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

230TH STREET

Good

Over: DRY MILL CREEK

093040801, Clayton, IA

Built 1993 Load: 49.8 t ADT: 44

FM

Good

Over: BUCK CREEK

082391602, Crawford, IA

Built 1994 Load: 49.8 t ADT: 26

FM

Good

Over: EAST BOYER RIVER

084371406, Crawford, IA

Built 1994 Load: 49.8 t ADT: 40

FM

Good

Over: CARTERS CREEK

067140103, Davis, IA

Built 2002 Load: 49.8 t ADT: 90

LOCAL

Good

Over: CARTERS LAKE

068143505, Davis, IA

Built 2006 Load: 49.8 t ADT: 80

SHALE AVE

Good

Over: N CHEQUEST LAKE CREEK

070123002, Davis, IA

Built 2000 Load: 49.8 t ADT: 80

HORNET RD

Good

Over: OTTER CREEK

094081409, Fayette, IA

Built 1991 Load: 49.8 t ADT: 15

130 TH

Good

Over: STREAM

085321503, Greene, IA

Built 2002 Load: 49.8 t ADT: 30

LOCAL

Good

Over: MIDDLE RIVER

078320608, Guthrie, IA

Built 2004 Load: 49.8 t ADT: 15

LOCAL

Good

Over: STREAM

081300503, Guthrie, IA

Built 2004 Load: 49.8 t ADT: 15

1340 180TH ST

Good

Over: WEST IOWA RIVER

095243001, Hancock, IA

Built 2005 Load: 49.8 t ADT: 21

FM

Good

Over: CRANE CREEK

099131702, Howard, IA

Built 1995 Load: 49.8 t ADT: 59

LOCAL

Good

Over: HILTON CREEK

080100503, Iowa, IA

Built 2005 Load: 49.8 t ADT: 50

FM

Good

Over: COPPER CREEK

084E52801, Jackson, IA

Built 1993 Load: 49.8 t ADT: 100

LOCAL

Good

Over: SUGAR CREEK

080172503, Jasper, IA

Built 1994 Load: 49.8 t ADT: 91

LOCAL

Good

Over: CROOKED CREEK

076102301, Keokuk, IA

Built 1994 Load: 49.8 t ADT: 90

LOCAL

Good

Over: ROCK CREEK

076123402, Keokuk, IA

Built 1993 Load: 49.8 t ADT: 45

FM

Good

Over: TRIB S. FORK ENGLISH RIV

077101203, Keokuk, IA

Built 2004 Load: 49.8 t ADT: 20

FM 360TH ST

Good

Over: MUD CREEK

098292505, Kossuth, IA

Built 1999 Load: 49.8 t ADT: 450

FM

Good

Over: JACK CREEK

066050402, Lee, IA

Built 1993 Load: 49.8 t ADT: 80

80TH ST N.W.

Good

Over: MORGAN CREEK

083082208, Linn, IA

Built 1992 Load: 49.8 t ADT: 295

LOCAL

Good

Over: CHARITON RIVER

071210803, Lucas, IA

Built 2007 Load: 49.8 t ADT: 73

LOCAL

Good

Over: NORTH CEDAR CREEK

073203204, Lucas, IA

Built 2008 Load: 49.8 t ADT: 21

LOCAL

Good

Over: ENGLISH CREEK

073211103, Lucas, IA

Built 2002 Load: 49.8 t ADT: 35

LOCAL RD

Good

Over: N FORK CLANTON CREEK

074280304, Madison, IA

Built 1993 Load: 49.8 t ADT: 50

LOCAL

Good

Over: MINERVA CR

084201501, Marshall, IA

Built 2006 Load: 49.8 t ADT: 30

LOCAL

Good

Over: LINN CREEK

084203601, Marshall, IA

Built 1999 Load: 49.8 t ADT: 51

FM

Good

Over: ASHER CREEK

085182801, Marshall, IA

Built 2004 Load: 49.8 t ADT: 29

FM

Good

Over: DD 2

076043001, Muscatine, IA

Built 2004 Load: 49.8 t ADT: 110

322ND ST

Good

Over: BR OF W F LITTLE SIOUX

090442503, Plymouth, IA

Built 1998 Load: 49.8 t ADT: 210

QUARTZ AVE

Good

Over: WILLOW CREEK

093440102, Plymouth, IA

Built 1997 Load: 49.8 t ADT: 30

LOCAL ROAD

Good

Over: PONY CREEK

074431202, Pottawattamie, IA

Built 1998 Load: 49.8 t ADT: 229

FM-470TH STREET

Good

Over: BEDELL CREEK

077390104, Pottawattamie, IA

Built 1990 Load: 49.8 t ADT: 71

LOCAL

Good

Over: DEEP RIVER

078130406, Poweshiek, IA

Built 2004 Load: 49.8 t ADT: 11

LOCAL

Good

Over: LITTLE BEAR CREEK

080152104, Poweshiek, IA

Built 2003 Load: 49.8 t ADT: 30

LOCAL

Good

Over: WALNUT CREEK

081130602, Poweshiek, IA

Built 2004 Load: 49.8 t ADT: 34

FM

Good

Over: BRANCH 102 RIVER

070340801, Taylor, IA

Built 1998 Load: 49.8 t ADT: 45

LOCAL

Good

Over: LITTLE LICK CREEK

070093101, Van Buren, IA

Built 2004 Load: 49.8 t ADT: 47

LOCAL ROAD

Good

Over: BRANCH OTTER CREEK

075230804, Warren, IA

Built 1996 Load: 49.8 t ADT: 11

LOCAL

Good

Over: BRUSHY CREEK

087271104, Webster, IA

Built 2002 Load: 49.8 t ADT: 46

LOCAL

Good

Over: LIZARD CREEK

089301502, Webster, IA

Built 2001 Load: 49.8 t ADT: 72

LOCAL

Good

Over: LIZARD CREEK

089301701, Webster, IA

Built 1988 Load: 49.8 t ADT: 26

30TH AVE

Good

Over: N FORK BUFFALO CREEK

098260302, Winnebago, IA

Built 2000 Load: 49.8 t ADT: 21

LOCAL

Good

Over: WOLF CREEK

087443102, Woodbury, IA

Built 2006 Load: 49.8 t ADT: 26

LOCAL

Good

Over: EAGLE CREEK

091252102, Wright, IA

Built 2006 Load: 49.8 t ADT: 15

LOCAL

Good

Over: CREEK

094151702, Floyd, IA

Built 1990 Load: 49.9 t ADT: 26

INDIGO AVE

Good

Over: DRAINAGE DITCH #3

091210902, Franklin, IA

Built 2012 Load: 49.9 t ADT: 21

170 STREET

Good

Over: DRAINAGE

069400901, Fremont, IA

Built 1994 Load: 49.9 t ADT: 11

100TH ST

Good

Over: DRAINAGE

073360505, Montgomery, IA

Built 2015 Load: 49.9 t ADT: 15

ORIOLE AVE

Good

Over: SO BR LITTLE FLOYD RIVER

096410702, O'Brien, IA

Built 1989 Load: 49.9 t ADT: 409

Showing 15,751-15,800 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.