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: BEAR CREEK

080132302, Poweshiek, IA

Built 1946 Load: 14.0 t ADT: 140

LOCAL

Poor

Over: STREAM

089372801, Sac, IA

Built 1961 Load: 14.0 t ADT: 45

LOCAL

Poor

Over: STREAM

070221302, Wayne, IA

Built 1975 Load: 14.0 t ADT: 11

LOCAL

Poor

Over: STREAM

068171102, Appanoose, IA

Built 1954 Load: 14.1 t ADT: 35

LOCAL

Poor

Over: CREEK

090373002, Buena Vista, IA

Built 1972 Load: 14.1 t ADT: 15

FM

Poor

Over: E.CEDAR CR.

087313202, Calhoun, IA

Built 1938 Load: 14.1 t ADT: 20

LOCAL

Poor

Over: DD NO 83

088311801, Calhoun, IA

Built 1900 Load: 14.1 t ADT: 30

295 AVENUE

Poor

Over: SLIPPERY ELM HOLLOW

068421404, Fremont, IA

Built 1966 Load: 14.1 t ADT: 21

LOCAL

Poor

Over: STREAM

079320902, Guthrie, IA

Built 1959 Load: 14.1 t ADT: 20

LOCAL

Poor

Over: STREAM

080310901, Guthrie, IA

Built 1977 Load: 14.1 t ADT: 50

LOCAL

Poor

Over: TIPTON CREEK

087220401, Hardin, IA

Built 1985 Load: 14.1 t ADT: 20

LOC 335TH ST

Poor

Over: ALLEN CREEK

078443203, Harrison, IA

Built 1959 Load: 14.1 t ADT: 20

LOC 140TH AVE

Poor

Over: PURCELL CREEK

095281704, Kossuth, IA

Built 1980 Load: 14.1 t ADT: 81

FM

Poor

Over: JIM CREEK

077281802, Madison, IA

Built 1948 Load: 14.1 t ADT: 668

LOCAL

Poor

Over: DRAINAGE

077171604, Mahaska, IA

Built 1950 Load: 14.1 t ADT: 34

LOCAL

Poor

Over: LUTES CREEK

082170702, Marshall, IA

Built 1938 Load: 14.1 t ADT: 82

LOCAL

Poor

Over: MINERVA CR

084201801, Marshall, IA

Built 1945 Load: 14.1 t ADT: 5

LOCAL

Poor

Over: LITTLE ASHER CREEK

085183301, Marshall, IA

Built 1944 Load: 14.1 t ADT: 21

LCL-RIST AVE

Poor

Over: DRAINAGE

071433403, Mills, IA

Built 1961 Load: 14.1 t ADT: 15

LOCAL ROAD

Poor

Over: LOCAL STREAM

071383202, Montgomery, IA

Built 1985 Load: 14.1 t ADT: 20

200TH ST

Poor

Over: MINK CREEK

092462701, Plymouth, IA

Built 1953 Load: 14.1 t ADT: 34

LOCAL ROAD

Poor

Over: CAMP CREEK

078221403, Polk, IA

Built 1914 Load: 14.1 t ADT: 26

142ND ST

Poor

Over: BEAR CREEK

085232803, Story, IA

Built 1900 Load: 14.1 t ADT: 30

IRR LOCAL

Poor

Over: BRANCH OF RICHLAND CREEK

082152001, Tama, IA

Built 1941 Load: 14.1 t ADT: 29

FM

Poor

Over: WEST 102 RIVER

070341201, Taylor, IA

Built 1952 Load: 14.1 t ADT: 34

LOCAL ROAD

Poor

Over: CREEK

098073205, Winneshiek, IA

Built 1915 Load: 14.1 t ADT: 29

130TH ST

Poor

Over: DRAINAGE DITCH 107

093252001, Wright, IA

Built 1936 Load: 14.1 t ADT: 26

LOCAL

Poor

Over: STREAM

074333101, Adair, IA

Built 1954 Load: 14.2 t ADT: 15

N77 UNION AVE

Poor

Over: CIPRA BRANCH

072321002, Adams, IA

Built 1900 Load: 14.2 t ADT: 71

FM

Poor

Over: CREEK

080351001, Audubon, IA

Built 1946 Load: 14.2 t ADT: 34

LOCAL

Poor

Over: PICAYNE CREEK

083381101, Crawford, IA

Built 1960 Load: 14.2 t ADT: 15

FM

Poor

Over: SEVEN MILE CREEK

067271302, Decatur, IA

Built 1969 Load: 14.2 t ADT: 190

180 TH

Poor

Over: STREAM

084311401, Greene, IA

Built 1958 Load: 14.2 t ADT: 26

LOCAL

Poor

Over: FROST CREEK

080332601, Guthrie, IA

Built 1959 Load: 14.2 t ADT: 34

LOCAL ROAD

Poor

Over: TAFT CREEK

099432702, Lyon, IA

Built 1900 Load: 14.2 t ADT: 26

LOCAL ROAD

Poor

Over: SKUNK RIVER

081231001, Polk, IA

Built 1928 Load: 14.2 t ADT: 29

BIRCH AVENUE

Poor

Over: WILLIAMS CREEK

073350506, Adams, IA

Built 1963 Load: 14.3 t ADT: 5

LOCAL

Poor

Over: D.D. NO 20

087322701, Calhoun, IA

Built 1900 Load: 14.3 t ADT: 40

FM

Poor

Over: MILL CREEK

082021204, Cedar, IA

Built 1958 Load: 14.3 t ADT: 550

HICKORY AVE

Poor

Over: LYNN CREEK

072062905, Henry, IA

Built 1988 Load: 14.3 t ADT: 73

FM 20TH ST

Poor

Over: BR UPPER IOWA RIVER

100121601, Howard, IA

Built 1951 Load: 14.3 t ADT: 15

RAPID CK RD

Poor

Over: BR RAPID CR

080053103, Johnson, IA

Built 1950 Load: 14.3 t ADT: 490

FM 160TH ST

Poor

Over: HINE CREEK

094300101, Kossuth, IA

Built 1967 Load: 14.3 t ADT: 26

LOCAL

Poor

Over: SNIPE CREEK

082192801, Marshall, IA

Built 1917 Load: 14.3 t ADT: 35

FM

Poor

Over: DD

084452509, Monona, IA

Built 1959 Load: 14.3 t ADT: 597

QUARTZ AVE

Poor

Over: WILLOW CREEK

093441202, Plymouth, IA

Built 1946 Load: 14.3 t ADT: 60

LOCAL

Poor

Over: CROOKED CREEK

069302702, Ringgold, IA

Built 1950 Load: 14.3 t ADT: 11

LOCAL

Poor

Over: STREAM

089360901, Sac, IA

Built 1932 Load: 14.3 t ADT: 11

LOCAL

Poor

Over: EAST 102 RIVER

067341603, Taylor, IA

Built 1940 Load: 14.3 t ADT: 26

LOCAL

Poor

Over: EAST RIVER

070322602, Taylor, IA

Built 1985 Load: 14.3 t ADT: 15

Showing 17,151-17,200 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.