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

LOCAL

Good

Over: COON CREEK

076213302, Marion, IA

Built 2008 Load: 38.6 t ADT: 16

692ND AVE

Good

Over: AVERY CREEK

071160804, Monroe, IA

Built 2012 Load: 38.6 t ADT: 26

YORK AVE

Good

Over: MUD CREEK

078010102, Muscatine, IA

Built 2022 Load: 38.6 t ADT: 82

B63 (490TH ST)

Good

Over: DD 63

094332901, Palo Alto, IA

Built 2014 Load: 38.6 t ADT: 309

B55 430TH ST

Good

Over: DD #61

095312601, Palo Alto, IA

Built 2016 Load: 38.6 t ADT: 478

OTTER AVE

Good

Over: PLYMOUTH CREEK

924417210, Plymouth, IA

Built 2016 Load: 38.6 t ADT: 26

FOX AVE

Good

Over: BOYER CREEK

089370502, Sac, IA

Built 2021 Load: 38.6 t ADT: 15

UTAH AVE

Good

Over: EAST RIVER

070323302, Taylor, IA

Built 2019 Load: 38.6 t ADT: 34

LOCAL

Good

Over: LITTLE SOAP CREEK

071151304, Wapello, IA

Built 2010 Load: 38.6 t ADT: 30

BIRCH AVE

Good

Over: SMITH CREEK

077092902, Washington, IA

Built 2020 Load: 38.6 t ADT: 34

DAKOTA AVE

Good

Over: BUTTRICK CREEK

086301502, Webster, IA

Built 2011 Load: 38.6 t ADT: 72

BAXTER AVE

Good

Over: SOUTH LIZARD CREEK

089300802, Webster, IA

Built 2012 Load: 38.6 t ADT: 26

270TH ST

Good

Over: STREAM

091123601, Bremer, IA

Built 2000 Load: 38.7 t ADT: 49

LOCAL

Good

Over: SMALL STREAM

090171706, Butler, IA

Built 1998 Load: 38.7 t ADT: 26

UNION AVE

Good

Over: SMALL

093150402, Butler, IA

Built 2005 Load: 38.7 t ADT: 26

NEWELL AVE

Good

Over: SMALL STREAM

091160802, Butler, IA

Built 2006 Load: 38.7 t ADT: 34

250TH ST

Good

Over: SMALL STREAM

091162101, Butler, IA

Built 2007 Load: 38.7 t ADT: 16

LOCAL

Good

Over: CREEK

094120801, Chickasaw, IA

Built 1999 Load: 38.7 t ADT: 73

LOCAL

Good

Over: PLUM CREEK

095121008, Chickasaw, IA

Built 1989 Load: 38.7 t ADT: 73

LOCAL

Good

Over: ELK CREEK

096130601, Chickasaw, IA

Built 1991 Load: 38.7 t ADT: 30

LOCAL

Good

Over: CREEK

097113004, Chickasaw, IA

Built 2004 Load: 38.7 t ADT: 21

LOCAL-CO LINE

Good

Over: WAPSIPINICON RIVER

097142401, Chickasaw, IA

Built 1991 Load: 38.7 t ADT: 82

120TH ST

Good

Over: SIMMONS CREEK

083E51401, Clinton, IA

Built 2005 Load: 38.7 t ADT: 21

FM

Good

Over: FOX RIVER

069152406, Davis, IA

Built 1991 Load: 38.7 t ADT: 50

LAKE ROAD

Good

Over: DRAINAGE DITCH

072012103, Des Moines, IA

Built 2007 Load: 38.7 t ADT: 47

LOCAL

Good

Over: STONY CREEK

098381701, Dickinson, IA

Built 1992 Load: 38.7 t ADT: 15

M AVE.

Good

Over: VOLGA RIVER

093083002, Fayette, IA

Built 1992 Load: 38.7 t ADT: 44

LOC 200TH AVE

Good

Over: DRAINAGE DITCH #90

099272902, Kossuth, IA

Built 1984 Load: 38.7 t ADT: 35

LOCAL

Good

Over: LITTLE WHITEBREAST

073211904, Lucas, IA

Built 2003 Load: 38.7 t ADT: 47

LOCAL

Good

Over: STREAM

076182701, Marion, IA

Built 1990 Load: 38.7 t ADT: 51

FM

Good

Over: GRAYS CREEK

073160703, Monroe, IA

Built 1989 Load: 38.7 t ADT: 45

FM-145TH STREET

Good

Over: HONEY CREEK

077443310, Pottawattamie, IA

Built 2003 Load: 38.7 t ADT: 79

LOCAL

Good

Over: STREAM

088362002, Sac, IA

Built 2001 Load: 38.7 t ADT: 30

LOCAL

Good

Over: WOLF CREEK

086163106, Tama, IA

Built 1992 Load: 38.7 t ADT: 44

FM

Good

Over: 12 MILE CREEK

073302702, Union, IA

Built 1990 Load: 38.7 t ADT: 45

LOCAL

Good

Over: CHARITON RIVER

069220903, Wayne, IA

Built 1992 Load: 38.7 t ADT: 30

FM

Good

Over: DRAINAGE

100073404, Winneshiek, IA

Built 1990 Load: 38.7 t ADT: 236

LOCAL

Good

Over: SHOAL CREEK

067171903, Appanoose, IA

Built 1988 Load: 38.8 t ADT: 11

LOCAL

Good

Over: CHARITON RIVER

069171603, Appanoose, IA

Built 1999 Load: 38.8 t ADT: 82

LOCAL

Good

Over: E NISHNABOTNA RIVER

080352501, Audubon, IA

Built 1998 Load: 38.8 t ADT: 103

130TH ST

Good

Over: CREEK

081 34 24 01, Audubon, IA

Built 2021 Load: 38.8 t ADT: 20

GOLDFINCH AVE

Good

Over: CREEK

081350702, Audubon, IA

Built 2021 Load: 38.8 t ADT: 50

LOCAL

Good

Over: SMALL STREAM

093182201, Butler, IA

Built 1992 Load: 38.8 t ADT: 30

FM

Good

Over: MIDDLE RACCOON RIVER

082340201, Carroll, IA

Built 1995 Load: 38.8 t ADT: 100

FM 160TH AVE

Good

Over: STONY CREEK

097373002, Clay, IA

Built 1990 Load: 38.8 t ADT: 34

US 52

Good

Over: BRANCH PONY CREEK

2.8 MI. N OF JCT IA 128, Clayton, IA

Built 1975 Load: 38.8 t ADT: 1,740

LOCAL

Good

Over: FABIUS CREEK

067140806, Davis, IA

Built 2004 Load: 38.8 t ADT: 45

LOCAL

Good

Over: S WYACONDAH DITCH

068132702, Davis, IA

Built 1998 Load: 38.8 t ADT: 90

IRIS BLVD

Good

Over: FOX RIVER

069140906, Davis, IA

Built 2015 Load: 38.8 t ADT: 80

LOC 285 AVE

Good

Over: PLUM CREEK

087030608, Delaware, IA

Built 1991 Load: 38.8 t ADT: 39

Showing 13,801-13,850 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.