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

S 96TH AVE W

Fair

Over: CALHOUN CREEK

078201801, Jasper, IA

Built 2004 Load: 47.8 t ADT: 60

IA 48

Fair

Over: RAMP CREEK

0.9 Mi. N oF Jct. SR M-56, Page, IA

Built 1987 Load: 47.8 t ADT: 1,780

FM

Fair

Over: BRANCH MIDDLE RIVER

075271904, Madison, IA

Built 1926 Load: 47.9 t ADT: 1,186

OLD IA 102

Fair

Over: MIDDLE CREEK

077162001, Mahaska, IA

Built 1962 Load: 47.9 t ADT: 1,550

NB US 218

Fair

Over: CEDAR RIVER

0.6 mi. N of Jct. SR C50, Bremer, IA

Built 1993 Load: 48.0 t ADT: 9,500

IA 57

Fair

Over: DRAINAGE DITCH

3.7 MI. W OF SR T-55, Butler, IA

Built 1929 Load: 48.0 t ADT: 2,220

LOCAL

Fair

Over: PERRY CREEK

091402905, Cherokee, IA

Built 2007 Load: 48.0 t ADT: 20

IA 2

Fair

Over: BRUSH CREEK

3.6 MI. W OF JCT. I-35, Decatur, IA

Built 1985 Load: 48.0 t ADT: 1,350

258TH ST

Fair

Over: SMALL STREAM

086E31304, Jackson, IA

Built 2011 Load: 48.0 t ADT: 15

FM

Fair

Over: JONES CREEK

075272805, Madison, IA

Built 1990 Load: 48.0 t ADT: 170

LOCAL

Fair

Over: MILL CREEK

096412601, O'Brien, IA

Built 1989 Load: 48.0 t ADT: 21

IA 10

Fair

Over: OVER UP RR

1.0 mi W of Ia. 60, Sioux, IA

Built 1983 Load: 48.0 t ADT: 4,260

NB I-380

Fair

Over: LIME CREEK

0.6 MI. N OF JCT. SR D48, Buchanan, IA

Built 1984 Load: 48.1 t ADT: 8,850

FM

Fair

Over: WEST ROCK CREEK

081030101, Cedar, IA

Built 1979 Load: 48.1 t ADT: 70

FM

Fair

Over: TIMBER CREEK

083171704, Marshall, IA

Built 1991 Load: 48.1 t ADT: 187

HICKORY AVE

Fair

Over: STREAM

098173204, Mitchell, IA

Built 1987 Load: 48.1 t ADT: 78

IA 191

Fair

Over: MOSQUITO CREEK

2.0 MI. S OF Jct. IA 37, Shelby, IA

Built 1991 Load: 48.1 t ADT: 790

DYSART RD

Fair

Over: TRIB TO MILLER CREEK

87-12-06-02-10, Black Hawk, IA

Built 1994 Load: 48.2 t ADT: 1,660

1ST AVENUE

Fair

Over: BIG ELKHORN CREEK

079013600, Cedar, IA

Built 1997 Load: 48.2 t ADT: 2,310

FM

Fair

Over: PIONEER CREEK

082030602, Cedar, IA

Built 1994 Load: 48.2 t ADT: 770

AGATE RD

Fair

Over: SAND CREEK

094062003, Clayton, IA

Built 2002 Load: 48.2 t ADT: 295

FM 160TH ST

Fair

Over: BEAR CREEK

089030203, Delaware, IA

Built 1994 Load: 48.2 t ADT: 462

FM

Fair

Over: STONY CREEK

098383401, Dickinson, IA

Built 1990 Load: 48.2 t ADT: 315

FM

Fair

Over: N. FORK LITTLE MAQUOKETA

090E11902, Dubuque, IA

Built 2001 Load: 48.2 t ADT: 240

FM

Fair

Over: OLD MANS CREEK

079100608, Iowa, IA

Built 1999 Load: 48.2 t ADT: 2,760

FM

Fair

Over: ALLOWAY CREEK

080180401, Jasper, IA

Built 1991 Load: 48.2 t ADT: 40

FM

Fair

Over: S COAL CREEK

074172003, Mahaska, IA

Built 1994 Load: 48.2 t ADT: 610

ALLENS GROVE RD

Fair

Over: BR MUD CREEK

080E23408, Scott, IA

Built 1993 Load: 48.2 t ADT: 130

10TH AVE

Fair

Over: N FORK BUFFALO CREEK

098260502, Winnebago, IA

Built 2001 Load: 48.2 t ADT: 279

235 TH / E53

Fair

Over: HARDIN CREEK

083301005, Greene, IA

Built 1993 Load: 48.3 t ADT: 1,047

BOYSON RD

Fair

Over: DRY CREEK

000000000, Linn, IA

Built 2000 Load: 48.3 t ADT: 14,100

FM

Fair

Over: WEST FORK DES MOINES R

097332705, Palo Alto, IA

Built 1983 Load: 48.3 t ADT: 71

FM

Fair

Over: BEAVER CREEK

090172008, Butler, IA

Built 1979 Load: 48.4 t ADT: 679

130TH AVE

Fair

Over: CREEK

080E32002, Scott, IA

Built 1929 Load: 48.4 t ADT: 45

19TH ST SW

Fair

Over: CHESLEA CREEK

000000000, Cerro Gordo, IA

Built 1931 Load: 48.6 t ADT: 9,148

FM

Fair

Over: SMALL CREEK

086E11104, Jackson, IA

Built 1950 Load: 48.6 t ADT: 500

US 169

Fair

Over: MIDDLE FORK GRAND RIVER

1.0 mi. N of Jct. SR P32, Ringgold, IA

Built 1989 Load: 48.6 t ADT: 370

US 63

Fair

Over: IOWA RIVER

1.3 mi N of SR E64, Tama, IA

Built 1978 Load: 48.6 t ADT: 3,390

FM

Fair

Over: BEAVER CREEK

082283409, Boone, IA

Built 1920 Load: 48.7 t ADT: 139

LANTERN AVE

Fair

Over: MILL CREEK

091031306, Clayton, IA

Built 1940 Load: 48.9 t ADT: 11

FIRST ST

Fair

Over: UP RR

Mt Vernon Road, Linn, IA

Built 1934 Load: 48.9 t ADT: 2,532

LOCAL

Fair

Over: SALT CREEK

084131802, Tama, IA

Built 1988 Load: 48.9 t ADT: 49

US 63

Fair

Over: UP RR

0.1 MILES N OF JCT IA 146, Mahaska, IA

Built 1985 Load: 49.0 t ADT: 2,130

LOCAL

Fair

Over: SMALL STREAM

094113601, Chickasaw, IA

Built 1977 Load: 49.1 t ADT: 73

LOCAL

Fair

Over: SMALL STREAM

080180203, Jasper, IA

Built 2003 Load: 49.1 t ADT: 16

IA 9

Fair

Over: STREAM

0.1 mi. E of S.R. K30, Lyon, IA

Built 1982 Load: 49.1 t ADT: 3,180

US 34

Fair

Over: WEST TARKIO CREEK

0.5 MI E OF E JCT. SR H34, Montgomery, IA

Built 1964 Load: 49.1 t ADT: 3,990

IVY AVE.

Fair

Over: COLDWATER CREEK

093170902, Butler, IA

Built 1977 Load: 49.2 t ADT: 62

LOCAL

Fair

Over: BR. WHITEBREAST

071251006, Clarke, IA

Built 1996 Load: 49.2 t ADT: 26

FM

Fair

Over: TRIB. TO BIG CREEK

081250901, Polk, IA

Built 1991 Load: 49.2 t ADT: 150

Showing 8,551-8,600 of 20,753 bridges

Related

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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.