: SMALL

096450702, Sioux, IA

Built 1940 Load: 20.5 t ADT: 45

LOCAL

Good

Over: SMALL

096461902, Sioux, IA

Built 1978 Load: 20.5 t ADT: 20

LOCAL

Good

Over: SMALL STREAM

096463502, Sioux, IA

Built 1938 Load: 20.5 t ADT: 40

LOCAL

Good

Over: SMALL

097431801, Sioux, IA

Built 1941 Load: 20.5 t ADT: 15

LOCAL

Good

Over: SM STREAM

097433502, Sioux, IA

Built 1937 Load: 20.5 t ADT: 34

LOCAL

Good

Over: SM STREAM

097440101, Sioux, IA

Built 2002 Load: 20.5 t ADT: 20

LOCAL

Good

Over: SM STREAM

097440501, Sioux, IA

Built 1977 Load: 20.5 t ADT: 26

LOCAL

Good

Over: SM STREAM

097450102, Sioux, IA

Built 1977 Load: 20.5 t ADT: 60

LOCAL

Good

Over: SM STREAM

097450401, Sioux, IA

Built 1931 Load: 20.5 t ADT: 20

LOCAL

Good

Over: SM STREAM

097450702, Sioux, IA

Built 1947 Load: 20.5 t ADT: 40

LOCAL

Good

Over: SMALL

097452301, Sioux, IA

Built 1978 Load: 20.5 t ADT: 34

LOCAL

Good

Over: SMALL

097453002, Sioux, IA

Built 1980 Load: 20.5 t ADT: 80

US 63

Good

Over: MINNOW CREEK

1.3 MILES N OF JCT US 30, Tama, IA

Built 1976 Load: 20.5 t ADT: 3,830

NEWTON AVE

Good

Over: CROOKED CREEK

079020504, Cedar, IA

Built 2017 Load: 20.6 t ADT: 15

FM

Good

Over: SOLDIER RIVER

085412001, Crawford, IA

Built 1957 Load: 20.6 t ADT: 627

LOCAL

Good

Over: ROCK CREEK

076120705, Keokuk, IA

Built 1998 Load: 20.6 t ADT: 50

IA 471

Good

Over: BRANCH BOYER RIVER

0.7 mi. N of jct. IA 175, Sac, IA

Built 1984 Load: 20.6 t ADT: 1,070

J AVE

Good

Over: WOLF CREEK

085151502, Tama, IA

Built 2014 Load: 20.6 t ADT: 15

MANAWA TRAIL RD

Good

Over: CANOE CREEK

099072905, Winneshiek, IA

Built 1979 Load: 20.6 t ADT: 59

LOCAL

Good

Over: CANOE CREEK

099080706, Winneshiek, IA

Built 1985 Load: 20.6 t ADT: 44

LOCAL

Good

Over: SMALL CREEK

099101502, Winneshiek, IA

Built 1979 Load: 20.6 t ADT: 29

LOCAL

Good

Over: SMALL CREEK

100090802, Winneshiek, IA

Built 1985 Load: 20.6 t ADT: 49

FM

Good

Over: PINE CREEK

100091801, Winneshiek, IA

Built 1985 Load: 20.6 t ADT: 49

221ST ST

Good

Over: SMALL STREAM

088040303, Delaware, IA

Built 2007 Load: 20.7 t ADT: 44

FM

Good

Over: LITTLE MAQUOKETA RIVER

089E11107, Dubuque, IA

Built 2006 Load: 20.7 t ADT: 314

IA 9

Good

Over: OTTER CREEK

2.5 mi. W of jct. SR L40, Osceola, IA

Built 1989 Load: 20.7 t ADT: 1,750

LOCAL

Good

Over: W FK W NISHNABOTNA RIVER

083372802, Crawford, IA

Built 1938 Load: 20.9 t ADT: 26

Showing 9,201-9,250 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.