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

Poor

Over: PINE CREEK

078013401, Muscatine, IA

Built 1941 Load: 99.9 t ADT: 51

GARFIELD AVE

Poor

Over: SMALL

097462502, Sioux, IA

Built 1977 Load: 99.9 t ADT: 900

D54 DANBURY

Poor

Over: CREEK

086432301, Woodbury, IA

Built 1959 Load: 99.9 t ADT: 319

FM

Poor

Over: CREEK

087432305, Woodbury, IA

Built 1963 Load: 99.9 t ADT: 270

TRENTON AVE

Structurally Deficient

Over: STREAM

074302902, Adair, IA

Built 1945 ADT: 15

LOCAL

Structurally Deficient

Over: NODAWAY RIVER

074333239, Adair, IA

Built 1946 ADT: 45

LOCAL

Structurally Deficient

Over: STREAM

076312203, Adair, IA

Built 1900 ADT: 46

220TH STREET

Structurally Deficient

Over: KEMP CREEK

071350103, Adams, IA

Built 1910 ADT: 20

FIG AVENUE

Structurally Deficient

Over: KEMP CREEK

071350104, Adams, IA

Built 1927 ADT: 29

270TH STREET

Structurally Deficient

Over: LONG BRANCH

071353403, Adams, IA

Built 1960 ADT: 5

160TH STREET

Structurally Deficient

Over: STREAM

072320601, Adams, IA

Built 1956 ADT: 20

TULIP AVENUE

Structurally Deficient

Over: EAST NODAWAY RIVER

072320902, Adams, IA

Built 1976 ADT: 26

TULIP AVENUE

Structurally Deficient

Over: STREAM

072321704, Adams, IA

Built 1960 ADT: 26

REDWOOD AVENUE

Structurally Deficient

Over: STREAM

072323102, Adams, IA

Built 1968 ADT: 15

190TH STREET

Structurally Deficient

Over: EAST NODAWAY RIVER

072331303, Adams, IA

Built 1977 ADT: 34

MULBERRY AVE

Structurally Deficient

Over: EAST NODAWAY RIVER

072333004, Adams, IA

Built 1900 ADT: 5

110TH STREET

Structurally Deficient

Over: MIDDLE NODAWAY RIVER

073330703, Adams, IA

Built 1920 ADT: 29

FM

Structurally Deficient

Over: INDIAN CREEK

067160402, Appanoose, IA

Built 1970 ADT: 50

FM

Structurally Deficient

Over: STREAM

067190601, Appanoose, IA

Built 1953 ADT: 50

LOCAL

Structurally Deficient

Over: COAL CREEK

068191004, Appanoose, IA

Built 1927 ADT: 21

LOCAL

Structurally Deficient

Over: STREAM

068192204, Appanoose, IA

Built 1950 ADT: 73

FM

Structurally Deficient

Over: N SHOAL CREEK

068192904, Appanoose, IA

Built 1971 ADT: 45

LOCAL

Structurally Deficient

Over: UNNAMED STREAM

069163504, Appanoose, IA

Built 1975 ADT: 15

LOCAL

Structurally Deficient

Over: WALNUT CREEK

069192502, Appanoose, IA

Built 1971 ADT: 51

FM

Structurally Deficient

Over: WALNUT CREEK

069193202, Appanoose, IA

Built 1925 ADT: 30

LOCAL

Structurally Deficient

Over: E NISHNABOTNA RIVER

080351401, Audubon, IA

Built 1924 ADT: 5

FM

Structurally Deficient

Over: CREEK

080361803, Audubon, IA

Built 1935 ADT: 21

LOCAL (LWC)

Structurally Deficient

Over: PRAIRIE CREEK

082110401, Benton, IA

Built 1980 ADT: 15

LOCAL

Structurally Deficient

Over: STREAM

084090503, Benton, IA

Built 1977 ADT: 30

LOCAL

Structurally Deficient

Over: OPOSSUM CK

084090702, Benton, IA

Built 1959 ADT: 11

LOCAL

Structurally Deficient

Over: OPPOSSUM CREEK

084101101, Benton, IA

Built 1960 ADT: 34

E. 13TH ST

Structurally Deficient

Over: MUD CK

085102200, Benton, IA

Built 1965 ADT: 60

LOCAL

Structurally Deficient

Over: PRAIRIE CK

086091801, Benton, IA

Built 1947 ADT: 15

LOCAL

Structurally Deficient

Over: SPRING CK

086113002, Benton, IA

Built 1971 ADT: 26

LOCAL

Structurally Deficient

Over: PRATT CK

086113601, Benton, IA

Built 1900 ADT: 50

E BENNINGTON RD

Structurally Deficient

Over: WAPSIPINICON RIVER

90-11-23-01, Black Hawk, IA

Built 1945 ADT: 33

WHEELER RD

Structurally Deficient

Over: CRANE CREEK

90-11-26-02-10, Black Hawk, IA

Built 1948 ADT: 49

HAMMOND AVE

Structurally Deficient

Over: SINK CREEK

CITY BRIDGE NO. 33, Black Hawk, IA

Built 1900 ADT: 373

FM

Structurally Deficient

Over: DES MOINES RIVER

084272705, Boone, IA

Built 1909 ADT: 80

LOCAL

Structurally Deficient

Over: TRIB DES MOINES RIVER

084273103, Boone, IA

Built 1900 ADT: 26

LOCAL

Structurally Deficient

Over: TRIB DES MOINES RIVER

085271404, Boone, IA

Built 1900 ADT: 20

236TH ST

Structurally Deficient

Over: BUCK CREEK

091111003, Bremer, IA

Built 1957 ADT: 15

180TH ST

Structurally Deficient

Over: CRANE CREEK

092121801, Bremer, IA

Built 1964 ADT: 49

LOCAL 305TH ST.

Structurally Deficient

Over: LIME CR

087101303, Buchanan, IA

Built 1910 ADT: 16

LOCAL 325TH ST

Structurally Deficient

Over: MUD CR

087102903, Buchanan, IA

Built 1953 ADT: 30

LOCAL

Structurally Deficient

Over: BOYER CREEK

090362801, Buena Vista, IA

Built 1978 ADT: 30

LOCAL

Structurally Deficient

Over: CREEK

090373101, Buena Vista, IA

Built 1969 ADT: 50

LOCAL

Structurally Deficient

Over: MAPLE RIVER

090381504, Buena Vista, IA

Built 1914 ADT: 15

FM

Structurally Deficient

Over: STREAM

091361901, Buena Vista, IA

Built 1973 ADT: 60

LOCAL

Structurally Deficient

Over: BR RACCOON RIVER

092351002, Buena Vista, IA

Built 1971 ADT: 20

Showing 19,351-19,400 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.