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

F65 WHITE POLE RD

Fair

Over: BRANCH MIDDLE RIVER

078313203, Guthrie, IA

Built 1973 Load: 33.7 t ADT: 916

LOCAL

Fair

Over: TRIB TO MIDDLE RIVER

079333504, Guthrie, IA

Built 1984 Load: 33.7 t ADT: 11

NB I-29

Fair

Over: OLD SOLDIER RIVER DITCH

4.0 mi. S of IA 127, Harrison, IA

Built 1967 Load: 33.7 t ADT: 7,600

LOCAL

Fair

Over: BIG CREEK

072063504, Henry, IA

Built 1985 Load: 33.7 t ADT: 25

FM DOUGLAS AVE

Fair

Over: LITTLE WAPSIPINICON

098140304, Howard, IA

Built 1951 Load: 33.7 t ADT: 88

75TH AVE.

Fair

Over: SMALL CREEK

083020104, Jones, IA

Built 2006 Load: 33.7 t ADT: 62

BLAIRS FERRY RD

Fair

Over: RED CEDAR RIVER

084082105, Linn, IA

Built 1984 Load: 33.7 t ADT: 4,419

BLAIRS FERRY RD

Fair

Over: MUD LAKE

084082205, Linn, IA

Built 1984 Load: 33.7 t ADT: 4,419

US 61

Fair

Over: MILLRACE CREEK

5.9 mi S of S Jct IA 92, Louisa, IA

Built 1985 Load: 33.7 t ADT: 4,950

LOCAL

Fair

Over: N COAL CREEK

074170404, Mahaska, IA

Built 1950 Load: 33.7 t ADT: 60

LCL-RIST AVE

Fair

Over: CREEK

071433403, Mills, IA

Built 1972 Load: 33.7 t ADT: 15

N.E.DELAWARE AV

Fair

Over: FOUR MILE CREEK

080230700, Polk, IA

Built 1982 Load: 33.7 t ADT: 5,650

CO RD G18

Fair

Over: KEG CREEK

077411416, Pottawattamie, IA

Built 1990 Load: 33.7 t ADT: 658

MCPHERSON AVE

Fair

Over: LITTLE MOSQUITO CREEK

000000000, Pottawattamie, IA

Built 1989 Load: 33.7 t ADT: 2,690

LOCAL

Fair

Over: STREAM

070311403, Ringgold, IA

Built 1941 Load: 33.7 t ADT: 11

FM

Fair

Over: INDIAN CREEK

078370509, Shelby, IA

Built 1965 Load: 33.7 t ADT: 240

FM

Fair

Over: W FORK FLOYD RIVER

095451201, Sioux, IA

Built 1967 Load: 33.7 t ADT: 2,992

FM

Fair

Over: DRY CREEK

095471901, Sioux, IA

Built 1966 Load: 33.7 t ADT: 538

310TH ST

Fair

Over: ROCK CREEK

082222301, Story, IA

Built 1988 Load: 33.7 t ADT: 40

180TH ST/E29

Fair

Over: RICHLAND 81 OPEN DITCH

084222201, Story, IA

Built 2009 Load: 33.7 t ADT: 1,028

FM

Fair

Over: SMALL STREAM

088281706, Webster, IA

Built 1965 Load: 33.7 t ADT: 199

LOCAL

Fair

Over: CREEK

098091505, Winneshiek, IA

Built 1989 Load: 33.7 t ADT: 5

WHEELERWOOD

Fair

Over: STREAM

098212002, Worth, IA

Built 1961 Load: 33.7 t ADT: 265

LOCAL

Fair

Over: D.D. 107

093250901, Wright, IA

Built 1997 Load: 33.7 t ADT: 63

S CANFIELD RD

Fair

Over: TRIB TO INDIAN CREEK

88-11-08-04-10, Black Hawk, IA

Built 1996 Load: 33.8 t ADT: 2,769

370TH AVE

Fair

Over: STREAM

096382501, Clay, IA

Built 2000 Load: 33.8 t ADT: 30

HWY 99

Fair

Over: DRAINAGE DITCH

074033608, Louisa, IA

Built 1954 Load: 33.8 t ADT: 490

JEFFERSON ST

Fair

Over: MCLAREN CREEK

098471800, Lyon, IA

Built 1968 Load: 33.8 t ADT: 201

FM

Fair

Over: CREEK

077012804, Muscatine, IA

Built 1970 Load: 33.8 t ADT: 490

230TH STREET

Fair

Over: STREAM

068391301, Page, IA

Built 1986 Load: 33.8 t ADT: 26

LOCAL

Fair

Over: CREEK

078363101, Audubon, IA

Built 1939 Load: 33.9 t ADT: 30

COTTER RD

Fair

Over: MILLER CREEK

87-12-04-02-10, Black Hawk, IA

Built 1986 Load: 33.9 t ADT: 59

LINCOLN RD

Fair

Over: TRIB TO BLACK HAWK CREEK

87-14-15-02-10, Black Hawk, IA

Built 1985 Load: 33.9 t ADT: 59

HOLMES RD

Fair

Over: TRIB TO ROCK CREEK

87-14-24-02-10, Black Hawk, IA

Built 1985 Load: 33.9 t ADT: 39

LOCAL ROAD

Fair

Over: BRANCH BLACKHAWK CREEK

087150402, Grundy, IA

Built 1966 Load: 33.9 t ADT: 59

FM

Fair

Over: MIDDLE RACCOON RIVER

079300906, Guthrie, IA

Built 1992 Load: 33.9 t ADT: 927

W BENTON ST

Fair

Over: WILLOW CREEK

079061700, Johnson, IA

Built 1971 Load: 33.9 t ADT: 6,100

NB US 218

Fair

Over: OLD MAN CREEK OVERFLOW

0.6 mi. N of Observ. Ave, Johnson, IA

Built 1983 Load: 33.9 t ADT: 10,250

NB I-380

Fair

Over: CC RR & ASH PIT

2.9 MI. S OF JCT. IA 100, Linn, IA

Built 1979 Load: 33.9 t ADT: 32,300

LOCAL

Fair

Over: NODAWAY RIVER

071362104, Montgomery, IA

Built 1993 Load: 33.9 t ADT: 60

LOCAL-CASS#104B

Fair

Over: TARKIO CREEK

073370201, Montgomery, IA

Built 1990 Load: 33.9 t ADT: 11

LOCAL

Fair

Over: WILLOW CREEK

093443602, Plymouth, IA

Built 1967 Load: 33.9 t ADT: 319

FM

Fair

Over: SMALL

078151704, Poweshiek, IA

Built 1978 Load: 33.9 t ADT: 45

170TH ST

Fair

Over: SMALL

084240701, Story, IA

Built 2006 Load: 33.9 t ADT: 1,137

FM

Fair

Over: PAINT CREEK

097042203, Allamakee, IA

Built 1964 Load: 34.0 t ADT: 442

FM

Fair

Over: CREEK

080343501, Audubon, IA

Built 1936 Load: 34.0 t ADT: 11

455TH ST

Fair

Over: MONTGOMERY CREEK

094360203, Clay, IA

Built 2002 Load: 34.0 t ADT: 62

FM

Fair

Over: TRIB GRAND RIVER

070273604, Decatur, IA

Built 1967 Load: 34.0 t ADT: 50

FM

Fair

Over: LITTLE SIOUX RIVER

099370802, Dickinson, IA

Built 1970 Load: 34.0 t ADT: 81

IA 127 & 183

Fair

Over: STEER CREEK

0.5 mi. E of IA 183, Harrison, IA

Built 1968 Load: 34.0 t ADT: 920

Showing 7,351-7,400 of 20,753 bridges

Related

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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.