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

IA 7

Good

Over: NORTH RACCOON RIVER

3.2 mi. W of SR M54, Buena Vista, IA

Built 2002 Load: 37.6 t ADT: 2,050

RIDGE AVE.

Good

Over: SMALL STREAM

092163602, Butler, IA

Built 1991 Load: 37.6 t ADT: 35

LOCAL

Good

Over: CRAB APPLE CREEK

093170207, Butler, IA

Built 1985 Load: 37.6 t ADT: 82

LOCAL

Good

Over: BRUSHY FORK CREEK

083352102, Carroll, IA

Built 2001 Load: 37.6 t ADT: 89

LOCAL

Good

Over: MIDDLE RACCOON RIVER

084342702, Carroll, IA

Built 1997 Load: 37.6 t ADT: 79

INDEPENDENCE RD

Good

Over: INDIAN RIVER

076371701, Cass, IA

Built 2000 Load: 37.6 t ADT: 35

LOCAL

Good

Over: INDIAN CREEK

077371801, Cass, IA

Built 2004 Load: 37.6 t ADT: 40

120TH

Good

Over: BAILEY CREEK

0.6 MI E OF GROUSE AVE, Cerro Gordo, IA

Built 2011 Load: 37.6 t ADT: 30

290TH

Good

Over: SHELL ROCK RIVER

097193503, Cerro Gordo, IA

Built 1998 Load: 37.6 t ADT: 47

FM 560TH ST

Good

Over: MAPLE RIVER

091391701, Cherokee, IA

Built 2009 Load: 37.6 t ADT: 40

LOCAL-480TH ST.

Good

Over: CREEK

092410101, Cherokee, IA

Built 1999 Load: 37.6 t ADT: 15

LOCAL 470TH ST

Good

Over: CREEK

093393501, Cherokee, IA

Built 2000 Load: 37.6 t ADT: 11

LOCAL 420TH ST

Good

Over: CREEK

093420501, Cherokee, IA

Built 1997 Load: 37.6 t ADT: 20

B AVENUE

Good

Over: DRAINAGE

090420802, Cherokee, IA

Built 1998 Load: 37.6 t ADT: 26

110TH AVE

Good

Over: SMALL CREEK

071270804, Clarke, IA

Built 2020 Load: 37.6 t ADT: 40

190TH AVE

Good

Over: WHITE BREAST CREEK

072262206, Clarke, IA

Built 2017 Load: 37.6 t ADT: 89

320TH AVE

Good

Over: STREAM

097351102, Clay, IA

Built 2007 Load: 37.6 t ADT: 21

FM 190TH AVE

Good

Over: LITTLE SIOUX RIVER

097372702, Clay, IA

Built 1992 Load: 37.6 t ADT: 50

291ST

Good

Over: SODUS CREEK

080E51207, Clinton, IA

Built 2004 Load: 37.6 t ADT: 240

265TH AVE.

Good

Over: SMALL STREAM

083E30206, Clinton, IA

Built 1994 Load: 37.6 t ADT: 33

LOCAL

Good

Over: EAST SOLDIER RIVER

084411301, Crawford, IA

Built 1990 Load: 37.6 t ADT: 62

LOCAL

Good

Over: TRIB FOX

069123601, Davis, IA

Built 2010 Load: 37.6 t ADT: 20

195TH ST

Good

Over: STREAM

089052402, Delaware, IA

Built 2019 Load: 37.6 t ADT: 59

195TH ST

Good

Over: STREAM

089052302, Delaware, IA

Built 2019 Load: 37.6 t ADT: 70

LOCAL

Good

Over: DRAINAGE DITCH

072013207, Des Moines, IA

Built 2005 Load: 37.6 t ADT: 47

LOCAL

Good

Over: LAKE CHANNEL

099362904, Dickinson, IA

Built 2010 Load: 37.6 t ADT: 1,120

BRIDGE ST

Good

Over: CANAL

000000000, Dickinson, IA

Built 2010 Load: 37.6 t ADT: 232

LAKESHORE DR

Good

Over: CANAL

Lakeshore Drive (East), Dickinson, IA

Built 2012 Load: 37.6 t ADT: 232

ARENSDORF RD

Good

Over: OTTER CREEK

087E23601, Dubuque, IA

Built 2019 Load: 37.6 t ADT: 88

OLDE MASSEY RD

Good

Over: CREEK

088E31504, Dubuque, IA

Built 2018 Load: 37.6 t ADT: 471

BIERMAN RD

Good

Over: WHITEWATER CREEK

088011416, Dubuque, IA

Built 2019 Load: 37.6 t ADT: 39

Y21 BUDD RD

Good

Over: CREEK

089E11011, Dubuque, IA

Built 2018 Load: 37.6 t ADT: 314

K AVE.

Good

Over: LITTLE VOLGA

092082804, Fayette, IA

Built 1998 Load: 37.6 t ADT: 1,719

140 TH

Good

Over: CEDAR CREEK

085322805, Greene, IA

Built 1990 Load: 37.6 t ADT: 51

US 20

Good

Over: STREAM

2.7 MILES W OF JCT SR T55, Grundy, IA

Built 1999 Load: 37.6 t ADT: 13,500

VICTORY TRAIL

Good

Over: BAYS BRANCH

079300302, Guthrie, IA

Built 2020 Load: 37.6 t ADT: 20

150TH ST

Good

Over: DD #8

094250701, Hancock, IA

Built 2012 Load: 37.6 t ADT: 41

CRANE AVE

Good

Over: BOONE RIVER

094260902, Hancock, IA

Built 2012 Load: 37.6 t ADT: 15

170TH ST

Good

Over: BOONE RIVER

095263103, Hancock, IA

Built 2021 Load: 37.6 t ADT: 15

BUS BROWN DR

Good

Over: DRAINAGE

East of Lincolnway, Harrison, IA

Built 2017 Load: 37.6 t ADT: 1,225

FM & 340TH ST

Good

Over: WILLOW RIVER

081420301, Harrison, IA

Built 2005 Load: 37.6 t ADT: 50

FM

Good

Over: PHILLIPS CREEK

073061204, Henry, IA

Built 1983 Load: 37.6 t ADT: 30

GEORGIA AVE

Good

Over: DD

Humboldt, Humboldt, IA

Built 2019 Load: 37.6 t ADT: 40

LOCAL

Good

Over: LITTLE BEAR CREEK

080110906, Iowa, IA

Built 2009 Load: 37.6 t ADT: 20

R AVE

Good

Over: SMALL STREAM

081101204, Iowa, IA

Built 2012 Load: 37.6 t ADT: 40

GI BOTTOMS RD

Good

Over: SMALL CREEK

085E62904, Jackson, IA

Built 2015 Load: 37.6 t ADT: 44

S 60TH AVE E

Good

Over: CARSON CREEK

079192601, Jasper, IA

Built 2016 Load: 37.6 t ADT: 240

257TH ST

Good

Over: UNNAMED STREAM

071102407, Jefferson, IA

Built 2022 Load: 37.6 t ADT: 190

SB I-380

Good

Over: WEST OTTER CREEK

2.7 mi. N of Jct. SR E34, Linn, IA

Built 1983 Load: 37.6 t ADT: 12,850

LOCAL ROAD

Good

Over: LITTLE ROCK RIVER

099433003, Lyon, IA

Built 1999 Load: 37.6 t ADT: 26

Showing 13,501-13,550 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.