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

LAKE AVE

Good

Over: MINNIE BROOK

090450502, Plymouth, IA

Built 1998 Load: 45.5 t ADT: 50

280TH ST

Good

Over: DRAINAGE

090460201, Plymouth, IA

Built 1990 Load: 45.5 t ADT: 80

270TH ST

Good

Over: DEER CREEK

091433201, Plymouth, IA

Built 1997 Load: 45.5 t ADT: 15

SKILLET CREEK AVE

Good

Over: SKILLET CREEK

086271603, Webster, IA

Built 1999 Load: 45.5 t ADT: 50

LOCAL

Good

Over: SPRING CREEK

088290601, Webster, IA

Built 1996 Load: 45.5 t ADT: 72

FM

Good

Over: DEER CREEK

090290802, Webster, IA

Built 2008 Load: 45.5 t ADT: 20

LOCAL

Good

Over: YELLOW RIVER

096071006, Winneshiek, IA

Built 1998 Load: 45.5 t ADT: 39

LOCAL ROAD

Good

Over: CREEK

097081010, Winneshiek, IA

Built 2002 Load: 45.5 t ADT: 20

LOCAL

Good

Over: SMALL STREAM

098071305, Winneshiek, IA

Built 1998 Load: 45.5 t ADT: 33

LOCAL ROAD

Good

Over: CREEK

098072706, Winneshiek, IA

Built 2003 Load: 45.5 t ADT: 11

LOCAL ROAD

Good

Over: DRY RUN CREEK

098093302, Winneshiek, IA

Built 2005 Load: 45.5 t ADT: 20

LOCAL ROAD

Good

Over: CREEK

098102002, Winneshiek, IA

Built 2002 Load: 45.5 t ADT: 26

LOCAL ROAD

Good

Over: CREEK

098102901, Winneshiek, IA

Built 2002 Load: 45.5 t ADT: 44

NB I-35

Good

Over: WINNEBAGO RIVER

2.3 mi. S of Jct. IA 9, Cerro Gordo, IA

Built 1970 Load: 45.6 t ADT: 10,500

LOCAL

Good

Over: BR PRAIRIE CREEK

083122301, Benton, IA

Built 1994 Load: 45.7 t ADT: 140

LOCAL

Good

Over: BR STEIN CK

084122802, Benton, IA

Built 1999 Load: 45.7 t ADT: 26

LOCAL

Good

Over: BR HINKLE CK

085112201, Benton, IA

Built 2001 Load: 45.7 t ADT: 40

SPRING CREEK RD

Good

Over: EAST BRANCH SPRING CREEK

87-11-01-04-10, Black Hawk, IA

Built 2005 Load: 45.7 t ADT: 88

SCHENK RD

Good

Over: TRIB TO CRANE CREEK

90-12-16-02-10, Black Hawk, IA

Built 2006 Load: 45.7 t ADT: 39

FM

Good

Over: SMALL STREAM

089072201, Buchanan, IA

Built 2007 Load: 45.7 t ADT: 59

LOCAL

Good

Over: BR LITTLE SIOUX RIVER

092382401, Buena Vista, IA

Built 2001 Load: 45.7 t ADT: 80

LOCAL

Good

Over: HARDIN CREEK

086311101, Calhoun, IA

Built 1994 Load: 45.7 t ADT: 40

LOCAL

Good

Over: PRARIE CREEK

086341005, Calhoun, IA

Built 1991 Load: 45.7 t ADT: 139

FM

Good

Over: PRARIE CREEK

086341504, Calhoun, IA

Built 1993 Load: 45.7 t ADT: 50

LOCAL

Good

Over: EAST CEDAR CREEK

087310301, Calhoun, IA

Built 2003 Load: 45.7 t ADT: 34

FM

Good

Over: HARDIN CREEK

087313501, Calhoun, IA

Built 2003 Load: 45.7 t ADT: 26

FM

Good

Over: PURGATORY CREEK

087322302, Calhoun, IA

Built 2006 Load: 45.7 t ADT: 469

FM

Good

Over: DD NO. 12

088312202, Calhoun, IA

Built 1990 Load: 45.7 t ADT: 180

FM

Good

Over: DD NO. 12

088312704, Calhoun, IA

Built 1998 Load: 45.7 t ADT: 180

INWOOD

Good

Over: DREDGE DITCH

088331902, Calhoun, IA

Built 2000 Load: 45.7 t ADT: 15

FM

Good

Over: DD NO. 1

088341002, Calhoun, IA

Built 1993 Load: 45.7 t ADT: 20

FM

Good

Over: D D 1-54

088341502, Calhoun, IA

Built 1994 Load: 45.7 t ADT: 26

FM

Good

Over: CAMP CR TRIB.

088343402, Calhoun, IA

Built 1994 Load: 45.7 t ADT: 60

FM

Good

Over: FIELD STREAM

082353601, Carroll, IA

Built 2006 Load: 45.7 t ADT: 34

FM

Good

Over: FIELD STREAM

083342804, Carroll, IA

Built 2005 Load: 45.7 t ADT: 1,075

FM

Good

Over: FIELD STREAM

083351806, Carroll, IA

Built 2007 Load: 45.7 t ADT: 358

FM

Good

Over: WEST NISHNABOTNA RIVER

083361601, Carroll, IA

Built 2008 Load: 45.7 t ADT: 34

210TH ST

Good

Over: BR SUGAR CR

081023301, Cedar, IA

Built 2007 Load: 45.7 t ADT: 71

FM

Good

Over: W ROCK CREEK

081030501, Cedar, IA

Built 2001 Load: 45.7 t ADT: 50

LOCAL

Good

Over: WEST ROCK CREEK

081032003, Cedar, IA

Built 1996 Load: 45.7 t ADT: 34

LOCAL

Good

Over: CREEK

081040803, Cedar, IA

Built 2004 Load: 45.7 t ADT: 90

BAKER AVE

Good

Over: COON CREEK

081040804, Cedar, IA

Built 2001 Load: 45.7 t ADT: 26

ECHO AVE

Good

Over: MASONS CREEK

081041404, Cedar, IA

Built 2006 Load: 45.7 t ADT: 20

143RD ST

Good

Over: CLEAR CREEK

082042805, Cedar, IA

Built 2023 Load: 45.7 t ADT: 45

225TH ST

Good

Over: BAD LANDS DRAW

096193503, Cerro Gordo, IA

Built 2019 Load: 45.7 t ADT: 30

270TH AVE

Good

Over: MONTGOMERY CREEK

094361302, Clay, IA

Built 1993 Load: 45.7 t ADT: 26

340TH ST

Good

Over: PICKEREL RUN

096350701, Clay, IA

Built 1991 Load: 45.7 t ADT: 46

260TH AVE

Good

Over: BIG MEADOW CREEK

097363502, Clay, IA

Built 2000 Load: 45.7 t ADT: 30

LACE AVE

Good

Over: SMALL STREAM

093032510, Clayton, IA

Built 2005 Load: 45.7 t ADT: 11

FM

Good

Over: STREAM

070270904, Decatur, IA

Built 2006 Load: 45.7 t ADT: 219

Showing 15,301-15,350 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.