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: STREAM

091263009, Wright, IA

Built 1989 Load: 35.6 t ADT: 898

FM

Fair

Over: DD#34 RACCOON RIVER

092352201, Buena Vista, IA

Built 1983 Load: 35.7 t ADT: 549

LOCAL

Fair

Over: D D 92

089341802, Calhoun, IA

Built 1989 Load: 35.7 t ADT: 30

LOCAL - 570TH

Fair

Over: CAMP CREEK

077370302, Cass, IA

Built 1988 Load: 35.7 t ADT: 15

FM

Fair

Over: STREAM

073081206, Jefferson, IA

Built 1953 Load: 35.7 t ADT: 50

FM

Fair

Over: CHARITON RIVER

071231701, Lucas, IA

Built 1989 Load: 35.7 t ADT: 30

IA 5 (RELOC)

Fair

Over: OVER BNSF RR

0.3 MI. N OF JCT. US 34, Monroe, IA

Built 1995 Load: 35.7 t ADT: 9,400

IA 3

Fair

Over: MINK CREEK

0.4 mi W of SR K42, Plymouth, IA

Built 1954 Load: 35.7 t ADT: 1,420

230TH AVE

Fair

Over: BR LOST CREEK

079E41204, Scott, IA

Built 1992 Load: 35.7 t ADT: 370

D-25

Fair

Over: ABANDONED RR

088470906, Woodbury, IA

Built 1978 Load: 35.7 t ADT: 2,633

247TH AVE

Fair

Over: BARBER CREEK

081E33306, Clinton, IA

Built 1985 Load: 35.8 t ADT: 41

110TH ST.

Fair

Over: CREEK

083E31101, Clinton, IA

Built 1921 Load: 35.8 t ADT: 51

148TH ST.

Fair

Over: SMALL STREAM

083E32803, Clinton, IA

Built 1968 Load: 35.8 t ADT: 11

LOC 350TH ST

Fair

Over: NORTH BUFFALO CREEK

098273301, Kossuth, IA

Built 1990 Load: 35.8 t ADT: 15

33RD AVE

Fair

Over: CRANDIC RR

000000000, Linn, IA

Built 2006 Load: 35.8 t ADT: 10,700

ANSBOROUGH AVE

Fair

Over: TRIB TO MILLER CREEK

87-13-33-02-10, Black Hawk, IA

Built 1988 Load: 35.9 t ADT: 15

IA 4 & 175

Fair

Over: PURGATORY CREEK

2.8 mi. S of N jct IA 175, Calhoun, IA

Built 1973 Load: 35.9 t ADT: 1,410

US 30

Fair

Over: YANKEE RUN

2.4 mi. W of Jct. SR Y14, Cedar, IA

Built 1955 Load: 35.9 t ADT: 2,790

250TH AVE

Fair

Over: PRAIRIE CREEK

096362702, Clay, IA

Built 1990 Load: 35.9 t ADT: 62

ASPEN RD

Fair

Over: WILLOW CREEK

092060507, Clayton, IA

Built 1914 Load: 35.9 t ADT: 275

330 TH / E63

Fair

Over: WILLOW CREEK

082323201, Greene, IA

Built 1970 Load: 35.9 t ADT: 379

FM

Fair

Over: STREAM

086190518, Hardin, IA

Built 1997 Load: 35.9 t ADT: 59

FM

Fair

Over: CREEK

086191201, Hardin, IA

Built 1992 Load: 35.9 t ADT: 25

LOCAL

Fair

Over: DRAINAGE DITCH

086200603, Hardin, IA

Built 1994 Load: 35.9 t ADT: 16

EAST 156TH ST

Fair

Over: SMALL STREAM

080172404, Jasper, IA

Built 2000 Load: 35.9 t ADT: 131

FM

Fair

Over: N CEDAR CREEK

073190403, Monroe, IA

Built 1981 Load: 35.9 t ADT: 25

170TH ST

Fair

Over: CREEK

078E22101, Scott, IA

Built 1993 Load: 35.9 t ADT: 25

SB I-35

Fair

Over: OVER UP RR

1.4 MI. N OF JCT. US 30, Story, IA

Built 1966 Load: 35.9 t ADT: 18,000

SB US 218

Fair

Over: DAVIS CREEK

4.1 MI. S OF JCT. Ia. 22, Washington, IA

Built 1984 Load: 35.9 t ADT: 7,450

LOCAL ROAD

Fair

Over: CREEK

099100303, Winneshiek, IA

Built 1990 Load: 35.9 t ADT: 78

BRANDON RD

Fair

Over: CEDAR RIVER

87-11-19-04, Black Hawk, IA

Built 2012 Load: 36.0 t ADT: 1,542

7TH ST

Fair

Over: DRAINAGE DITCH

0.1 mi. S of Jct. SR C50, Black Hawk, IA

Built 1993 Load: 36.0 t ADT: 737

LOCAL

Fair

Over: BOYER CREEK

090362002, Buena Vista, IA

Built 1977 Load: 36.0 t ADT: 34

IA 141

Fair

Over: EAST NISHNABOTNA RIVER

0.3 MI. W OF W JCT. US 71, Carroll, IA

Built 1971 Load: 36.0 t ADT: 2,000

330TH AVE

Fair

Over: D.D#60

00000, Clay, IA

Built 2011 Load: 36.0 t ADT: 15

FM 290TH AVE

Fair

Over: PICKERAL RUN #37

097353202, Clay, IA

Built 1995 Load: 36.0 t ADT: 50

290TH ST

Fair

Over: LITTLE SIOUX RIVER

097371701, Clay, IA

Built 1978 Load: 36.0 t ADT: 30

GREAT RIVER RD

Fair

Over: BUCK CREEK

093023210, Clayton, IA

Built 1979 Load: 36.0 t ADT: 1,228

FM

Fair

Over: CREEK

067130503, Davis, IA

Built 1979 Load: 36.0 t ADT: 120

LOCAL 280 ST

Fair

Over: ROBINSON CREEK

087060601, Delaware, IA

Built 1981 Load: 36.0 t ADT: 33

FM - 175TH ST

Fair

Over: SMALL STREAM

089041105, Delaware, IA

Built 1955 Load: 36.0 t ADT: 59

LOC 110TH AVE

Fair

Over: STREAM

090060604, Delaware, IA

Built 1989 Load: 36.0 t ADT: 39

HWY 382

Fair

Over: SMALL NATURAL STREAM

081062303, Johnson, IA

Built 1958 Load: 36.0 t ADT: 3,810

FM SW WAPELLO A

Fair

Over: BR PRAIRIE CR

077052202, Johnson, IA

Built 1977 Load: 36.0 t ADT: 1,110

S.E.WAPELLO AVE

Fair

Over: RICHEY CREEK

077052502, Johnson, IA

Built 1994 Load: 36.0 t ADT: 20

FM SE SIOUX AVE

Fair

Over: STREAM

077053004, Johnson, IA

Built 1969 Load: 36.0 t ADT: 110

FM

Fair

Over: BUCK CREEK

078052803, Johnson, IA

Built 1991 Load: 36.0 t ADT: 30

480TH ST

Fair

Over: SMALL

078061201, Johnson, IA

Built 1978 Load: 36.0 t ADT: 81

SW 480TH ST

Fair

Over: STREAM

078070803, Johnson, IA

Built 1970 Load: 36.0 t ADT: 20

SW KANSAS AVE

Fair

Over: STREAM

078072302, Johnson, IA

Built 1993 Load: 36.0 t ADT: 40

Showing 7,651-7,700 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.