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: S SOAP CREEK

070152905, Davis, IA

Built 1957 Load: 11.4 t ADT: 30

CANYON RD

Fair

Over: PEASE CREEK

IN LEDGES STATE PARK, Boone, IA

Built 1933 Load: 11.5 t

LOCAL

Fair

Over: BEAVER CREEK

084282801, Boone, IA

Built 1930 Load: 11.6 t ADT: 30

CANYON RD

Fair

Over: PEASE CREEK

IN LEDGES STATE PARK, Boone, IA

Built 1933 Load: 11.6 t

220TH ST

Fair

Over: ALLEN CREEK

079440301, Harrison, IA

Built 1940 Load: 11.6 t ADT: 11

MIAMA LAKE WMA

Fair

Over: LAKE MIAMI

073171703, Monroe, IA

Built 1900 Load: 11.6 t ADT: 5

LOCAL

Fair

Over: WOLF CREEK

073122004, Wapello, IA

Built 1995 Load: 11.6 t ADT: 16

LOCAL

Fair

Over: BUSH BRANCH

075301304, Adair, IA

Built 1915 Load: 11.7 t ADT: 11

LOCAL

Fair

Over: STREAM

075332508, Adair, IA

Built 1949 Load: 11.7 t ADT: 11

BUCK CREEK RD

Fair

Over: BUCK CREEK

093032205, Clayton, IA

Built 1954 Load: 11.7 t ADT: 39

270TH ST

Fair

Over: SM STREAM

093053405, Clayton, IA

Built 1920 Load: 11.7 t ADT: 11

FM 230TH AVE

Fair

Over: BUCK CREEK

087041702, Delaware, IA

Built 1963 Load: 11.7 t ADT: 383

175 TH

Fair

Over: RACCOON RIVER

084320803, Greene, IA

Built 1942 Load: 11.7 t ADT: 29

LOCAL ROAD

Fair

Over: CREEK

099083206, Winneshiek, IA

Built 1976 Load: 11.7 t ADT: 39

PARKLAND AVE

Fair

Over: HARDIN CREEK

083301004, Greene, IA

Built 1979 Load: 11.8 t ADT: 60

LOCAL

Fair

Over: ELM CREEK

079382404, Shelby, IA

Built 1926 Load: 11.8 t ADT: 62

LOCAL

Fair

Over: W NISHNABOTNA RIVER

802238, Shelby, IA

Built 1920 Load: 11.8 t ADT: 26

320TH ST

Fair

Over: SKUNK RIVER

082232703, Story, IA

Built 1949 Load: 11.8 t ADT: 80

100TH ST

Fair

Over: LONG DICK CREEK

085230301, Story, IA

Built 1956 Load: 11.8 t ADT: 45

270TH STREET

Fair

Over: TODD BRANCH

071323501, Adams, IA

Built 1961 Load: 11.9 t ADT: 5

190TH STREET

Fair

Over: STREAM

072322001, Adams, IA

Built 1962 Load: 11.9 t ADT: 26

190TH STREET

Fair

Over: STREAM

072322101, Adams, IA

Built 1962 Load: 11.9 t ADT: 20

180TH STREET

Fair

Over: STREAM

072331701, Adams, IA

Built 1961 Load: 11.9 t ADT: 15

FM-110TH STREET

Fair

Over: WILLIAMS CREEK

073351201, Adams, IA

Built 1979 Load: 11.9 t ADT: 29

325 AVENUE

Fair

Over: DEER CREEK

070410904, Fremont, IA

Built 2015 Load: 11.9 t ADT: 5

VEGA RD

Fair

Over: SMALL STREAM

081050304, Johnson, IA

Built 1985 Load: 11.9 t ADT: 45

FM

Fair

Over: PAINT CREEK

097051207, Allamakee, IA

Built 2002 Load: 12.0 t ADT: 69

LOCAL

Fair

Over: BRUSHY FORK CREEK

082342604, Carroll, IA

Built 1951 Load: 12.0 t ADT: 15

HOSCH RD

Fair

Over: CREEK

090023004, Dubuque, IA

Built 1926 Load: 12.0 t ADT: 34

FM - 335TH ST

Fair

Over: MOSQUITO CREEK

078413203, Harrison, IA

Built 1920 Load: 12.0 t ADT: 120

LOCAL

Fair

Over: LOTTS CREEK

067290101, Ringgold, IA

Built 1963 Load: 12.0 t ADT: 15

LOCAL ROAD

Fair

Over: HUMPAL CREEK

097090202, Winneshiek, IA

Built 1964 Load: 12.0 t ADT: 70

LOCAL

Fair

Over: MIDDLE RIVER

076300702, Adair, IA

Built 1915 Load: 12.1 t ADT: 5

LOCAL

Fair

Over: TROUBLESOME CREEK

078351305, Audubon, IA

Built 1959 Load: 12.1 t ADT: 21

LOCAL

Fair

Over: CREEK

096081903, Winneshiek, IA

Built 1965 Load: 12.1 t ADT: 59

YORK AVE

Fair

Over: NORTH RIVER

077303602, Adair, IA

Built 1915 Load: 12.2 t ADT: 35

OAK AVENUE

Fair

Over: STREAM

073330406, Adams, IA

Built 1930 Load: 12.2 t ADT: 40

FM

Fair

Over: EAST GRAND CREEK

080202304, Jasper, IA

Built 1953 Load: 12.2 t ADT: 15

LOCAL

Fair

Over: NORTH FORK CLANTON CREEK

074271606, Madison, IA

Built 1983 Load: 12.2 t ADT: 11

LOCAL

Fair

Over: SOUTH WHITE BREAST CREEK

071250902, Clarke, IA

Built 1985 Load: 12.3 t ADT: 15

LOCAL

Fair

Over: SMALL STREAM

085413502, Crawford, IA

Built 1900 Load: 12.3 t ADT: 21

FM - 335TH ST

Fair

Over: SMALL STREAM

078413601, Harrison, IA

Built 1952 Load: 12.3 t ADT: 40

LOCAL

Fair

Over: SMALL STREAM

079373401, Shelby, IA

Built 1963 Load: 12.3 t ADT: 46

FM

Fair

Over: BEAVER CREEK

083282101, Boone, IA

Built 1926 Load: 12.4 t ADT: 20

LOCAL

Fair

Over: INDIAN CREEK

067262005, Decatur, IA

Built 1905 Load: 12.4 t ADT: 5

LOCAL RD

Fair

Over: DRAINAGE

076261703, Madison, IA

Built 1978 Load: 12.4 t ADT: 20

LOCAL

Fair

Over: STREAM

086360711, Sac, IA

Built 1957 Load: 12.4 t ADT: 60

FM

Fair

Over: BASS CREEK

090290907, Webster, IA

Built 1979 Load: 12.4 t ADT: 150

LOCAL - 650TH

Fair

Over: W NODAWAY RIVER

074363604, Cass, IA

Built 1973 Load: 12.5 t ADT: 50

LOCAL

Fair

Over: N WYACONDAH RIVER

068131504, Davis, IA

Built 1940 Load: 12.5 t ADT: 50

Showing 1,201-1,250 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.