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

130TH ST

Good

Over: UNNAMED STREAM

090051901, Delaware, IA

Built 2022 Load: 45.7 t ADT: 45

200 TH

Good

Over: EAST BUTTRICKS CREEK

084293001, Greene, IA

Built 1990 Load: 45.7 t ADT: 20

LOCAL ROAD

Good

Over: WOLF CREEK

086182601, Grundy, IA

Built 2001 Load: 45.7 t ADT: 59

FM

Good

Over: HOG RUN

079100704, Iowa, IA

Built 1999 Load: 45.7 t ADT: 2,760

D61

Good

Over: LYTLES CREEK

R2ET86NS21SE, Jackson, IA

Built 2016 Load: 45.7 t ADT: 660

W 93RD ST S

Good

Over: CALHOUN CREEK

078200702, Jasper, IA

Built 1999 Load: 45.7 t ADT: 11

JONES-DELEWARE

Good

Over: CLINE CREEK

086030403, Jones, IA

Built 2006 Load: 45.7 t ADT: 59

FM 130TH ST

Good

Over: HINE CREEK

094291901, Kossuth, IA

Built 2006 Load: 45.7 t ADT: 569

LOC 110TH AVE

Good

Over: DRAINAGE SITCH 9

094293101, Kossuth, IA

Built 2007 Load: 45.7 t ADT: 26

LOC 30TH AVE

Good

Over: LOTTS CREEK

096300402, Kossuth, IA

Built 2007 Load: 45.7 t ADT: 21

ASHLEY AVE

Good

Over: PETERSON CREEK

099480902, Lyon, IA

Built 2022 Load: 45.7 t ADT: 50

INDIANA DR

Good

Over: COAL CREEK

076212004, Marion, IA

Built 2011 Load: 45.7 t ADT: 900

E29 SUMMIT RD

Good

Over: CREEK

084182902, Marshall, IA

Built 2005 Load: 45.7 t ADT: 717

320TH ST

Good

Over: CREEK

1/8 Mi. W. of Balsam Ave., Mitchell, IA

Built 2020 Load: 45.7 t ADT: 26

370TH ST

Good

Over: ROCK CREEK

0.4 Mi W Echo Ave, Mitchell, IA

Built 2018 Load: 45.7 t ADT: 29

FM

Good

Over: PRAIRIE CREEK

094311303, Palo Alto, IA

Built 2005 Load: 45.7 t ADT: 681

FM

Good

Over: DD #48

094322601, Palo Alto, IA

Built 2005 Load: 45.7 t ADT: 669

FM

Good

Over: DD 98

094323005, Palo Alto, IA

Built 2005 Load: 45.7 t ADT: 709

FM

Good

Over: DD 63

094330801, Palo Alto, IA

Built 1995 Load: 45.7 t ADT: 34

270 ST

Good

Over: DD 63

094331803, Palo Alto, IA

Built 2000 Load: 45.7 t ADT: 21

FM

Good

Over: DD 84

094342601, Palo Alto, IA

Built 2006 Load: 45.7 t ADT: 309

FM

Good

Over: DD 84

094342601, Palo Alto, IA

Built 2006 Load: 45.7 t ADT: 309

LOCAL

Good

Over: DD 61

095312301, Palo Alto, IA

Built 1997 Load: 45.7 t ADT: 15

LOCAL

Good

Over: STREAM

095322806, Palo Alto, IA

Built 1998 Load: 45.7 t ADT: 11

FM

Good

Over: SILVER CREEK

095342401, Palo Alto, IA

Built 2006 Load: 45.7 t ADT: 538

280TH ST

Good

Over: MINNIE BROOK

090450501, Plymouth, IA

Built 2004 Load: 45.7 t ADT: 15

240TH ST

Good

Over: RATHBURN CREEK

091431701, Plymouth, IA

Built 2000 Load: 45.7 t ADT: 34

MARBLE AVE

Good

Over: WHISKEY CREEK

091452302, Plymouth, IA

Built 2003 Load: 45.7 t ADT: 34

270TH ST

Good

Over: PERRY CREEK

9147350120, Plymouth, IA

Built 2018 Load: 45.7 t ADT: 80

DIAMOND AVE

Good

Over: WESTFIELD CREEK

092481502, Plymouth, IA

Built 2002 Load: 45.7 t ADT: 15

130TH ST

Good

Over: MINK CREEK

093462101, Plymouth, IA

Built 2004 Load: 45.7 t ADT: 60

FM

Good

Over: BEAVER CREEK

093320302, Pocahontas, IA

Built 2005 Load: 45.7 t ADT: 249

LOCAL

Good

Over: WALNUT CREEK

069292102, Ringgold, IA

Built 2006 Load: 45.7 t ADT: 26

130TH ST

Good

Over: CREEK

077E20209, Scott, IA

Built 2000 Load: 45.7 t ADT: 45

FM

Good

Over: CREEK

079E20602, Scott, IA

Built 1994 Load: 45.7 t ADT: 1,280

60TH AVE

Good

Over: CREEK

080E23102, Scott, IA

Built 1994 Load: 45.7 t ADT: 1,280

1800TH ST

Good

Over: W FORK W NISHNABOTNA

80838, Shelby, IA

Built 2017 Load: 45.7 t ADT: 26

LOCAL

Good

Over: SMALL STREAM

094451201, Sioux, IA

Built 2001 Load: 45.7 t ADT: 40

LOCAL

Good

Over: SMALL STREAM

095441702, Sioux, IA

Built 1992 Load: 45.7 t ADT: 60

LOCAL

Good

Over: SMALL STREAM

095443202, Sioux, IA

Built 1989 Load: 45.7 t ADT: 549

LOCAL

Good

Over: SMALL STREAM

096440302, Sioux, IA

Built 1999 Load: 45.7 t ADT: 30

B 30 370TH ST

Good

Over: NO NAME CREEK

096452701, Sioux, IA

Built 2018 Load: 45.7 t ADT: 988

LOCAL

Good

Over: SMALL STREAM

097462604, Sioux, IA

Built 1990 Load: 45.7 t ADT: 50

K24 DOGWOOD AVE

Good

Over: NO NAME CREEK

097473604, Sioux, IA

Built 2017 Load: 45.7 t ADT: 429

280TH ST

Good

Over: MARSHALL-STORY DD#2

0.3 Mi W 730th Ave, Story, IA

Built 2018 Load: 45.7 t ADT: 20

G38

Good

Over: DUTCH CREEK

075092101, Washington, IA

Built 2016 Load: 45.7 t ADT: 250

ENT RD

Good

Over: BRUSHY CREEK

087270204, Webster, IA

Built 1993 Load: 45.7 t ADT: 159

NB I-35

Good

Over: BUFFALO CREEK

0.5 mi. N of SR C25, Franklin, IA

Built 1973 Load: 45.8 t ADT: 8,450

SB I-35

Good

Over: BUFFALO CREEK

0.5 mi. N of SR C25, Franklin, IA

Built 1973 Load: 45.8 t ADT: 8,450

US 218 SB

Good

Over: SKUNK RIVER

4.7 mi. S of S Jct. US 34, Henry, IA

Built 2003 Load: 45.8 t ADT: 4,850

Showing 15,351-15,400 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.