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: CREEK

073113604, Jefferson, IA

Built 1967 Load: 22.6 t ADT: 1,120

FM

Fair

Over: SOUTH SKUNK RIVER

074100604, Keokuk, IA

Built 1969 Load: 22.6 t ADT: 220

FM

Fair

Over: SOUTH SKUNK RIVER

074120506, Keokuk, IA

Built 1966 Load: 22.6 t ADT: 60

LOC 130TH AVE

Fair

Over: DD #182

094283102, Kossuth, IA

Built 1979 Load: 22.6 t ADT: 50

LOC 110TH AVE

Fair

Over: OUTLET DD #94

094291104, Kossuth, IA

Built 1984 Load: 22.6 t ADT: 21

LOCAL

Fair

Over: BRANCH OF N CEDAR CREEK

073202404, Lucas, IA

Built 2008 Load: 22.6 t ADT: 21

FM

Fair

Over: CEDAR CREEK

072181203, Monroe, IA

Built 1963 Load: 22.6 t ADT: 310

FM

Fair

Over: OVER BNSF RR

071362003, Montgomery, IA

Built 1966 Load: 22.6 t ADT: 300

LOCAL

Fair

Over: LITTLE OCHEYEDAN RIVER

099402902, Osceola, IA

Built 1934 Load: 22.6 t ADT: 15

FM C-44

Fair

Over: BROKEN KETTLE CREEK

091481105, Plymouth, IA

Built 1965 Load: 22.6 t ADT: 120

FM

Fair

Over: W BR FLOYD RIVER

093453001, Plymouth, IA

Built 1968 Load: 22.6 t ADT: 270

FM-COLDWATER AV

Fair

Over: PIGEON CREEK

076430506, Pottawattamie, IA

Built 1966 Load: 22.6 t ADT: 638

LOCAL

Fair

Over: STREAM

067302403, Ringgold, IA

Built 1953 Load: 22.6 t ADT: 26

LOCAL ROAD

Fair

Over: BOYER RIVER

086370201, Sac, IA

Built 1969 Load: 22.6 t ADT: 30

FM

Fair

Over: WEST FORK LITTLE SIOUX

089442901, Woodbury, IA

Built 1969 Load: 22.6 t ADT: 309

LOCAL

Fair

Over: DD #121

093251501, Wright, IA

Built 1984 Load: 22.6 t ADT: 63

LOCAL

Fair

Over: WEST FORK NODAWAY RIVER

075330903, Adair, IA

Built 1955 Load: 22.7 t ADT: 21

FM

Fair

Over: OIL SPRINGS

097020712, Allamakee, IA

Built 1980 Load: 22.7 t ADT: 520

LOCAL RD

Fair

Over: BR YELLOW RIVER

097063404, Allamakee, IA

Built 1966 Load: 22.7 t ADT: 39

LOCAL

Fair

Over: CLEAR CREEK

099042704, Allamakee, IA

Built 1979 Load: 22.7 t ADT: 26

GIBSON RD

Fair

Over: TRIB TO BLACK HAWK CREEK

87-14-09-02-10, Black Hawk, IA

Built 1948 Load: 22.7 t ADT: 29

FM

Fair

Over: STREAM

87-14-07-04-10, Black Hawk, IA

Built 1950 Load: 22.7 t ADT: 34

FM

Fair

Over: OVFLW WAPSIPINICON RVR

089100909, Buchanan, IA

Built 1968 Load: 22.7 t ADT: 687

FM

Fair

Over: BRUSHY FORK CREEK

083353402, Carroll, IA

Built 1962 Load: 22.7 t ADT: 50

E13 110TH ST

Fair

Over: FIELD STREAM

085331201, Carroll, IA

Built 1973 Load: 22.7 t ADT: 60

LOCAL - 740TH

Fair

Over: ELM CREEK

074341602, Cass, IA

Built 1984 Load: 22.7 t ADT: 62

LOCAL - WICHITA

Fair

Over: SMALL CREEK

074342701, Cass, IA

Built 1986 Load: 22.7 t ADT: 15

LOCAL - UPLAND

Fair

Over: SMALL STREAM

074371501, Cass, IA

Built 1986 Load: 22.7 t ADT: 11

700TH ST

Fair

Over: CREEK

075351104, Cass, IA

Built 2014 Load: 22.7 t ADT: 5

LOCAL - 570TH

Fair

Over: WATERWAY

075373402, Cass, IA

Built 1988 Load: 22.7 t ADT: 15

LOCAL

Fair

Over: SEVENMILE CREEK

076341501, Cass, IA

Built 2006 Load: 22.7 t ADT: 51

700TH ST

Fair

Over: CREEK

076351404, Cass, IA

Built 2020 Load: 22.7 t ADT: 11

LOCAL - CHICAGO

Fair

Over: CREEK

077361701, Cass, IA

Built 1987 Load: 22.7 t ADT: 26

LOCAL/BUCK CRK

Fair

Over: CREEK

077361702, Cass, IA

Built 1988 Load: 22.7 t ADT: 30

390TH ST

Fair

Over: OVERFLOW LITTLE SIOUX R

095360201, Clay, IA

Built 1955 Load: 22.7 t ADT: 40

ECHO AVE

Fair

Over: HONEY CREEK

091050406, Clayton, IA

Built 1951 Load: 22.7 t ADT: 39

CHARIOT RD

Fair

Over: SM STREAM

093050506, Clayton, IA

Built 1957 Load: 22.7 t ADT: 34

DOLPHIN AVE

Fair

Over: SCHNEIDER CREEK

093052004, Clayton, IA

Built 1977 Load: 22.7 t ADT: 10

265TH ST

Fair

Over: SMALL STREAM

093052605, Clayton, IA

Built 1977 Load: 22.7 t ADT: 15

AGATE RD

Fair

Over: SMALL STREAM

094062103, Clayton, IA

Built 1978 Load: 22.7 t ADT: 295

125TH ST

Fair

Over: STREAM

095051603, Clayton, IA

Built 1957 Load: 22.7 t ADT: 73

125TH ST

Fair

Over: STREAM

095051605, Clayton, IA

Built 1957 Load: 22.7 t ADT: 82

DOVE AVE

Fair

Over: SILVER CREEK

095052902, Clayton, IA

Built 1984 Load: 22.7 t ADT: 41

120TH ST

Fair

Over: ROBERTS CREEK

095061601, Clayton, IA

Built 1900 Load: 22.7 t ADT: 98

215TH ST

Fair

Over: DRAINAGE DITCH 11

082E13601, Clinton, IA

Built 1988 Load: 22.7 t ADT: 26

PERSHING BLVD

Fair

Over: STREAM

082073005, Clinton, IA

Built 1975 Load: 22.7 t ADT: 754

N. 2ND ST.

Fair

Over: STREAM

082072902, Clinton, IA

Built 1975 Load: 22.7 t ADT: 1,223

LOCAL

Fair

Over: SMALL STREAM

082382302, Crawford, IA

Built 1937 Load: 22.7 t ADT: 62

LOCAL

Fair

Over: SMALL STREAM

068252806, Decatur, IA

Built 1997 Load: 22.7 t ADT: 30

IA 3

Fair

Over: PINE CREEK

6.9 MI.E OF JCT. IA 38, Delaware, IA

Built 1932 Load: 22.7 t ADT: 760

Showing 3,451-3,500 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.