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

35TH ST

Good

Over: MILL CREEK

084E31709, Jackson, IA

Built 2019 Load: 41.5 t ADT: 236

30TH AVE

Good

Over: S FORK MAQUOKETA RIVER

085E13304, Jackson, IA

Built 2014 Load: 41.5 t ADT: 45

188TH ST

Good

Over: LYTLE CREEK

085E20503, Jackson, IA

Built 2021 Load: 41.5 t ADT: 15

VETCH BLVD

Good

Over: DRAINAGE

072082710, Jefferson, IA

Built 2011 Load: 41.5 t ADT: 420

100TH AVE

Good

Over: BEAR CREEK

084022704, Jones, IA

Built 2008 Load: 41.5 t ADT: 128

P30 90TH AVE

Good

Over: BLACK CAT CREEK

096290402, Kossuth, IA

Built 2020 Load: 41.5 t ADT: 339

US 151 & IA 13

Good

Over: BIG CREEK

1.1 MI. N OF JCT. US 30, Linn, IA

Built 1998 Load: 41.5 t ADT: 9,650

LOCAL ROAD

Good

Over: LITTLE ROCK RIVER

098441501, Lyon, IA

Built 1997 Load: 41.5 t ADT: 81

30TH PL

Good

Over: CREEK

076212804, Marion, IA

Built 2006 Load: 41.5 t ADT: 26

US 59

Good

Over: FARM CREEK

0.8 MI. S OF Jct. SR H12, Mills, IA

Built 1995 Load: 41.5 t ADT: 940

NATURE AVE

Good

Over: WILLOW CREEK

9345360220, Plymouth, IA

Built 2018 Load: 41.5 t ADT: 30

DIAMOND AVE

Good

Over: INDIAN CREEK

9348102100016, Plymouth, IA

Built 2023 Load: 41.5 t ADT: 45

CHESTNUT ROAD

Good

Over: JORDAN CREEK

074391705, Pottawattamie, IA

Built 2018 Load: 41.5 t ADT: 15

BEECHNUT RD

Good

Over: FARM CREEK

074392201, Pottawattamie, IA

Built 2017 Load: 41.5 t ADT: 15

BEECHNUT ROAD

Good

Over: STREAM

074422401, Pottawattamie, IA

Built 2019 Load: 41.5 t ADT: 60

538TH ST

Good

Over: DRAINAGE

075382404, Pottawattamie, IA

Built 2017 Load: 41.5 t ADT: 34

IDELWOOD ROAD

Good

Over: SLOCUM CREEK

075400301, Pottawattamie, IA

Built 2021 Load: 41.5 t ADT: 11

320TH STREET

Good

Over: STREAM

075410902, Pottawattamie, IA

Built 2015 Load: 41.5 t ADT: 20

ELMTREE ROAD

Good

Over: STREAM

075412603, Pottawattamie, IA

Built 2018 Load: 41.5 t ADT: 29

ELMTREE ROAD

Good

Over: MIDDLE SILVER CREEK

075412901, Pottawattamie, IA

Built 2012 Load: 41.5 t ADT: 29

DELTA AVE

Good

Over: LITTLE SILVER CREEK

075422607, Pottawattamie, IA

Built 2012 Load: 41.5 t ADT: 79

COTTONWOOD ROAD

Good

Over: LITTLE SILVER CREEK

075423503, Pottawattamie, IA

Built 2015 Load: 41.5 t ADT: 50

PINOAK ROAD

Good

Over: KEG CREEK

076410803, Pottawattamie, IA

Built 2012 Load: 41.5 t ADT: 40

MORTON AVENUE

Good

Over: KEG CREEK

076410805, Pottawattamie, IA

Built 2020 Load: 41.5 t ADT: 29

SUMAC ROAD

Good

Over: WALNUT CREEK

077383501, Pottawattamie, IA

Built 2017 Load: 41.5 t ADT: 11

198TH ST

Good

Over: HONEY CREEK

077430504, Pottawattamie, IA

Built 2013 Load: 41.5 t ADT: 79

WHIPPOORWILL RD

Good

Over: POTATO CREEK

077431201, Pottawattamie, IA

Built 2017 Load: 41.5 t ADT: 89

V 21 (200TH ST)

Good

Over: NORTH ENGLISH RIVER

079131708, Poweshiek, IA

Built 2012 Load: 41.5 t ADT: 15

370TH AVE

Good

Over: STONY CREEK

080141001, Poweshiek, IA

Built 2022 Load: 41.5 t ADT: 40

FM

Good

Over: E BR W NISHNABOTNA RIVER

078380506, Shelby, IA

Built 1998 Load: 41.5 t ADT: 29

S GRAND AVE

Good

Over: OVERFLOW CHANNEL

0.4 Mi N of S 16th Street, Story, IA

Built 2021 Load: 41.5 t ADT: 4,085

FM

Good

Over: BRANCH IOWA RIVER

084152902, Tama, IA

Built 2011 Load: 41.5 t ADT: 39

FM

Good

Over: W. FORK CROOKED CREEK

075073204, Washington, IA

Built 2003 Load: 41.5 t ADT: 660

LOCAL

Good

Over: GOOSE CREEK

076061602, Washington, IA

Built 1988 Load: 41.5 t ADT: 26

LOCAL

Good

Over: GOOSE CREEK

076062302, Washington, IA

Built 1990 Load: 41.5 t ADT: 15

FM

Good

Over: ENGLISH RIVER

077061704, Washington, IA

Built 1999 Load: 41.5 t ADT: 1,460

LOCAL ROAD

Good

Over: CAMP CREEK

077073104, Washington, IA

Built 1991 Load: 41.5 t ADT: 100

FM

Good

Over: ENGLISH RIVER

077080702, Washington, IA

Built 1999 Load: 41.5 t ADT: 1,400

FM

Good

Over: ENGLISH RIVER

077090302, Washington, IA

Built 1998 Load: 41.5 t ADT: 270

LOCAL

Good

Over: SMITH CREEK

077092602, Washington, IA

Built 1989 Load: 41.5 t ADT: 50

NB US 218

Good

Over: E. FORK CROOKED CREEK

1.1 mi. S of Jct. SR G62, Washington, IA

Built 1997 Load: 41.5 t ADT: 6,400

WATROUS

Good

Over: UP RR

070210501, Wayne, IA

Built 2014 Load: 41.5 t ADT: 40

LOCAL

Good

Over: BOONE RIVER

087272505, Webster, IA

Built 1992 Load: 41.5 t ADT: 71

LOCAL

Good

Over: WOLF CREEK

087441904, Woodbury, IA

Built 2004 Load: 41.5 t ADT: 26

L36

Good

Over: COON CREEK

088433602, Woodbury, IA

Built 2021 Load: 41.5 t ADT: 180

LOCAL

Good

Over: STREAM

0894218, Woodbury, IA

Built 2004 Load: 41.5 t ADT: 34

FM

Good

Over: DRAINAGE DITCH 107

093253202, Wright, IA

Built 2004 Load: 41.5 t ADT: 508

FM

Good

Over: MAPLE CREEK

087413504, Ida, IA

Built 2007 Load: 41.6 t ADT: 459

A42 240TH ST

Good

Over: MUD CREEK

098462201, Lyon, IA

Built 2003 Load: 41.6 t ADT: 698

PAMMEL ST PARK

Good

Over: MIDDLE RIVER

N entrance of Pammel Park, Madison, IA

Built 2003 Load: 41.6 t

Showing 14,601-14,650 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.