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: VILLAGE CREEK

098041408, Allamakee, IA

Built 1974 Load: 28.8 t ADT: 108

FM

Fair

Over: CREEK

078340301, Audubon, IA

Built 1945 Load: 28.8 t ADT: 45

IA 187

Fair

Over: LAMONT CREEK

0.2 mi. N of N Jct SR C64, Buchanan, IA

Built 1977 Load: 28.8 t ADT: 2,250

JACKSON AVE

Fair

Over: SMALL STREAM

088090904, Buchanan, IA

Built 1976 Load: 28.8 t ADT: 3,103

FM

Fair

Over: SMALL STREAM

090182502, Butler, IA

Built 1949 Load: 28.8 t ADT: 452

EUREKA AVE

Fair

Over: SMALL

079042602, Cedar, IA

Built 1979 Load: 28.8 t ADT: 20

IA 141

Fair

Over: DRAINAGE DITCH

1.9 mi. W of W jct SR L51, Crawford, IA

Built 1977 Load: 28.8 t ADT: 1,490

FM

Fair

Over: NORTH CHEQUEST CREEK

069121204, Davis, IA

Built 1986 Load: 28.8 t ADT: 40

OAK RD

Fair

Over: STREAM

090041603, Delaware, IA

Built 1978 Load: 28.8 t ADT: 59

LOC IVY RD

Fair

Over: BR LITTLE YORK

090050903, Delaware, IA

Built 1951 Load: 28.8 t ADT: 34

LOCAL

Fair

Over: BEAVER CREEK

078310504, Guthrie, IA

Built 1944 Load: 28.8 t ADT: 11

EB I-80

Fair

Over: CIC RAILWAY

3.0 mi. E of jct. I-380, Johnson, IA

Built 1963 Load: 28.8 t ADT: 30,600

FM

Fair

Over: SNYDER CR

079052901, Johnson, IA

Built 1977 Load: 28.8 t ADT: 130

FM

Fair

Over: SKUNK RIVER

069040706, Lee, IA

Built 1984 Load: 28.8 t ADT: 750

FM

Fair

Over: LITTLE ROCK RIVER

099430302, Lyon, IA

Built 1975 Load: 28.8 t ADT: 100

LOCAL

Fair

Over: DRAINAGE

075291204, Madison, IA

Built 1953 Load: 28.8 t ADT: 60

LOCAL

Fair

Over: ENGLISH CREEK

075193004, Marion, IA

Built 1986 Load: 28.8 t ADT: 82

LOCAL

Fair

Over: NORTH SKUNK RIVER

082202502, Marshall, IA

Built 1985 Load: 28.8 t ADT: 25

LCL-APPLEWOOD

Fair

Over: SILVER CREEK

073410601, Mills, IA

Built 1971 Load: 28.8 t ADT: 50

IA 2

Fair

Over: EAST NODAWAY RIVER

0.3 MI W OF SR N-14, Page, IA

Built 1975 Load: 28.8 t ADT: 2,680

LOCAL

Fair

Over: E TARKIO RIVER

070370203, Page, IA

Built 1991 Load: 28.8 t ADT: 5

FM

Fair

Over: SMALL STREAM

079240351, Polk, IA

Built 1972 Load: 28.8 t ADT: 5,178

350TH AVE

Fair

Over: STREAM

081143601, Poweshiek, IA

Built 1953 Load: 28.8 t ADT: 50

LOCAL

Fair

Over: PLATTE RIVER

070313401, Ringgold, IA

Built 1969 Load: 28.8 t ADT: 26

SB US 61

Fair

Over: DME RR

0.8 MI. N OF JCT I-80, Scott, IA

Built 1981 Load: 28.8 t ADT: 16,000

US 59

Fair

Over: DRAINAGE DITCH

2.6 MI. N OF Jct. I-80, Shelby, IA

Built 1970 Load: 28.8 t ADT: 4,850

FM

Fair

Over: PIGEON CREEK

801640, Shelby, IA

Built 1959 Load: 28.8 t ADT: 89

LOCAL

Fair

Over: OVER ABAND RR

094470802, Sioux, IA

Built 1963 Load: 28.8 t ADT: 34

SB I-35

Fair

Over: BEAR CREEK

3.3 MILES S OF JCT SR E18, Story, IA

Built 1967 Load: 28.8 t ADT: 15,250

150TH ST

Fair

Over: BEAR CREEK

085233205, Story, IA

Built 1985 Load: 28.8 t ADT: 50

LOCAL

Fair

Over: NORTH COON CREEK

085141104, Tama, IA

Built 1937 Load: 28.8 t ADT: 88

US 65

Fair

Over: OTTER CREEK

1.6 MI. S OF JCT. SR G-58, Warren, IA

Built 1958 Load: 28.8 t ADT: 2,380

IA 22

Fair

Over: DRAINAGE DITCH

0.5 MI. W OF JCT. IA 1, Washington, IA

Built 1994 Load: 28.8 t ADT: 3,330

A6W RIVER RD

Fair

Over: DRAINAGE

098081311, Winneshiek, IA

Built 1985 Load: 28.8 t ADT: 1,856

US 30 EB

Fair

Over: UP RR

5.8 MI. E OF S JCT. US 61, Clinton, IA

Built 1974 Load: 28.9 t ADT: 4,700

COUNTY ROAD

Fair

Over: BRANCH BEAVER CREEK

080260402, Dallas, IA

Built 1920 Load: 28.9 t ADT: 46

LOCAL

Fair

Over: CREEK

098372502, Dickinson, IA

Built 1973 Load: 28.9 t ADT: 60

LOCAL

Fair

Over: SMALL

097152201, Floyd, IA

Built 1989 Load: 28.9 t ADT: 20

LOCAL RD

Fair

Over: LOCAL DRAINAGE

072381801, Montgomery, IA

Built 1961 Load: 28.9 t ADT: 35

US 59

Fair

Over: JIM CREEK

3.5 MI. S OF JCT. IA 83, Pottawattamie, IA

Built 1986 Load: 28.9 t ADT: 1,490

LOCAL

Fair

Over: STREAM

077330801, Adair, IA

Built 1993 Load: 29.0 t ADT: 51

130TH STREET

Fair

Over: STREAM

073342203, Adams, IA

Built 1965 Load: 29.0 t ADT: 34

US 218

Fair

Over: STREAM

0.5 mi. S of Jct. SR D35, Black Hawk, IA

Built 1952 Load: 29.0 t ADT: 3,480

MARQUIS RD

Fair

Over: SHELL ROCK RIV OVERFLOW

90-14-04-07-20, Black Hawk, IA

Built 1992 Load: 29.0 t ADT: 207

ALLEY-6TH ST SW

Fair

Over: DRY RUN CREEK

ALLEY - S OF BREMER, Bremer, IA

Built 1986 Load: 29.0 t ADT: 599

GREAT RIVER RD

Fair

Over: BLUE BELL CREEK

091021303, Clayton, IA

Built 1983 Load: 29.0 t ADT: 403

118TH AVENUE

Fair

Over: WAPSIPINICON RIVER

082E11704, Clinton, IA

Built 1963 Load: 29.0 t ADT: 350

IA 2

Fair

Over: MCGRUDER CREEK

1.5 MI. E OF E JCT US 69, Decatur, IA

Built 1984 Load: 29.0 t ADT: 1,720

LOC STAGECOACH

Fair

Over: PRAIRIE CREEK

089062707, Delaware, IA

Built 1949 Load: 29.0 t ADT: 97

LOCAL

Fair

Over: HONEY CREEK

086210202, Hardin, IA

Built 1981 Load: 29.0 t ADT: 51

Showing 5,151-5,200 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.