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

LARK

Fair

Over: BAILEY CREEK

094213602, Cerro Gordo, IA

Built 1974 Load: 41.3 t ADT: 275

SB I-35

Fair

Over: CERRO GORDO COUNTY TRAIL

0.7 mi. N of jct. SR B65, Cerro Gordo, IA

Built 1972 Load: 41.3 t ADT: 8,850

FM 240TH AVE

Fair

Over: DRAINAGE DITCH #28

097363304, Clay, IA

Built 1987 Load: 41.3 t ADT: 1,228

SB I-35

Fair

Over: OVER ABAND RR

2.9 MI. S OF SR C47, Franklin, IA

Built 1974 Load: 41.3 t ADT: 8,250

WB COLL IA 100

Fair

Over: OVER CC RR & BIKE TRAIL

0.1 MI. N OF JCT. IA #100, Linn, IA

Built 1982 Load: 41.3 t ADT: 10,300

SB I-29

Fair

Over: HAYNIE SLOUGH

2.4 mi. S of S jct. US 34, Mills, IA

Built 1971 Load: 41.3 t ADT: 6,850

FM

Fair

Over: HONEY CREEK

069323101, Taylor, IA

Built 1998 Load: 41.3 t ADT: 26

THRUSH

Fair

Over: DEER CREEK

100191702, Worth, IA

Built 1972 Load: 41.3 t ADT: 393

LOCAL (LWC)

Fair

Over: PRAIRIE CREEK

082093002, Benton, IA

Built 1979 Load: 41.4 t ADT: 5

EB IA 2

Fair

Over: HORSE CREEK

1.0 MI. W OF I-29, Fremont, IA

Built 1969 Load: 41.4 t ADT: 4,000

LOCAL

Fair

Over: CREEK

080363003, Audubon, IA

Built 1925 Load: 41.5 t ADT: 30

LOCAL (LWC)

Fair

Over: SMALL STREAM

083113002, Benton, IA

Built 1992 Load: 41.5 t ADT: 15

CO RD

Fair

Over: DRAINAGE DITCH #31

088313501, Calhoun, IA

Built 1990 Load: 41.5 t ADT: 669

GARBER RD

Fair

Over: SOUTH CEDAR CREEK

000000000, Clayton, IA

Built 2009 Load: 41.5 t ADT: 638

LOCAL

Fair

Over: TRIB MAPLE RIVER

088401101, Ida, IA

Built 2002 Load: 41.5 t ADT: 26

URBANA RD

Fair

Over: WEST BLUE CREEK

085080607, Linn, IA

Built 1987 Load: 41.5 t ADT: 1,257

FM

Fair

Over: SMALL STREAM

075030603, Louisa, IA

Built 1960 Load: 41.5 t ADT: 560

FM

Fair

Over: STREAM

076150905, Mahaska, IA

Built 1962 Load: 41.5 t ADT: 370

IA 330

Fair

Over: CLEAR CREEK

1.8 MI. S OF S JCT SR S52, Marshall, IA

Built 1979 Load: 41.5 t ADT: 4,150

TREASURE LANE

Fair

Over: DRAINAGE

077441610, Pottawattamie, IA

Built 2012 Load: 41.5 t ADT: 11

250TH ST

Fair

Over: LOST CREEK

079E50701, Scott, IA

Built 1985 Load: 41.5 t ADT: 80

200TH ST

Fair

Over: DD 81

084222603, Story, IA

Built 2000 Load: 41.5 t ADT: 40

FM

Fair

Over: MIDDLE RIVER

077231505, Warren, IA

Built 1994 Load: 41.5 t ADT: 409

R 38/510TH AVE

Fair

Over: WALNUT CREEK

083242902, Story, IA

Built 2010 Load: 41.6 t ADT: 4,647

FM- 610TH ST

Fair

Over: MAPLE RIVER

090390801, Cherokee, IA

Built 1995 Load: 41.7 t ADT: 1,017

210 TH

Fair

Over: STREAM

084293601, Greene, IA

Built 1926 Load: 41.7 t ADT: 30

LOCAL

Fair

Over: CREEK

089402901, Ida, IA

Built 1999 Load: 41.7 t ADT: 30

FM

Fair

Over: TAFT CREEK

099432402, Lyon, IA

Built 1955 Load: 41.7 t ADT: 439

IA 31

Fair

Over: DRY CREEK

2.2 mi. S of jct SR D54, Woodbury, IA

Built 1988 Load: 41.7 t ADT: 850

THRUSH

Fair

Over: DRAINAGE DITCH

100192902, Worth, IA

Built 1971 Load: 41.7 t ADT: 393

LOCAL

Fair

Over: UPPER IOWA RIVER

099063007, Allamakee, IA

Built 1986 Load: 41.8 t ADT: 59

CORP.LINE RD

Fair

Over: BR WEST NISHNABOTA RIVER

082361701, Carroll, IA

Built 1980 Load: 41.8 t ADT: 289

LOCAL

Fair

Over: CREEK

085E32902, Jackson, IA

Built 2002 Load: 41.8 t ADT: 15

FM

Fair

Over: STOFFERAN CREEK

095420302, O'Brien, IA

Built 1976 Load: 41.8 t ADT: 1,277

FM

Fair

Over: WATERMAN CREEK

097400102, O'Brien, IA

Built 1977 Load: 41.8 t ADT: 309

FM

Fair

Over: SMALL

090482308, Plymouth, IA

Built 1900 Load: 41.8 t ADT: 628

IA 140

Fair

Over: MC ELHANEY CREEK

1.4 mi. N of US 20, Woodbury, IA

Built 1983 Load: 41.8 t ADT: 1,930

216TH AVE

Fair

Over: CREEK

086E33106, Jackson, IA

Built 2000 Load: 41.9 t ADT: 25

143RD ST

Fair

Over: SMALL STREAM

085E52405, Jackson, IA

Built 2000 Load: 41.9 t ADT: 60

BADGER AVE

Fair

Over: WATERWAY

091142906, Bremer, IA

Built 1992 Load: 42.0 t ADT: 97

FM - 570TH

Fair

Over: SPRING CREEK

076373402, Cass, IA

Built 1980 Load: 42.0 t ADT: 120

I 35 NB

Fair

Over: STREAM

1.8 MILES N OF SEC RD D20, Hamilton, IA

Built 1972 Load: 42.0 t ADT: 8,200

SB I-35

Fair

Over: STREAM

1.8 MILES N OF SEC RD D20, Hamilton, IA

Built 1972 Load: 42.0 t ADT: 8,200

LOCAL

Fair

Over: CREEK

085E52702, Jackson, IA

Built 1999 Load: 42.0 t ADT: 26

535 AVE

Fair

Over: CREEK

084E62804, Jackson, IA

Built 2001 Load: 42.0 t ADT: 11

IA 37

Fair

Over: MOSER CREEK

1.4 MI. W Jct. IA #191, Shelby, IA

Built 1961 Load: 42.0 t ADT: 630

HAMILTON AVE

Fair

Over: BEAR CR

087093004, Buchanan, IA

Built 2006 Load: 42.1 t ADT: 59

FM

Fair

Over: OTTER CREEK

089091907, Buchanan, IA

Built 2001 Load: 42.1 t ADT: 805

US 63

Fair

Over: E. FK WAPSIPINICON RIVER

2.1 MI. N OF JCT. US #18, Chickasaw, IA

Built 1962 Load: 42.1 t ADT: 4,200

FM

Fair

Over: IOWA RIVER

086192205, Hardin, IA

Built 1981 Load: 42.1 t ADT: 1,061

Showing 8,251-8,300 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.