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

180TH ST

Fair

Over: WESTFIELD CREEK

092481701, Plymouth, IA

Built 1900 Load: 14.0 t ADT: 11

FM

Fair

Over: STREAM

090171001, Butler, IA

Built 1973 Load: 14.1 t ADT: 49

FM RT M-36

Fair

Over: EAST BOYER RIVER

083391304, Crawford, IA

Built 1958 Load: 14.1 t ADT: 1,951

COUNTY ROAD

Fair

Over: BRANCH PANTHER CREEK

080283303, Dallas, IA

Built 1925 Load: 14.1 t ADT: 72

LOCAL

Fair

Over: E FORK DES MOINES RIVER

099313603, Emmet, IA

Built 1954 Load: 14.1 t ADT: 110

FM

Fair

Over: SOUTH BEAVER CREEK

078310703, Guthrie, IA

Built 1958 Load: 14.1 t ADT: 20

FM & 110TH ST

Fair

Over: WILLOW RIVER

081421601, Harrison, IA

Built 1918 Load: 14.1 t ADT: 29

LOCAL 110TH ST

Fair

Over: CRANE CREEK

099133301, Howard, IA

Built 1985 Load: 14.1 t ADT: 16

FM

Fair

Over: SMALL

081090901, Iowa, IA

Built 1945 Load: 14.1 t ADT: 180

LOCAL

Fair

Over: INDIAN CREEK

073223002, Lucas, IA

Built 1958 Load: 14.1 t ADT: 30

LANCER AVE

Fair

Over: BIG CEDAR RIVER

097170208, Mitchell, IA

Built 2002 Load: 14.1 t ADT: 1,905

FM

Fair

Over: STREAM

072162206, Monroe, IA

Built 1959 Load: 14.1 t ADT: 60

FM

Fair

Over: PORTER CREEK

086383501, Sac, IA

Built 1953 Load: 14.1 t ADT: 26

LOCAL

Fair

Over: BOYER CREEK

089371102, Sac, IA

Built 1958 Load: 14.1 t ADT: 34

FM

Fair

Over: SMALL STREAM

079380704, Shelby, IA

Built 1957 Load: 14.1 t ADT: 159

FM

Fair

Over: STREAM

071293401, Union, IA

Built 1960 Load: 14.1 t ADT: 45

FM

Fair

Over: WOLF CREEK

070220302, Wayne, IA

Built 1957 Load: 14.1 t ADT: 40

FM

Fair

Over: BRANCH YELLOW RIVER

096050907, Allamakee, IA

Built 1959 Load: 14.2 t ADT: 39

FM

Fair

Over: SOAP CREEK

070163105, Appanoose, IA

Built 1956 Load: 14.2 t ADT: 80

LOCALIOWA AVE

Fair

Over: BEAR CR

087092004, Buchanan, IA

Built 1953 Load: 14.2 t ADT: 35

LOCAL 310TH ST

Fair

Over: LIME CR

087102303, Buchanan, IA

Built 1957 Load: 14.2 t ADT: 59

FM

Fair

Over: EF DES MOINES RIVER

100322401, Emmet, IA

Built 1957 Load: 14.2 t ADT: 300

DOVE RD.

Fair

Over: OTTER CREEK

094072904, Fayette, IA

Built 1972 Load: 14.2 t ADT: 20

M AVE

Fair

Over: STREAM

084301902, Greene, IA

Built 1958 Load: 14.2 t ADT: 51

LOCAL

Fair

Over: STREAM

080332402, Guthrie, IA

Built 1959 Load: 14.2 t ADT: 34

202ND ST.

Fair

Over: FARM CREEK

086012803, Jones, IA

Built 1956 Load: 14.2 t ADT: 25

LOC 345TH ST

Fair

Over: MUD CREEK

098293605, Kossuth, IA

Built 1965 Load: 14.2 t ADT: 225

FM

Fair

Over: WEST NODAWAY TRIB

073363306, Montgomery, IA

Built 1961 Load: 14.2 t ADT: 11

LOCAL

Fair

Over: OTTER CREEK

099421001, Osceola, IA

Built 1938 Load: 14.2 t ADT: 21

255TH STREET

Fair

Over: LONG BRANCH

068382503, Page, IA

Built 1963 Load: 14.2 t ADT: 29

FM

Fair

Over: MUD CREEK

074412501, Pottawattamie, IA

Built 1958 Load: 14.2 t ADT: 45

LOCAL

Fair

Over: STREAM

079131701, Poweshiek, IA

Built 1977 Load: 14.2 t ADT: 5

FM

Fair

Over: PAINT CREEK

097033107, Allamakee, IA

Built 1957 Load: 14.3 t ADT: 137

FM

Fair

Over: WAPSIPINICON RIVER

095133301, Chickasaw, IA

Built 1947 Load: 14.3 t ADT: 98

FM

Fair

Over: SOUTH RIVER

073271506, Clarke, IA

Built 1955 Load: 14.3 t ADT: 71

KENNEDY RD

Fair

Over: STREAM

092031603, Clayton, IA

Built 1955 Load: 14.3 t ADT: 62

SPOOK CAVE RD

Fair

Over: SM STREAM

095041604, Clayton, IA

Built 1954 Load: 14.3 t ADT: 91

LOCAL

Fair

Over: BRITTON BRANCH

068261205, Decatur, IA

Built 2000 Load: 14.3 t ADT: 15

LOCAL OAK RD

Fair

Over: STREAM

090041603, Delaware, IA

Built 1965 Load: 14.3 t ADT: 59

LOCAL

Fair

Over: FLOOD CREEK

094170101, Floyd, IA

Built 1984 Load: 14.3 t ADT: 39

LOCAL RD

Fair

Over: NORTH RIVER

076261104, Madison, IA

Built 1920 Load: 14.3 t ADT: 60

LCL-DONNER AVE

Fair

Over: LOCAL CREEK

073412305, Mills, IA

Built 1920 Load: 14.3 t ADT: 29

LOCAL

Fair

Over: SOLDIER VALLEY D D

082433202, Monona, IA

Built 1900 Load: 14.3 t ADT: 5

LOCAL SEC RD

Fair

Over: WATERMAN CREEK

097391901, O'Brien, IA

Built 1955 Load: 14.3 t ADT: 35

LOCAL

Fair

Over: DRAINAGE

074381704, Pottawattamie, IA

Built 1996 Load: 14.3 t ADT: 15

LOCAL

Fair

Over: ELM CREEK

079370404, Shelby, IA

Built 2000 Load: 14.3 t ADT: 41

LOCAL

Fair

Over: ELM CREEK

079371702, Shelby, IA

Built 1969 Load: 14.3 t ADT: 46

370TH

Fair

Over: STREAM

098202201, Worth, IA

Built 1962 Load: 14.3 t ADT: 73

FM

Fair

Over: SMALL

069042306, Lee, IA

Built 1980 Load: 14.4 t ADT: 60

LCL-KEYS AVE

Fair

Over: RAINES BR

072412803, Mills, IA

Built 1914 Load: 14.4 t ADT: 15

Showing 1,351-1,400 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.