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

Fair

Over: SOUTH FORK IOWA RIVER

088212004, Hardin, IA

Built 1980 Load: 30.2 t ADT: 47

FM TOLEDO AVE

Fair

Over: MILL CREEK

081412206, Harrison, IA

Built 1977 Load: 30.2 t ADT: 139

LOCAL

Fair

Over: GRITTER CREEK

078123502, Iowa, IA

Built 1977 Load: 30.2 t ADT: 26

FM

Fair

Over: SMALL CREEK

084E11502, Jackson, IA

Built 1979 Load: 30.2 t ADT: 226

FM

Fair

Over: ROCK BRANCH CREEK

072080302, Jefferson, IA

Built 1974 Load: 30.2 t ADT: 360

LOC 150TH ST

Fair

Over: PRAIRIE CREEK

094270801, Kossuth, IA

Built 1972 Load: 30.2 t ADT: 30

FM 130TH ST

Fair

Over: PRAIRIE CREEK

094271901, Kossuth, IA

Built 1972 Load: 30.2 t ADT: 249

FM 190TH AVE

Fair

Over: PRAIRIE CREEK

094271902, Kossuth, IA

Built 1971 Load: 30.2 t ADT: 489

LOC 140TH ST

Fair

Over: LOTTS CREEK

094301601, Kossuth, IA

Built 1971 Load: 30.2 t ADT: 400

FM 250TH ST

Fair

Over: BLACK CAT CREEK

096292401, Kossuth, IA

Built 1979 Load: 30.2 t ADT: 210

IA 16

Fair

Over: LITTLE CEDAR CREEK

1.7 mi. E of Jct. SR W46, Lee, IA

Built 1966 Load: 30.2 t ADT: 830

FM

Fair

Over: INDIAN CREEK

075033103, Louisa, IA

Built 1977 Load: 30.2 t ADT: 80

LOCAL

Fair

Over: BURNETT CREEK

084170702, Marshall, IA

Built 1979 Load: 30.2 t ADT: 82

FM

Fair

Over: LINN CREEK

084193202, Marshall, IA

Built 1987 Load: 30.2 t ADT: 147

FM

Fair

Over: CREEK

071181605, Monroe, IA

Built 1975 Load: 30.2 t ADT: 50

FM

Fair

Over: BEE BR,TRIB TO CEDAR CR

072181001, Monroe, IA

Built 1983 Load: 30.2 t ADT: 80

FM

Fair

Over: TARKIO CREEK

072372801, Montgomery, IA

Built 1978 Load: 30.2 t ADT: 509

LOCAL

Fair

Over: MUD CREEK

078010104, Muscatine, IA

Built 1983 Load: 30.2 t ADT: 383

LOCAL

Fair

Over: STREAM

098393401, Osceola, IA

Built 1934 Load: 30.2 t ADT: 35

SB US 75

Fair

Over: DRY CREEK

3.4 mi. N of jct. SR C60, Plymouth, IA

Built 1948 Load: 30.2 t ADT: 7,000

FM K-49

Fair

Over: PLYMOUTH CR

091450302, Plymouth, IA

Built 1974 Load: 30.2 t ADT: 1,236

FM

Fair

Over: JOHN'S CREEK

092443601, Plymouth, IA

Built 1976 Load: 30.2 t ADT: 1,157

FM

Fair

Over: INDIAN CREEK

093481202, Plymouth, IA

Built 1971 Load: 30.2 t ADT: 219

LOCAL

Fair

Over: NO LIZARD CK DD #77

092321702, Pocahontas, IA

Built 1976 Load: 30.2 t ADT: 60

FM-440TH STREET

Fair

Over: GRAYBILL CREEK

075391604, Pottawattamie, IA

Built 1972 Load: 30.2 t ADT: 50

FM-DOGWOOD RD

Fair

Over: GRAYBILL CREEK

075393101, Pottawattamie, IA

Built 1982 Load: 30.2 t ADT: 71

ROSEWOOD ROAD

Fair

Over: STREAM

076380301, Pottawattamie, IA

Built 1942 Load: 30.2 t ADT: 5

JUNIPER ROAD

Fair

Over: GRAYBILL CREEK

076393401, Pottawattamie, IA

Built 1982 Load: 30.2 t ADT: 20

FM

Fair

Over: N ENGLISH RIVER

079141804, Poweshiek, IA

Built 1979 Load: 30.2 t ADT: 70

FM

Fair

Over: LOTTS CREEK

067291203, Ringgold, IA

Built 1973 Load: 30.2 t ADT: 270

650TH AVE

Fair

Over: EAST BR INDIAN CREEK

083223404, Story, IA

Built 1976 Load: 30.2 t ADT: 1,228

FM

Fair

Over: SUGAR CREEK

083160904, Tama, IA

Built 1984 Load: 30.2 t ADT: 157

IRR-FM

Fair

Over: RAVEN CREEK

083162605, Tama, IA

Built 1981 Load: 30.2 t ADT: 432

FM

Fair

Over: HONEY CREEK

068332104, Taylor, IA

Built 1976 Load: 30.2 t ADT: 29

LOCAL

Fair

Over: PLATTE RIVER

071310301, Union, IA

Built 1979 Load: 30.2 t ADT: 15

FM

Fair

Over: THREE MILE CREEK

073300408, Union, IA

Built 1985 Load: 30.2 t ADT: 60

LOCAL

Fair

Over: LITTLE FOX

068113402, Van Buren, IA

Built 1978 Load: 30.2 t ADT: 26

FM

Fair

Over: S. AVERY CREEK

073143104, Wapello, IA

Built 1975 Load: 30.2 t ADT: 670

FM

Fair

Over: S AVERY CREEK

072151007, Wapello, IA

Built 1975 Load: 30.2 t ADT: 50

FM

Fair

Over: WINNEBAGO RIVER

098242301, Winnebago, IA

Built 1974 Load: 30.2 t ADT: 330

LOCAL

Fair

Over: BIG WHISKEY

088461801, Woodbury, IA

Built 1978 Load: 30.2 t ADT: 40

LOCAL

Fair

Over: ELLIOTT CREEK

088462201, Woodbury, IA

Built 1979 Load: 30.2 t ADT: 71

LOCAL

Fair

Over: ELLIOTT CREEK

088462803, Woodbury, IA

Built 1979 Load: 30.2 t ADT: 40

LOCAL

Fair

Over: BR PATTERSON CREEK

099063208, Allamakee, IA

Built 1915 Load: 30.3 t ADT: 29

LOCAL

Fair

Over: BRANCH MUD CREEK

083102702, Benton, IA

Built 1984 Load: 30.3 t ADT: 11

FM 260TH AVE

Fair

Over: OVERFLOW LITTLE SIOUX

094360202, Clay, IA

Built 1966 Load: 30.3 t ADT: 71

210TH AVENUE

Fair

Over: DRAINAGE DITCH 5

080E20104, Clinton, IA

Built 1965 Load: 30.3 t ADT: 750

220TH STREET

Fair

Over: BROPHY CREEK

081E50403, Clinton, IA

Built 1964 Load: 30.3 t ADT: 1,010

350TH AVE

Fair

Over: BROPHY CREEK

081E52002, Clinton, IA

Built 1964 Load: 30.3 t ADT: 460

190TH STREET

Fair

Over: DRAINAGE DITCH 12

082E21901, Clinton, IA

Built 1967 Load: 30.3 t ADT: 320

Showing 5,551-5,600 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.