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: WATERWAY

076342201, Cass, IA

Built 1900 Load: 27.1 t ADT: 60

FM - 650TH ST

Fair

Over: BUFFALO CREEK

090423301, Cherokee, IA

Built 1973 Load: 27.1 t ADT: 350

LOCAL 420TH ST

Fair

Over: CREEK

093410601, Cherokee, IA

Built 1966 Load: 27.1 t ADT: 30

FM

Fair

Over: HICKEY CREEK

082381302, Crawford, IA

Built 1963 Load: 27.1 t ADT: 816

LOCAL

Fair

Over: MUDDY CREEK

098350401, Dickinson, IA

Built 1970 Load: 27.1 t ADT: 11

240TH STREET

Fair

Over: BEAVERDAM CREEK

093191801, Franklin, IA

Built 1980 Load: 27.1 t ADT: 26

100 TH

Fair

Over: BUTTRICKS CREEK

085300401, Greene, IA

Built 1977 Load: 27.1 t ADT: 15

FM & PANORA AVE

Fair

Over: WILLOW RIVER

081422905, Harrison, IA

Built 1972 Load: 27.1 t ADT: 100

LOCAL

Fair

Over: STREAM

079101702, Iowa, IA

Built 1976 Load: 27.1 t ADT: 80

FM

Fair

Over: LONG CREEK

074041604, Louisa, IA

Built 1977 Load: 27.1 t ADT: 45

LOCAL ROAD

Fair

Over: LITTLE ROCK RIVER

099433201, Lyon, IA

Built 1970 Load: 27.1 t ADT: 34

FM

Fair

Over: MIDDLE RIVER

075291306, Madison, IA

Built 1981 Load: 27.1 t ADT: 50

LOCAL

Fair

Over: HAITZ DD

085451201, Monona, IA

Built 1962 Load: 27.1 t ADT: 20

MALLARD AVE

Fair

Over: SMALL NATURAL STREAM

093452329, Plymouth, IA

Built 1974 Load: 27.1 t ADT: 5

FM

Fair

Over: JORDAN CREEK

074393003, Pottawattamie, IA

Built 1957 Load: 27.1 t ADT: 100

FM

Fair

Over: PLATTE RIVER

069310301, Ringgold, IA

Built 1969 Load: 27.1 t ADT: 379

US 18

Fair

Over: FLOYD RIVER

0.2 W of Jct. SR L26, Sioux, IA

Built 1992 Load: 27.1 t ADT: 5,100

FM

Fair

Over: DUCK VALLEY CREEK

070212305, Wayne, IA

Built 1965 Load: 27.1 t ADT: 280

FM

Fair

Over: LITTLE SIOUX RIVER

086430703, Woodbury, IA

Built 1966 Load: 27.1 t ADT: 319

LOCAL RD

Fair

Over: TEEPLE CREEK

097061302, Allamakee, IA

Built 1960 Load: 27.2 t ADT: 128

LOCAL

Fair

Over: VILLAGE CREEK

098052301, Allamakee, IA

Built 1965 Load: 27.2 t ADT: 44

FM F-65

Fair

Over: CROOKED CREEK

078343301, Audubon, IA

Built 1936 Load: 27.2 t ADT: 60

FM

Fair

Over: DD #65

088321802, Calhoun, IA

Built 1987 Load: 27.2 t ADT: 957

FM

Fair

Over: STORM CREEK

085343101, Carroll, IA

Built 1964 Load: 27.2 t ADT: 1,047

140TH ST

Fair

Over: BR YANKEE RUN

082022501, Cedar, IA

Built 2006 Load: 27.2 t ADT: 100

VIOLET ST

Fair

Over: ROCK FALLS CREEK

097190304, Cerro Gordo, IA

Built 1900 Load: 27.2 t ADT: 26

LOCAL

Fair

Over: CREEK

072271903, Clarke, IA

Built 1980 Load: 27.2 t ADT: 11

463RD AVENUE

Fair

Over: CREEK

082E71804, Clinton, IA

Built 1923 Load: 27.2 t ADT: 11

LOCAL CO.LINE

Fair

Over: SMALL STREAM

083E60103, Clinton, IA

Built 1993 Load: 27.2 t ADT: 78

LOC CANDLE RD

Fair

Over: PRAIRIE CREEK

089062805, Delaware, IA

Built 1950 Load: 27.2 t ADT: 59

EAST 16TH ST

Fair

Over: LAKE PEOSTA CHANNEL

000000000, Dubuque, IA

Built 1982 Load: 27.2 t ADT: 9,191

COUNTY RD X-40

Fair

Over: WALNUT CREEK

083031804, Jones, IA

Built 1960 Load: 27.2 t ADT: 770

220TH ST.

Fair

Over: BRANCH OF SILVER CREEK

086042001, Jones, IA

Built 1980 Load: 27.2 t ADT: 91

LOCAL(DEAD END)

Fair

Over: TRIB S FK ENGLISH RIVER

077121603, Keokuk, IA

Built 1996 Load: 27.2 t ADT: 11

LOCAL

Fair

Over: DRAINAGE

075270304, Madison, IA

Built 1959 Load: 27.2 t ADT: 29

US 169

Fair

Over: MIDDLE RIVER

2.2 MI. S OF S JCT. IA 92, Madison, IA

Built 1976 Load: 27.2 t ADT: 1,890

380TH

Fair

Over: LITTLE CEDAR RIVER

098161303, Mitchell, IA

Built 1979 Load: 27.2 t ADT: 44

430TH

Fair

Over: LITTLE CEDAR RIVER

099161503, Mitchell, IA

Built 1984 Load: 27.2 t ADT: 403

LOCAL

Fair

Over: MCCABDLESS CLEGHORN DD

085462302, Monona, IA

Built 2004 Load: 27.2 t ADT: 34

FM

Fair

Over: CREEK

073381402, Montgomery, IA

Built 1975 Load: 27.2 t ADT: 60

MAGNOLIA ROAD

Fair

Over: STREAM

076401903, Pottawattamie, IA

Built 1953 Load: 27.2 t ADT: 11

LOCAL

Fair

Over: STREAM

078140102, Poweshiek, IA

Built 1960 Load: 27.2 t ADT: 30

FM RD F16

Fair

Over: W FORK/W NISHNABOTNA

081380501, Shelby, IA

Built 1970 Load: 27.2 t ADT: 60

E 13TH ST

Fair

Over: SKUNK RIVER

083240103, Story, IA

Built 1968 Load: 27.2 t ADT: 13,164

710TH AVE

Fair

Over: HARDIN-STORY DD I

085210304, Story, IA

Built 1947 Load: 27.2 t ADT: 60

IA 28

Fair

Over: NORTH RIVER

0.6 MILES N OF SR G24, Warren, IA

Built 1983 Load: 27.2 t ADT: 5,900

FM

Fair

Over: NORTH FORK LONG CREEK

075060702, Washington, IA

Built 1969 Load: 27.2 t ADT: 100

375TH

Fair

Over: DRAINAGE DITCH

098211803, Worth, IA

Built 1940 Load: 27.2 t ADT: 11

SB I-35

Fair

Over: IOWA RIVER

4.0 mi. N of SR C 70, Wright, IA

Built 1974 Load: 27.2 t ADT: 8,250

E CEDAR-WAPSI RD

Fair

Over: WAPSIPINCON RIVER

90-11-10-03, Black Hawk, IA

Built 1969 Load: 27.3 t ADT: 1,493

Showing 4,801-4,850 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.