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: FOX CREEK

068160102, Appanoose, IA

Built 1948 Load: 23.3 t ADT: 51

FM

Poor

Over: ELKHORN CREEK (LITTLE)

079012803, Cedar, IA

Built 1915 Load: 23.3 t ADT: 35

LOCAL

Poor

Over: LITTLE WAPSIPINICON RVR

096132003, Chickasaw, IA

Built 1975 Load: 23.3 t ADT: 49

LOCAL ROAD

Poor

Over: BRANCH BLACK HAWK CREEK

087153502, Grundy, IA

Built 1973 Load: 23.3 t ADT: 44

LOCAL

Poor

Over: SOUTH RACCOON RIVER

081332904, Guthrie, IA

Built 1994 Load: 23.3 t ADT: 11

LOCAL

Poor

Over: DD

089223101, Hardin, IA

Built 1925 Load: 23.3 t ADT: 41

LOCAL

Poor

Over: STREAM

077123402, Keokuk, IA

Built 1971 Load: 23.3 t ADT: 30

FM

Poor

Over: STREAM

074100704, Keokuk, IA

Built 1982 Load: 23.3 t ADT: 100

PALISADES ACCESS

Poor

Over: FLAMINGO CREEK

082063406, Linn, IA

Built 1971 Load: 23.3 t ADT: 40

LOCAL

Poor

Over: CEDAR CREEK

077143601, Mahaska, IA

Built 1951 Load: 23.3 t ADT: 20

LOCAL

Poor

Over: RAVEN CREEK

082172401, Marshall, IA

Built 1934 Load: 23.3 t ADT: 30

FM

Poor

Over: WILLOW CREEK

082422203, Monona, IA

Built 1979 Load: 23.3 t ADT: 199

140TH ST

Poor

Over: BROKEN KETTLE CREEK

093472801, Plymouth, IA

Built 1948 Load: 23.3 t ADT: 20

FM

Poor

Over: S RIVER

076220903, Warren, IA

Built 1966 Load: 23.3 t ADT: 50

LOCAL ROAD

Poor

Over: WEST FORK CROOKED CREEK

076092801, Washington, IA

Built 1949 Load: 23.3 t ADT: 26

LOCAL

Poor

Over: STREAM

093363405, Buena Vista, IA

Built 1900 Load: 23.4 t ADT: 11

LOCAL

Poor

Over: STREAM

084203001, Marshall, IA

Built 1981 Load: 23.4 t ADT: 11

LOCAL RD

Poor

Over: SMALL

099093102, Winneshiek, IA

Built 1978 Load: 23.4 t ADT: 26

LOCAL

Poor

Over: STREAM

069162302, Appanoose, IA

Built 1967 Load: 23.5 t ADT: 21

LOCAL

Poor

Over: SMALL

070193001, Appanoose, IA

Built 1983 Load: 23.5 t ADT: 26

LOCAL

Poor

Over: ELKHORN CREEK

078360604, Audubon, IA

Built 1973 Load: 23.5 t ADT: 62

LOCAL

Poor

Over: LITTLE BEAVER CREEK

082271901, Boone, IA

Built 1915 Load: 23.5 t ADT: 40

FM

Poor

Over: CREEK

082333315, Carroll, IA

Built 1939 Load: 23.5 t ADT: 399

LOCAL - YANKTON

Poor

Over: WATERWAY

074343101, Cass, IA

Built 1951 Load: 23.5 t ADT: 46

7TH AVE

Poor

Over: INDIAN CREEK

000000000, Pottawattamie, IA

Built 1930 Load: 23.5 t ADT: 235

FM

Poor

Over: STREAM

081151302, Poweshiek, IA

Built 1984 Load: 23.5 t ADT: 10

LOCAL

Poor

Over: BEAR CREEK

081153102, Poweshiek, IA

Built 1972 Load: 23.5 t ADT: 26

LOCAL

Poor

Over: CREEK

086420202, Woodbury, IA

Built 1947 Load: 23.5 t ADT: 26

230 TH

Poor

Over: STREAM

083310701, Greene, IA

Built 1957 Load: 23.6 t ADT: 46

FARM DRIVE

Poor

Over: BUTTRICKS CREEK

085302302, Greene, IA

Built 1900 Load: 23.6 t ADT: 10

LOCAL 162ND ST

Poor

Over: BR LITTLE WAPSIPINICON R

098142503, Howard, IA

Built 1986 Load: 23.6 t ADT: 50

DIAMOND AVE

Poor

Over: WESTFIELD CREEK

092480302, Plymouth, IA

Built 1900 Load: 23.6 t ADT: 11

FM

Poor

Over: BUCK CREEK

078161202, Poweshiek, IA

Built 1984 Load: 23.6 t ADT: 80

LOCAL

Poor

Over: BUCK CREEK

079162201, Poweshiek, IA

Built 1974 Load: 23.6 t ADT: 30

310TH ST

Poor

Over: DRAINAGE

082212001, Story, IA

Built 1951 Load: 23.6 t ADT: 90

LOCAL

Poor

Over: FELTERS BRANCH

076241805, Warren, IA

Built 1953 Load: 23.6 t ADT: 30

LOCAL 460TH ST

Poor

Over: BEAR CREEK

093412701, Cherokee, IA

Built 1916 Load: 23.7 t ADT: 45

FM

Poor

Over: OVER IAIS RR

078272003, Dallas, IA

Built 1940 Load: 23.7 t ADT: 150

COUNTY ROAD

Poor

Over: BRANCH MOSQUITO CREEK

079290803, Dallas, IA

Built 1926 Load: 23.7 t ADT: 21

HIGHWAY F-70 W

Poor

Over: CAMP CREEK

078213101, Jasper, IA

Built 1965 Load: 23.7 t ADT: 540

LOCAL

Poor

Over: BR LINN CR

084193001, Marshall, IA

Built 1942 Load: 23.7 t ADT: 30

FM

Poor

Over: DD #77 NO LIZARD CK

093333501, Pocahontas, IA

Built 1967 Load: 23.7 t ADT: 100

FM

Poor

Over: SMALL STREAM

078370701, Shelby, IA

Built 1960 Load: 23.7 t ADT: 240

LOCAL

Poor

Over: THREE MILE CREEK

073301004, Union, IA

Built 1978 Load: 23.7 t ADT: 35

LOCAL 440TH ST

Poor

Over: CREEK

093401401, Cherokee, IA

Built 1923 Load: 23.8 t ADT: 26

LOCAL

Poor

Over: ROCK CREEK

081180102, Jasper, IA

Built 1967 Load: 23.8 t ADT: 26

LOCAL

Poor

Over: DRAINAGE

075262809, Madison, IA

Built 1952 Load: 23.8 t ADT: 15

LOCAL

Poor

Over: OLIVE BRANCH CREEK

074140208, Mahaska, IA

Built 1956 Load: 23.8 t ADT: 80

LOCAL

Poor

Over: PILOT CREEK

093330201, Pocahontas, IA

Built 1976 Load: 23.8 t ADT: 30

LOCAL

Poor

Over: STREAM

088431004, Woodbury, IA

Built 1979 Load: 23.8 t ADT: 15

Showing 18,401-18,450 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.