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

N 41

Fair

Over: RACCOON RIVER

085331710, Carroll, IA

Built 1925 Load: 22.9 t ADT: 1,146

LOCAL G AVE.

Fair

Over: WILLOW CREEK

091410602, Cherokee, IA

Built 1985 Load: 22.9 t ADT: 40

IVANHOE AVE

Fair

Over: E WAPSIPINICON RIVER

96130302, Chickasaw, IA

Built 2016 Load: 22.9 t ADT: 41

LOCAL

Fair

Over: STREAM

081333102, Guthrie, IA

Built 1945 Load: 22.9 t ADT: 29

LOCAL

Fair

Over: CREEK

091291902, Humboldt, IA

Built 1900 Load: 22.9 t ADT: 11

FM

Fair

Over: BUFFALO CREEK

088393202, Ida, IA

Built 1969 Load: 22.9 t ADT: 589

US 30 & 151

Fair

Over: DRAINAGE DITCH

0.3 mi. E of Jct. I-380, Linn, IA

Built 1975 Load: 22.9 t ADT: 22,500

FM

Fair

Over: CREEK

083172601, Marshall, IA

Built 1962 Load: 22.9 t ADT: 39

IA 4

Fair

Over: DRAINAGE DITCH #41

5.5 mi S of jct US 18, Palo Alto, IA

Built 2000 Load: 22.9 t ADT: 2,040

US 65

Fair

Over: DRAINAGE DITCH

4.5 MILES N OF JCT SR S14, Polk, IA

Built 1978 Load: 22.9 t ADT: 9,600

IA 60 NB

Fair

Over: FLOYD RIVER TRIBUTARY

0.5 mi. S of SR K64, Sioux, IA

Built 1932 Load: 22.9 t ADT: 3,200

LOCAL

Fair

Over: SMALL STREAM

094463002, Sioux, IA

Built 1938 Load: 22.9 t ADT: 15

LOCAL

Fair

Over: MIDDLE 102 RIVER

069340302, Taylor, IA

Built 1979 Load: 22.9 t ADT: 15

FM

Fair

Over: PAINT CREEK

099071104, Winneshiek, IA

Built 1941 Load: 22.9 t ADT: 98

LOCAL

Fair

Over: WOLF CREEK

088441201, Woodbury, IA

Built 1935 Load: 22.9 t ADT: 5

LOCAL RD

Fair

Over: BR YELLOW RIVER

096042704, Allamakee, IA

Built 1977 Load: 23.0 t ADT: 49

FM

Fair

Over: PAINT CREEK

097033107, Allamakee, IA

Built 1957 Load: 23.0 t ADT: 137

FM

Fair

Over: FRENCH CREEK

099050205, Allamakee, IA

Built 1958 Load: 23.0 t ADT: 79

IA 188

Fair

Over: STREAM

1.7 mi. W of Jct. US 218, Butler, IA

Built 1900 Load: 23.0 t ADT: 490

LOCAL

Fair

Over: WILLOW CREEK

083330202, Carroll, IA

Built 1975 Load: 23.0 t ADT: 15

420TH ST

Fair

Over: ELK CREEK

095352001, Clay, IA

Built 1978 Load: 23.0 t ADT: 11

LOC SHERWOOD RD

Fair

Over: SMALL STREAM

088030802, Delaware, IA

Built 1970 Load: 23.0 t ADT: 49

YALE AVE

Fair

Over: KEG CREEK

078411302, Harrison, IA

Built 1940 Load: 23.0 t ADT: 29

LOCAL

Fair

Over: SMALL CREEK

084E22604, Jackson, IA

Built 1982 Load: 23.0 t ADT: 108

LOCAL RD

Fair

Over: STREAM

084E23101, Jackson, IA

Built 1980 Load: 23.0 t ADT: 11

W 92ND ST S

Fair

Over: SMALL STREAM

079200802, Jasper, IA

Built 1995 Load: 23.0 t ADT: 73

148TH ST.

Fair

Over: SMALL CREEK

085023003, Jones, IA

Built 1973 Load: 23.0 t ADT: 51

190TH AVE.

Fair

Over: STREAM

085030602, Jones, IA

Built 1974 Load: 23.0 t ADT: 11

LOCAL ROAD

Fair

Over: RAT CREEK

098432402, Lyon, IA

Built 1900 Load: 23.0 t ADT: 50

FM

Fair

Over: FIELD DRAINAGE DITCH

074263603, Madison, IA

Built 1949 Load: 23.0 t ADT: 259

LOCAL

Fair

Over: BALLINGER CREEK

077173608, Mahaska, IA

Built 1955 Load: 23.0 t ADT: 15

BROAD AVE

Fair

Over: SMALL STREAM

071370408, Montgomery, IA

Built 1949 Load: 23.0 t ADT: 699

US 75

Fair

Over: STREAM

0.1 mi S of Jct. SR C80, Plymouth, IA

Built 1999 Load: 23.0 t ADT: 18,200

FM

Fair

Over: MUCHIKINOCK CREEK

079230901, Polk, IA

Built 1969 Load: 23.0 t ADT: 2,998

LOCAL

Fair

Over: CREEK

095462202, Sioux, IA

Built 1962 Load: 23.0 t ADT: 45

LOCAL

Fair

Over: SMALL STREAM

095462801, Sioux, IA

Built 1962 Load: 23.0 t ADT: 40

FM

Fair

Over: DAVIS CREEK

076070102, Washington, IA

Built 1953 Load: 23.0 t ADT: 520

LOCAL

Fair

Over: ELLIOT CREEK

089450202, Woodbury, IA

Built 2003 Load: 23.0 t ADT: 30

LOCAL

Fair

Over: D D 67

088343502, Calhoun, IA

Built 1971 Load: 23.1 t ADT: 11

LOCAL

Fair

Over: FIELD STREAM

083362201, Carroll, IA

Built 1900 Load: 23.1 t ADT: 11

LOCAL

Fair

Over: FIELD STREAM

085351002, Carroll, IA

Built 1966 Load: 23.1 t ADT: 100

LOCAL

Fair

Over: CLEAR CREEK

082042204, Cedar, IA

Built 1939 Load: 23.1 t ADT: 80

FM

Fair

Over: DRAINAGE DITCH

070062401, Henry, IA

Built 1971 Load: 23.1 t ADT: 60

FM

Fair

Over: S ENGLISH RIVER

077140102, Mahaska, IA

Built 1952 Load: 23.1 t ADT: 25

LOCAL

Fair

Over: PLATTE BRANCH

068321004, Taylor, IA

Built 1967 Load: 23.1 t ADT: 15

FM

Fair

Over: GRAND RIVER

076313401, Adair, IA

Built 1950 Load: 23.2 t ADT: 34

LOCAL

Fair

Over: COOPER CREEK

068190704, Appanoose, IA

Built 2005 Load: 23.2 t ADT: 21

C33

Fair

Over: SHELL ROCK RIVER

092161301, Butler, IA

Built 1957 Load: 23.2 t ADT: 805

LOCAL

Fair

Over: FIELD STREAM

083352903, Carroll, IA

Built 1950 Load: 23.2 t ADT: 20

LOCAL - EAGLE

Fair

Over: BUCK CREEK

077360502, Cass, IA

Built 1997 Load: 23.2 t ADT: 62

Showing 3,601-3,650 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.