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

8TH ST NW

Good

Over: SMALL STREAM

0922033, Franklin, IA

Built 2013 Load: 40.8 t ADT: 349

IA 25

Good

Over: SOUTH RACCOON RIVER

0.3 mi. S of Jct. IA 44, Guthrie, IA

Built 1983 Load: 40.8 t ADT: 3,200

620 110TH ST

Good

Over: MID BR BOONE RIVER

094263601, Hancock, IA

Built 2008 Load: 40.8 t ADT: 35

FM

Good

Over: BIG CREEK

070060212, Henry, IA

Built 1989 Load: 40.8 t ADT: 160

D57 MILL CREEK RD

Good

Over: SMALL STREAM

086E40603, Jackson, IA

Built 2020 Load: 40.8 t ADT: 128

FM

Good

Over: MIDDLE WALNUT CREEK

073101403, Jefferson, IA

Built 2008 Load: 40.8 t ADT: 200

FM

Good

Over: TROY CREEK

071091503, Jefferson, IA

Built 2004 Load: 40.8 t ADT: 690

SWAN LAKE RD

Good

Over: BR IOWA RIVER

T80N, R07W, 3, Johnson, IA

Built 2018 Load: 40.8 t ADT: 131

D62 SPENCERS GROVE

Good

Over: SMALL NATURAL STREAM

T86N, R08W, 7, Linn, IA

Built 2018 Load: 40.8 t ADT: 707

EDGEWOOD RD

Good

Over: CRANDIC RR

082070704, Linn, IA

Built 2009 Load: 40.8 t ADT: 10,700

LOCAL

Good

Over: BR OF WHITEBREAST CREEK

072233505, Lucas, IA

Built 2000 Load: 40.8 t ADT: 73

EB US 30

Good

Over: TIMBER CREEK

3.0 MILES E OF JCT IA 14, Marshall, IA

Built 1996 Load: 40.8 t ADT: 7,300

390TH

Good

Over: CREEK

098161008, Mitchell, IA

Built 1986 Load: 40.8 t ADT: 39

MONUMENT AVE

Good

Over: SMALL STREAM

100160804, Mitchell, IA

Built 1987 Load: 40.8 t ADT: 786

150TH ST

Good

Over: WHISKEY CREEK

9343350110, Plymouth, IA

Built 2011 Load: 40.8 t ADT: 34

FM

Good

Over: BRANCH OF LOTTS CREEK

068280802, Ringgold, IA

Built 2009 Load: 40.8 t ADT: 89

LOCAL

Good

Over: STREAM

086360101, Sac, IA

Built 2008 Load: 40.8 t ADT: 34

LOCAL

Good

Over: STREAM

089380602, Sac, IA

Built 2008 Load: 40.8 t ADT: 34

LINDEN RD

Good

Over: SMALL STREAM

079380702, Shelby, IA

Built 2014 Load: 40.8 t ADT: 767

FM

Good

Over: DRY CREEK

096461202, Sioux, IA

Built 2010 Load: 40.8 t ADT: 957

SAND HILL TRAIL

Good

Over: WILCOX CREEK

S of INT w/ 250th St, Story, IA

Built 2018 Load: 40.8 t ADT: 120

730TH AVE

Good

Over: MINERVA CREEK

0.3 Mi S Co Line, Story, IA

Built 2020 Load: 40.8 t ADT: 30

100TH ST

Good

Over: MINERVA CREEK

085 21 02 01, Story, IA

Built 2012 Load: 40.8 t ADT: 20

E18 130TH ST

Good

Over: EAST INDIAN CREEK

E18 ov East Indian Creek, Story, IA

Built 2021 Load: 40.8 t ADT: 957

FM

Good

Over: BRANCH WOLF CREEK

085150204, Tama, IA

Built 1999 Load: 40.8 t ADT: 59

FM

Good

Over: DES MOINES RIVER

090291303, Webster, IA

Built 1995 Load: 40.8 t ADT: 2,234

D12 110TH ST

Good

Over: CREEK

089460701, Woodbury, IA

Built 2022 Load: 40.8 t ADT: 1,168

180TH ST

Good

Over: DRAINAGE

082E21801, Clinton, IA

Built 2007 Load: 40.9 t ADT: 30

US 169

Good

Over: CEDAR CREEK

0.9 MI. N of N JCT IA 92, Madison, IA

Built 1990 Load: 40.9 t ADT: 5,900

EB IA 163

Good

Over: CAMP CREEK

6.9 mi. E of Jct. US 65, Polk, IA

Built 2007 Load: 40.9 t ADT: 6,300

WB IA 163

Good

Over: CAMP CREEK

6.9 mi. E of Jct. U.S. 65, Polk, IA

Built 2007 Load: 40.9 t ADT: 6,300

NE 36TH

Good

Over: OTTER CREEK

080230700, Polk, IA

Built 1982 Load: 40.9 t ADT: 6,694

NB US 218

Good

Over: S FK LONG CREEK

1.5 MI. S OF JCT. IA 92, Washington, IA

Built 1997 Load: 40.9 t ADT: 5,650

FM

Good

Over: BOYLAN CREEK

092182303, Butler, IA

Built 2002 Load: 41.0 t ADT: 255

C13

Good

Over: COLD WATER CREEK

093170801, Butler, IA

Built 2006 Load: 41.0 t ADT: 511

LOCAL

Good

Over: FIELD STREAM

082350202, Carroll, IA

Built 2002 Load: 41.0 t ADT: 29

C43 550TH ST

Good

Over: MAPLE RIVER

091390801, Cherokee, IA

Built 2002 Load: 41.0 t ADT: 619

LOCAL

Good

Over: CREEK

094110701, Chickasaw, IA

Built 2006 Load: 41.0 t ADT: 154

FM

Good

Over: LITTLE WAPSIPINICON RVR

096132002, Chickasaw, IA

Built 2007 Load: 41.0 t ADT: 697

LOCAL

Good

Over: LITTLE TURKEY RIVER

097113304, Chickasaw, IA

Built 2007 Load: 41.0 t ADT: 34

FM

Good

Over: MUDDY CREEK

098352001, Dickinson, IA

Built 2002 Load: 41.0 t ADT: 325

FM

Good

Over: LITTLE SIOUX RIVER

098373405, Dickinson, IA

Built 2003 Load: 41.0 t ADT: 315

LOCAL

Good

Over: CREEK

097162001, Floyd, IA

Built 2005 Load: 41.0 t ADT: 29

US 20 EB

Good

Over: SOUTH BEAVER CREEK

0.1 MILE W OF JCT SR T19, Grundy, IA

Built 2003 Load: 41.0 t ADT: 4,550

IA 117

Good

Over: INDIAN CREEK

0.3 mi S of Jct. U.S. 65, Jasper, IA

Built 2001 Load: 41.0 t ADT: 1,580

FM

Good

Over: SMALL STREAM

073032101, Louisa, IA

Built 2002 Load: 41.0 t ADT: 480

188TH TRL

Good

Over: CREEK

072171803, Monroe, IA

Built 2000 Load: 41.0 t ADT: 45

FM

Good

Over: SEVEN MILE CREEK

073360801, Montgomery, IA

Built 2007 Load: 41.0 t ADT: 259

120TH STREET

Good

Over: MIDDLE TARKIO RIVER

070381303, Page, IA

Built 2003 Load: 41.0 t ADT: 20

FM

Good

Over: W FK W NISHNABOTNA RIVER

079380803, Shelby, IA

Built 1996 Load: 41.0 t ADT: 309

Showing 14,451-14,500 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.