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

FM

Fair

Over: SMALL STREAM

075070201, Washington, IA

Built 1966 Load: 70.3 t ADT: 3,370

LOCAL

Fair

Over: LITTLE CEDAR CREEK

070082302, Van Buren, IA

Built 2003 Load: 71.0 t ADT: 16

US 169

Fair

Over: CARRS CREEK

2.7 mi. N of Jct. SR H17, Madison, IA

Built 1974 Load: 72.2 t ADT: 1,230

400TH STREET

Fair

Over: STREAM

075401402, Pottawattamie, IA

Built 1979 Load: 72.5 t ADT: 50

MONUMENT ROAD

Fair

Over: STREAM

075441112, Pottawattamie, IA

Built 1977 Load: 72.5 t ADT: 417

LOCAL 290TH ST

Fair

Over: DRY CREEK

087070901, Buchanan, IA

Built 2003 Load: 72.6 t ADT: 5

FM 230 AVE

Fair

Over: SMALL STREAM

087040802, Delaware, IA

Built 1963 Load: 72.8 t ADT: 383

LOCAL

Fair

Over: CREEK

071250402, Clarke, IA

Built 1976 Load: 73.5 t ADT: 26

FM

Fair

Over: SMALL STREAM

076181712, Marion, IA

Built 1964 Load: 73.5 t ADT: 3,050

FM

Fair

Over: STREAM

084433004, Monona, IA

Built 1952 Load: 73.5 t ADT: 29

FM

Fair

Over: CREEK

086450302, Woodbury, IA

Built 1965 Load: 73.6 t ADT: 399

LOCAL (LWC)

Fair

Over: SMALL STREAM

086121204, Benton, IA

Built 1992 Load: 73.8 t ADT: 26

DUBUQUE ST

Fair

Over: IOWA RIVER

080063318, Johnson, IA

Built 1991 Load: 76.1 t ADT: 6,900

FM

Fair

Over: ALDRICH CREEK

087412804, Ida, IA

Built 1969 Load: 76.2 t ADT: 429

FM 255TH ST

Fair

Over: SMALL STREAM

088062405, Delaware, IA

Built 1959 Load: 78.0 t ADT: 344

FM

Fair

Over: CREEK

068090103, Van Buren, IA

Built 1985 Load: 78.1 t ADT: 430

LOCAL

Fair

Over: GOODWATER CREEK

070200804, Wayne, IA

Built 1988 Load: 78.9 t ADT: 15

FM

Fair

Over: STREAM

084433005, Monona, IA

Built 1956 Load: 79.0 t ADT: 40

FM

Fair

Over: SMALL CREEK

080301801, Guthrie, IA

Built 1958 Load: 79.2 t ADT: 170

US 34

Fair

Over: DRAINAGE DITCH

0.7 MI. W of Jct. SR L63, Mills, IA

Built 1964 Load: 82.4 t ADT: 4,260

IA 2

Fair

Over: GRAND RIVER

3.0 MI. W 0F JCT. I-35, Decatur, IA

Built 1985 Load: 83.4 t ADT: 1,350

US 34

Fair

Over: STREAM

2.7 MI. E OF JCT. IA 5, Monroe, IA

Built 1959 Load: 83.4 t ADT: 3,900

FM

Fair

Over: SMALL STREAM

077021303, Muscatine, IA

Built 1950 Load: 84.4 t ADT: 320

LOCAL

Fair

Over: STREAM

100420902, Osceola, IA

Built 1935 Load: 84.9 t ADT: 35

FM

Fair

Over: SMALL STREAM

082391601, Crawford, IA

Built 1962 Load: 86.0 t ADT: 349

I-80

Fair

Over: DRAINAGE DITCH

0.7 mi. W of Jct. SR Y26, Cedar, IA

Built 1960 Load: 88.3 t ADT: 35,400

LOCAL

Fair

Over: BR SALT CREEK

083123001, Benton, IA

Built 1997 Load: 88.6 t ADT: 30

LOCAL

Fair

Over: BR PRAIRIE CREEK

083120402, Benton, IA

Built 1997 Load: 88.6 t ADT: 20

US 59

Fair

Over: JENSEN CREEK

1.2 MI. S OF JCT. IA 44, Shelby, IA

Built 1968 Load: 88.6 t ADT: 4,580

50 TH DR

Fair

Over: BLUE CREEK

086090205, Benton, IA

Built 2000 Load: 88.7 t ADT: 11

E HARTFORD AVE

Fair

Over: CREEK

078241100, Polk, IA

Built 1980 Load: 88.9 t ADT: 5,181

FM

Fair

Over: STREAM

073171003, Monroe, IA

Built 1950 Load: 89.1 t ADT: 30

IA 21

Fair

Over: STREAM

3.1 MILES N OF JCT IA 85, Poweshiek, IA

Built 1962 Load: 89.1 t ADT: 1,730

LOCAL

Fair

Over: STREAM

74321560, Adair, IA

Built 2001 Load: 90.1 t ADT: 30

IA 48

Fair

Over: CLARKS BRANCH

1.9 MI. N OF SR H14, Cass, IA

Built 1974 Load: 90.5 t ADT: 1,090

IA 148

Fair

Over: STREAM

2.2 mi. S of Jct. SR G-61, Cass, IA

Built 1959 Load: 90.5 t ADT: 770

I-35 NB OFF RMP

Fair

Over: BEAVER DAM CREEK

0.1 MI. S OF Jct. SR B60, Cerro Gordo, IA

Built 1972 Load: 90.5 t ADT: 130

I 35 SB OFF RAMP

Fair

Over: BEAVER DAM CREEK

0.1 mi. N of Jct. SR B60, Cerro Gordo, IA

Built 1972 Load: 90.5 t ADT: 210

IA 44

Fair

Over: SIX MILE CREEK

0.9 MI. E OF JCT. US 30, Harrison, IA

Built 1978 Load: 90.5 t ADT: 800

110TH AVE

Fair

Over: HENRY CREEK

094380802, Clay, IA

Built 1965 Load: 95.9 t ADT: 26

LOCAL

Fair

Over: BR CLEAR CREEK

100052705, Allamakee, IA

Built 1978 Load: 97.2 t ADT: 15

250TH AVE

Fair

Over: LITTLE MUDDY CREEK

097361502, Clay, IA

Built 1996 Load: 97.2 t ADT: 72

FM 320TH ST

Fair

Over: DD #28

097363201, Clay, IA

Built 1996 Load: 97.2 t ADT: 1,228

YARD G ROAD

Fair

Over: LONG CREEK

APPROX. 5200 S. OF RD. I, Des Moines, IA

Built 1946 Load: 97.2 t ADT: 10

PLANT ROAD FS-12

Fair

Over: LONG CREEK

APPROX. 3000' N. OF RD I, Des Moines, IA

Built 2003 Load: 97.2 t ADT: 10

BUNKER HILL RD

Fair

Over: BEERS CREEK

084011105, Jones, IA

Built 2015 Load: 97.2 t ADT: 11

FM-M-66

Fair

Over: CREEK

080361704, Audubon, IA

Built 1972 Load: 99.9 t ADT: 338

FM

Fair

Over: CREEK

079361701, Audubon, IA

Built 1952 Load: 99.9 t ADT: 50

FM

Fair

Over: SMALL STREAM

083120201, Benton, IA

Built 1992 Load: 99.9 t ADT: 45

FM

Fair

Over: SMALL STREAM

084102001, Benton, IA

Built 1992 Load: 99.9 t ADT: 45

Showing 8,901-8,950 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.