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

CHARIOT RD

Fair

Over: SMALL STREAM

094063510, Clayton, IA

Built 1956 Load: 26.2 t ADT: 49

DIPLOMAT RD

Fair

Over: HICKORY CREEK

095050610, Clayton, IA

Built 1953 Load: 26.2 t ADT: 511

DOLPHIN AVE

Fair

Over: STREAM

095052004, Clayton, IA

Built 1953 Load: 26.2 t ADT: 88

EAGLE RD

Fair

Over: STREAM

095053306, Clayton, IA

Built 1955 Load: 26.2 t ADT: 69

LOCAL

Fair

Over: SOUTH WILLOW CREEK

082411801, Crawford, IA

Built 1976 Load: 26.2 t ADT: 15

FM

Fair

Over: BEAVER CREEK

081270904, Dallas, IA

Built 1962 Load: 26.2 t ADT: 488

FM RIDGE RD

Fair

Over: ALLISON CREEK

088042603, Delaware, IA

Built 2003 Load: 26.2 t ADT: 44

LOCAL

Fair

Over: SMALL

090E12405, Dubuque, IA

Built 1979 Load: 26.2 t ADT: 60

930 140TH ST

Fair

Over: WEST OTTER CREEK DD 26

094251501, Hancock, IA

Built 1975 Load: 26.2 t ADT: 21

SB I-29

Fair

Over: DRAINAGE DITCH

1.6 Mi. N of Jct. SR F-20, Harrison, IA

Built 1966 Load: 26.2 t ADT: 7,250

LOCAL

Fair

Over: SMALL CREEK

086E10906, Jackson, IA

Built 1992 Load: 26.2 t ADT: 78

FM 120TH ST

Fair

Over: HOOSIER CREEK

081060509, Johnson, IA

Built 1900 Load: 26.2 t ADT: 1,500

TROY MILLS RD

Fair

Over: WAPSIPINICON RIVER

086070522, Linn, IA

Built 1951 Load: 26.2 t ADT: 2,033

FM

Fair

Over: SMALL STREAM

076182206, Marion, IA

Built 1960 Load: 26.2 t ADT: 3,550

IA 175

Fair

Over: DRAINAGE DITCH

3.0 mi. E of S.R. L12, Monona, IA

Built 1964 Load: 26.2 t ADT: 2,120

LOCAL ROAD

Fair

Over: WALNUT CREEK

072390103, Montgomery, IA

Built 1930 Load: 26.2 t ADT: 15

LOCAL RD

Fair

Over: WEST TARKIO CREEK

068392701, Page, IA

Built 1978 Load: 26.2 t ADT: 40

HICKORY ROAD

Fair

Over: STREAM

075391301, Pottawattamie, IA

Built 1950 Load: 26.2 t ADT: 29

LOCAL

Fair

Over: STREAM

079161801, Poweshiek, IA

Built 1953 Load: 26.2 t ADT: 34

FM

Fair

Over: W NISHNABOTNA RIVER

081370202, Shelby, IA

Built 1957 Load: 26.2 t ADT: 71

LOCAL

Fair

Over: COON CREEK

085142403, Tama, IA

Built 1945 Load: 26.2 t ADT: 20

LOCAL

Fair

Over: SILVER CREEK

100093603, Winneshiek, IA

Built 1939 Load: 26.2 t ADT: 97

LOCAL RD

Fair

Over: MIDDLE RIVER

076302001, Adair, IA

Built 1979 Load: 26.3 t ADT: 30

FM

Fair

Over: LONG BRANCH CREEK

067160904, Appanoose, IA

Built 1970 Load: 26.3 t ADT: 25

LOCAL

Fair

Over: STREAM

068193201, Appanoose, IA

Built 1979 Load: 26.3 t ADT: 5

WAGNER RD

Fair

Over: NO NAME CREEK

CITY BRIDGE NO. 44, Black Hawk, IA

Built 1986 Load: 26.3 t ADT: 1,820

12TH ST SE

Fair

Over: CREEK

.58 mile S of Central Ave, Bremer, IA

Built 1968 Load: 26.3 t ADT: 320

USHER AVE

Fair

Over: CREEK

093110902, Bremer, IA

Built 1994 Load: 26.3 t ADT: 20

GARDEN AVE

Fair

Over: HORTON CREEK

093130702, Bremer, IA

Built 1996 Load: 26.3 t ADT: 29

LOCAL

Fair

Over: SMALL STREAM

090170402, Butler, IA

Built 1900 Load: 26.3 t ADT: 15

FM

Fair

Over: LAKE CREEK

087333401, Calhoun, IA

Built 1967 Load: 26.3 t ADT: 20

FM - 610TH

Fair

Over: WATERWAY

075362902, Cass, IA

Built 1969 Load: 26.3 t ADT: 15

ECHO AVE

Fair

Over: NICHOLSON CREEK

080041104, Cedar, IA

Built 1960 Load: 26.3 t ADT: 11

135TH ST.

Fair

Over: DEEP CR

083E51903, Clinton, IA

Built 1974 Load: 26.3 t ADT: 21

LOCAL

Fair

Over: TRIB SOAP CR

070141605, Davis, IA

Built 1940 Load: 26.3 t ADT: 71

FM 270 AVE

Fair

Over: SMALL STREAM

089041302, Delaware, IA

Built 1970 Load: 26.3 t ADT: 275

FM

Fair

Over: LITTLE SIOUX RIVER

098373404, Dickinson, IA

Built 1974 Load: 26.3 t ADT: 51

FM 190TH ST

Fair

Over: BUFFALO CREEK

092211201, Franklin, IA

Built 1965 Load: 26.3 t ADT: 884

FM

Fair

Over: BRANCH BEAR CREEK

086180602, Grundy, IA

Built 1967 Load: 26.3 t ADT: 520

FM

Fair

Over: SKUNK RIVER

088243601, Hamilton, IA

Built 1962 Load: 26.3 t ADT: 270

FM

Fair

Over: STREAM

077182102, Marion, IA

Built 1962 Load: 26.3 t ADT: 90

FM

Fair

Over: SMALL STREAM

077191703, Marion, IA

Built 1962 Load: 26.3 t ADT: 60

450TH

Fair

Over: SMALL STREAM

099161201, Mitchell, IA

Built 1974 Load: 26.3 t ADT: 33

FM

Fair

Over: STREAM

071180608, Monroe, IA

Built 1962 Load: 26.3 t ADT: 60

FM

Fair

Over: WALNUT CREEK

073383101, Montgomery, IA

Built 1967 Load: 26.3 t ADT: 199

FM

Fair

Over: OCHEYEDAN RIVER

099403602, Osceola, IA

Built 1969 Load: 26.3 t ADT: 578

FM

Fair

Over: PERRY CREEK

090472704, Plymouth, IA

Built 1970 Load: 26.3 t ADT: 2,134

290TH STREET

Fair

Over: SILVER CREEK

074421204, Pottawattamie, IA

Built 1964 Load: 26.3 t ADT: 757

380TH STREET

Fair

Over: SILVER CREEK

076402102, Pottawattamie, IA

Built 1969 Load: 26.3 t ADT: 319

MULBERRY LANE

Fair

Over: STREAM

076422106, Pottawattamie, IA

Built 2001 Load: 26.3 t ADT: 27

Showing 4,501-4,550 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.