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

LOCAL

Fair

Over: COAL CREEK

076220103, Warren, IA

Built 1966 Load: 19.5 t ADT: 20

IA 141

Fair

Over: W BRANCH LITTLE SIOUX

0.8 mi E of SR K64, Woodbury, IA

Built 1959 Load: 19.5 t ADT: 1,490

LOCAL 250TH ST

Fair

Over: SMALL CREEK

088082103, Buchanan, IA

Built 1957 Load: 19.6 t ADT: 91

PINE CREEK AVE

Fair

Over: SMALL STREAM

088082108, Buchanan, IA

Built 1957 Load: 19.6 t ADT: 118

LOCAL 265TH ST

Fair

Over: SPRING CREEK

088102903, Buchanan, IA

Built 1959 Load: 19.6 t ADT: 20

LOC HARRISON AV

Fair

Over: SMALL STREAM

090090502, Buchanan, IA

Built 1959 Load: 19.6 t ADT: 73

BACKBONE ST PK

Fair

Over: STREAM

IN BACKBONE STATE PARK, Delaware, IA

Built 1934 Load: 19.6 t

N 6TH ST

Fair

Over: MEAD CREEK

097140108, Howard, IA

Built 1974 Load: 19.6 t ADT: 50

LOC 450TH ST

Fair

Over: UNION SLOUGH DITCH

099281101, Kossuth, IA

Built 1972 Load: 19.6 t ADT: 62

LOCAL

Fair

Over: BR OF CHARITON RIVER

071233102, Lucas, IA

Built 1960 Load: 19.6 t ADT: 15

35TH AVE

Fair

Over: MUD CREEK

079E11004, Scott, IA

Built 1965 Load: 19.6 t ADT: 26

255TH ST

Fair

Over: CREEK

079E20603, Scott, IA

Built 1965 Load: 19.6 t ADT: 26

LOCAL

Fair

Over: SIX MILE CREEK

094470502, Sioux, IA

Built 1961 Load: 19.6 t ADT: 71

LOCAL

Fair

Over: SIX MILE CREEK

095472801, Sioux, IA

Built 1964 Load: 19.6 t ADT: 34

LOCAL

Fair

Over: RAVEN CREEK

082160504, Tama, IA

Built 1940 Load: 19.6 t ADT: 29

FM

Fair

Over: HONEY CREEK

069322301, Taylor, IA

Built 1910 Load: 19.6 t ADT: 11

LOCAL

Fair

Over: MIDDLE 102 RIVER

069342304, Taylor, IA

Built 1977 Load: 19.6 t ADT: 5

LOCAL ROAD

Fair

Over: HUMPAL CREEK

097090201, Winneshiek, IA

Built 1900 Load: 19.6 t ADT: 78

LOCAL

Fair

Over: EAGLE CREEK

090251903, Wright, IA

Built 1976 Load: 19.6 t ADT: 15

110TH ST

Fair

Over: PLUM CREEK

093121001, Bremer, IA

Built 1997 Load: 19.7 t ADT: 26

IVY AVE

Fair

Over: SMALL STREAM

091130404, Bremer, IA

Built 1950 Load: 19.7 t ADT: 69

FM

Fair

Over: BLACK HAWK CREEK

088171901, Grundy, IA

Built 1900 Load: 19.7 t ADT: 354

LOCAL

Fair

Over: SKUNK RIVER

087243606, Hamilton, IA

Built 1952 Load: 19.7 t ADT: 100

LOCAL

Fair

Over: CREEK

093290702, Humboldt, IA

Built 1966 Load: 19.7 t ADT: 15

FM

Fair

Over: DRAINAGE WAY

078120601, Iowa, IA

Built 1945 Load: 19.7 t ADT: 10

LOCAL

Fair

Over: STREAM

099392001, Osceola, IA

Built 1941 Load: 19.7 t ADT: 50

680TH AVE

Fair

Over: DYE CREEK

083221204, Story, IA

Built 1900 Load: 19.7 t ADT: 26

LOCAL

Fair

Over: YELLOW RIVER BRANCH

096071403, Winneshiek, IA

Built 1975 Load: 19.7 t ADT: 39

LOCAL

Fair

Over: SHANGHAR CREEK

074321201, Adair, IA

Built 1940 Load: 19.8 t ADT: 21

LOCAL

Fair

Over: PENNY SPRINGS

096050903, Allamakee, IA

Built 1985 Load: 19.8 t ADT: 26

DONAHUE RD

Fair

Over: PAINT CREEK

A00170400, Allamakee, IA

Built 1900 Load: 19.8 t ADT: 10

LOCAL

Fair

Over: BLUFF CREEK

085271701, Boone, IA

Built 1900 Load: 19.8 t ADT: 30

330TH ST

Fair

Over: DRY CREEK

087073301, Buchanan, IA

Built 2007 Load: 19.8 t ADT: 62

DANIAL AVE

Fair

Over: SPRING CR

088102102, Buchanan, IA

Built 1956 Load: 19.8 t ADT: 11

130TH

Fair

Over: E BR BEAVER DAM CREEK

094202101, Cerro Gordo, IA

Built 1953 Load: 19.8 t ADT: 49

320TH

Fair

Over: CREEK

097201601, Cerro Gordo, IA

Built 1955 Load: 19.8 t ADT: 59

FM- 650TH ST

Fair

Over: STRATTON CREEK

090413203, Cherokee, IA

Built 1967 Load: 19.8 t ADT: 180

EAST MAIN ST.

Fair

Over: STRATTON CREEK

0904131, Cherokee, IA

Built 1967 Load: 19.8 t ADT: 173

110TH STREET

Fair

Over: SMALL

097132501, Chickasaw, IA

Built 1969 Load: 19.8 t ADT: 295

LOCAL

Fair

Over: EAST SOLDIER RIVER

084412704, Crawford, IA

Built 2008 Load: 19.8 t ADT: 15

310TH ST

Fair

Over: PORTER CREEK

085380301, Crawford, IA

Built 1940 Load: 19.8 t ADT: 5

FM

Fair

Over: MIDDLE CHEQUEST CREEK

070133504, Davis, IA

Built 1956 Load: 19.8 t ADT: 60

J AVE / P14

Fair

Over: RACCOON RIVER

083310304, Greene, IA

Built 1952 Load: 19.8 t ADT: 199

LOCAL

Fair

Over: CREEK

089223204, Hardin, IA

Built 1987 Load: 19.8 t ADT: 30

W 52ND ST S

Fair

Over: WARREN GROVE CREEK

079193102, Jasper, IA

Built 1933 Load: 19.8 t ADT: 21

LOCAL

Fair

Over: BENJAMIN CREEK

080192101, Jasper, IA

Built 1997 Load: 19.8 t ADT: 41

100TH AVE.

Fair

Over: LITTLE BEAR CREEK

084021002, Jones, IA

Built 2006 Load: 19.8 t ADT: 35

US 34

Fair

Over: TARKIO RIVER

0.7 mi. W of jct. SR M-63, Montgomery, IA

Built 1964 Load: 19.8 t ADT: 3,990

FM

Fair

Over: DEEP CREEK

094423201, O'Brien, IA

Built 1934 Load: 19.8 t ADT: 15

REDWING AVE

Fair

Over: FLOYD RIVER

097410302, O'Brien, IA

Built 2005 Load: 19.8 t ADT: 21

Showing 2,501-2,550 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.