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

IA 25

Fair

Over: STREAM

1.0 MI. N OF N JCT. US 34, Union, IA

Built 1976 Load: 24.9 t ADT: 4,870

LOCAL

Fair

Over: TRIB TO BIG INDIAN CREEK

068100806, Van Buren, IA

Built 1958 Load: 24.9 t ADT: 73

LOCAL

Fair

Over: SMALL STREAM

069092903, Van Buren, IA

Built 1971 Load: 24.9 t ADT: 47

FM

Fair

Over: WEST FORK CROOKED CREEK

074071303, Washington, IA

Built 1978 Load: 24.9 t ADT: 60

FM

Fair

Over: W. FORK CROOKED CREEK

076092702, Washington, IA

Built 1978 Load: 24.9 t ADT: 45

FM

Fair

Over: SMALL STREAM

070212007, Wayne, IA

Built 1965 Load: 24.9 t ADT: 280

LOCAL

Fair

Over: LIZARD CREEK

089300202, Webster, IA

Built 1967 Load: 24.9 t ADT: 35

IA 376

Fair

Over: FLOYD RIVER

1.3 mi. S of SR D12, Woodbury, IA

Built 1957 Load: 24.9 t ADT: 9,200

K64

Fair

Over: SIDE DITCH STREAM

At jct SR K64 & US 20, Woodbury, IA

Built 1959 Load: 24.9 t ADT: 10

LOCAL

Fair

Over: SMALL STREAM

087430304, Woodbury, IA

Built 2001 Load: 24.9 t ADT: 11

LOCAL

Fair

Over: STREAM

074320602, Adair, IA

Built 1950 Load: 25.0 t ADT: 51

LOCAL (LWC)

Fair

Over: PRAIRIE CREEK

083110701, Benton, IA

Built 1986 Load: 25.0 t ADT: 5

FM

Fair

Over: SMALL

085090403, Benton, IA

Built 1978 Load: 25.0 t ADT: 157

FM

Fair

Over: BIG ELKHORN CR

079012503, Cedar, IA

Built 2006 Load: 25.0 t ADT: 51

270TH ST

Fair

Over: BR W BR WAPSINONOC CR

080043201, Cedar, IA

Built 2010 Load: 25.0 t ADT: 11

LOCAL

Fair

Over: CREEK

094151601, Floyd, IA

Built 1958 Load: 25.0 t ADT: 49

FM

Fair

Over: IOWAY CREEK

086262502, Hamilton, IA

Built 1924 Load: 25.0 t ADT: 20

840 190TH ST

Fair

Over: BR.BOONE RIVER #8

095252001, Hancock, IA

Built 1980 Load: 25.0 t ADT: 26

730 170TH ST

Fair

Over: DD #8

095253101, Hancock, IA

Built 1983 Load: 25.0 t ADT: 15

780 170TH ST

Fair

Over: BR, BOONE RIVER #8

095253101, Hancock, IA

Built 1978 Load: 25.0 t ADT: 15

LOCAL

Fair

Over: BR E FORK CROOKED CREEK

073051404, Henry, IA

Built 1982 Load: 25.0 t ADT: 26

FM

Fair

Over: CEDAR CREEK

076131902, Keokuk, IA

Built 1930 Load: 25.0 t ADT: 40

MORGAN BR RD

Fair

Over: MORGAN CREEK

083082802, Linn, IA

Built 1987 Load: 25.0 t ADT: 34

IA 9

Fair

Over: OSTERMAN CREEK

3.4 mi. E of jct. US 59, Osceola, IA

Built 1978 Load: 25.0 t ADT: 2,020

FM

Fair

Over: CREEK

075303301, Adair, IA

Built 1932 Load: 25.1 t ADT: 50

W 12TH ST

Fair

Over: TRIB TO BEAVER CREEK

89-14-18-01-10, Black Hawk, IA

Built 1939 Load: 25.1 t ADT: 34

N BUTLER RD

Fair

Over: BEAVER CREEK

90-14-31-02-10, Black Hawk, IA

Built 1955 Load: 25.1 t ADT: 108

FM 252ND ST

Fair

Over: WAPSIPINICON RIVER

091112005, Bremer, IA

Built 1985 Load: 25.1 t ADT: 432

IOWA AVE

Fair

Over: SMALL STREAM

087092004, Buchanan, IA

Built 1957 Load: 25.1 t ADT: 35

LOC UNION AVE

Fair

Over: SMALL STREAM

090071602, Buchanan, IA

Built 1955 Load: 25.1 t ADT: 30

FM

Fair

Over: W BR BUFFALO CREEK

090082103, Buchanan, IA

Built 1957 Load: 25.1 t ADT: 118

FM

Fair

Over: BUFFALO CREEK

090082401, Buchanan, IA

Built 1955 Load: 25.1 t ADT: 167

LOC 110TH ST

Fair

Over: OTTER CR

090090901, Buchanan, IA

Built 1963 Load: 25.1 t ADT: 47

LOCAL 240TH ST

Fair

Over: BUFFALO CREEK

088071703, Buchanan, IA

Built 1986 Load: 25.1 t ADT: 73

LOCAL

Fair

Over: POWELL CREEK

091373204, Buena Vista, IA

Built 1977 Load: 25.1 t ADT: 50

LOCAL

Fair

Over: FIELD STREAM

084352310, Carroll, IA

Built 1971 Load: 25.1 t ADT: 459

300TH ST

Fair

Over: CROOKED CR

079020805, Cedar, IA

Built 2007 Load: 25.1 t ADT: 30

110TH STREET

Fair

Over: BRANCH OF PIONEER CREEK

082030901, Cedar, IA

Built 2003 Load: 25.1 t ADT: 34

340TH

Fair

Over: SPRING CREEK

097200401, Cerro Gordo, IA

Built 1985 Load: 25.1 t ADT: 47

NB I-35

Fair

Over: BAILEY CREEK

2.7 MI. N Jct. SR C13, Cerro Gordo, IA

Built 1971 Load: 25.1 t ADT: 8,650

FM

Fair

Over: ACKLEY CREEK

094171704, Floyd, IA

Built 1957 Load: 25.1 t ADT: 59

LOCAL

Fair

Over: SHELL ROCK RIVER

094172803, Floyd, IA

Built 1987 Load: 25.1 t ADT: 49

FM

Fair

Over: CEDAR RIVER

095153407, Floyd, IA

Built 1980 Load: 25.1 t ADT: 167

VINE AVENUE

Fair

Over: N BEAVER CREEK

090191502, Franklin, IA

Built 1958 Load: 25.1 t ADT: 25

LOCAL RAVEN AVE

Fair

Over: BEAVER CREEK

090203602, Franklin, IA

Built 1958 Load: 25.1 t ADT: 41

VIOLET AVE

Fair

Over: MAYNES CREEK

091191008, Franklin, IA

Built 1956 Load: 25.1 t ADT: 10

200TH STREET

Fair

Over: W FORK CEDAR RIVER

092190201, Franklin, IA

Built 1956 Load: 25.1 t ADT: 20

KILLDEER AVE

Fair

Over: BUFFALO CR

092211102, Franklin, IA

Built 1958 Load: 25.1 t ADT: 20

240TH STREET

Fair

Over: OTTER CREEK

093211301, Franklin, IA

Built 1957 Load: 25.1 t ADT: 30

240TH STREET

Fair

Over: OTTER CREEK

093211601, Franklin, IA

Built 1955 Load: 25.1 t ADT: 30

Showing 4,151-4,200 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.