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

LCL-340TH ST

Fair

Over: LOCAL CREEK

071413502, Mills, IA

Built 1968 Load: 32.7 t ADT: 5

FM-390TH ST

Fair

Over: DOUGLAS CREEK

072401502, Mills, IA

Built 1979 Load: 32.7 t ADT: 89

FA-JAMISON ROAD

Fair

Over: DRAINAGE

072402107, Mills, IA

Built 1993 Load: 32.7 t ADT: 349

LCL-302ND ST

Fair

Over: OSBORN CREEK

072410604, Mills, IA

Built 1979 Load: 32.7 t ADT: 34

KIDD ROAD

Fair

Over: SMALL STREAM

072421806, Mills, IA

Built 1985 Load: 32.7 t ADT: 270

LCL-240TH ST

Fair

Over: SMALL STREAM

072431208, Mills, IA

Built 1987 Load: 32.7 t ADT: 120

LCL-KANE AVE

Fair

Over: DRAINAGE

072433001, Mills, IA

Built 1970 Load: 32.7 t ADT: 26

LCL-COMPASS AVE

Fair

Over: ROAD DITCH DRAINAGE

073401507, Mills, IA

Built 1964 Load: 32.7 t ADT: 5

LCL-APPLEWOOD

Fair

Over: STREAM

073410301, Mills, IA

Built 1988 Load: 32.7 t ADT: 15

LCL-307TH ST

Fair

Over: STREAM

073411906, Mills, IA

Built 1967 Load: 32.7 t ADT: 11

LCL-DONNER AVE

Fair

Over: STREAM

073412303, Mills, IA

Built 1970 Load: 32.7 t ADT: 26

LCL-345TH ST

Fair

Over: STREAM

073412306, Mills, IA

Built 1998 Load: 32.7 t ADT: 26

LCL-EPPERSON AV

Fair

Over: CREEK

073413005, Mills, IA

Built 1968 Load: 32.7 t ADT: 20

FA-BARRUS RD

Fair

Over: SNAKE CREEK

073420903, Mills, IA

Built 1998 Load: 32.7 t ADT: 358

LCL-QUIGG AV

Fair

Over: WAUBONSIE CREEK

071432507, Mills, IA

Built 1976 Load: 32.7 t ADT: 26

340TH

Fair

Over: CREEK

097160101, Mitchell, IA

Built 1972 Load: 32.7 t ADT: 20

340TH

Fair

Over: CREEK

097170401, Mitchell, IA

Built 2001 Load: 32.7 t ADT: 78

400TH

Fair

Over: SOAP CREEK

098150401, Mitchell, IA

Built 1992 Load: 32.7 t ADT: 15

390TH

Fair

Over: WAPSIPINICON RIVER

098151203, Mitchell, IA

Built 1995 Load: 32.7 t ADT: 33

UNDERWOOD AVE

Fair

Over: CREEK

098153302, Mitchell, IA

Built 1994 Load: 32.7 t ADT: 570

NOBLE AVE

Fair

Over: SPRING CREEK

098162002, Mitchell, IA

Built 2002 Load: 32.7 t ADT: 49

460TH ST

Fair

Over: WAPSIPINICON

099150301, Mitchell, IA

Built 1983 Load: 32.7 t ADT: 118

490TH

Fair

Over: CREEK

100162201, Mitchell, IA

Built 1992 Load: 32.7 t ADT: 44

LOCAL

Fair

Over: BIG CEDAR RIVER

100180801, Mitchell, IA

Built 1978 Load: 32.7 t ADT: 49

ECHO AVE

Fair

Over: OTTER CREEK

100182302, Mitchell, IA

Built 1930 Load: 32.7 t ADT: 59

FM

Fair

Over: NEW FARMER MAIN D.D.

084450301, Monona, IA

Built 2002 Load: 32.7 t ADT: 50

LOCAL

Fair

Over: STREAM

084451104, Monona, IA

Built 2002 Load: 32.7 t ADT: 15

LOCAL

Fair

Over: MILLER CREEK

072170206, Monroe, IA

Built 1989 Load: 32.7 t ADT: 100

586TH AVE

Fair

Over: CREEK

072180305, Monroe, IA

Built 1989 Load: 32.7 t ADT: 30

LOCAL

Fair

Over: GRAYS CREEK

073172702, Monroe, IA

Built 2003 Load: 32.7 t ADT: 45

FM

Fair

Over: WHIPPOORWILL CREEK

073192203, Monroe, IA

Built 1992 Load: 32.7 t ADT: 45

LOCAL

Fair

Over: MIDDLE AVERY CREEK

072161905, Monroe, IA

Built 1989 Load: 32.7 t ADT: 40

FM

Fair

Over: TARKIO CK

072372601, Montgomery, IA

Built 1977 Load: 32.7 t ADT: 338

FM

Fair

Over: LITTLE TARKIO CREEK

072382507, Montgomery, IA

Built 1993 Load: 32.7 t ADT: 509

FM

Fair

Over: CRANE CREEK

077032806, Muscatine, IA

Built 1993 Load: 32.7 t ADT: 400

LOCAL

Fair

Over: SMALL UN-NAMED CREEK

094403102, O'Brien, IA

Built 1974 Load: 32.7 t ADT: 62

LOCAL

Fair

Over: SMALL UN-NAMED CREEK

094403202, O'Brien, IA

Built 1973 Load: 32.7 t ADT: 35

LOCAL

Fair

Over: W BR WHISKEY CREEK

094413102, O'Brien, IA

Built 1978 Load: 32.7 t ADT: 21

LOCAL

Fair

Over: BARRY CREEK

095392801, O'Brien, IA

Built 1980 Load: 32.7 t ADT: 41

LOCAL

Fair

Over: MCCREATH CREEK

095392801, O'Brien, IA

Built 1980 Load: 32.7 t ADT: 41

FM

Fair

Over: STOFFERAN CREEK

095420301, O'Brien, IA

Built 1971 Load: 32.7 t ADT: 968

FM

Fair

Over: WILLOW CREEK

095420801, O'Brien, IA

Built 1972 Load: 32.7 t ADT: 828

FM

Fair

Over: LITTLE WATERMAN CREEK

096402301, O'Brien, IA

Built 1955 Load: 32.7 t ADT: 300

FM

Fair

Over: WATERMAN CREEK

097401101, O'Brien, IA

Built 2004 Load: 32.7 t ADT: 30

FM

Fair

Over: ENGELS CREEK

097422302, O'Brien, IA

Built 1925 Load: 32.7 t ADT: 199

ORIOLE AVE

Fair

Over: GRASS WATERWAY

096410702, O'Brien, IA

Built 1965 Load: 32.7 t ADT: 409

US 18

Fair

Over: STREAM

1.6 mi. W of jct. SR M12, O'Brien, IA

Built 1958 Load: 32.7 t ADT: 3,530

US 59

Fair

Over: JOHNSON RUN CREEK

1.1 MI. N OF JCT. IA. 2, Page, IA

Built 1960 Load: 32.7 t ADT: 7,900

305TH STREET

Fair

Over: STREAM

067362207, Page, IA

Built 1990 Load: 32.7 t ADT: 29

270TH STREET

Fair

Over: MIDDLE MILL CREEK

067370401, Page, IA

Built 1987 Load: 32.7 t ADT: 45

Showing 6,801-6,850 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.