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

FM

Good

Over: BEAVER CREEK

081271604, Dallas, IA

Built 1986 Load: 33.5 t ADT: 20

TRAPPERS BAY ST PK

Good

Over: SILVER LAKE CAUSEWAY

IN TRAPPERS BAY ST.PARK, Dickinson, IA

Built 1984 Load: 33.5 t

US 18 EB

Good

Over: IA NORTHERN RR & STREAM

1.1 mi. E of Jct. SR S70, Floyd, IA

Built 1998 Load: 33.5 t ADT: 5,350

US 34 WB

Good

Over: BIG CEDAR CREEK

1.6 MI W OF JCT. SR V-63, Jefferson, IA

Built 2006 Load: 33.5 t ADT: 3,900

JASPER AVE

Good

Over: STREAM

000000000, Johnson, IA

Built 1985 Load: 33.5 t ADT: 970

FM

Good

Over: OTTER CREEK

073031306, Louisa, IA

Built 1975 Load: 33.5 t ADT: 70

LOCAL

Good

Over: MUCHAKINOCK CREEK

075162701, Mahaska, IA

Built 1985 Load: 33.5 t ADT: 71

IA 9

Good

Over: DRAINAGE DITCH

1.9 mi. E of US 59, Osceola, IA

Built 1978 Load: 33.5 t ADT: 2,020

FM

Good

Over: DITCH

090431101, Plymouth, IA

Built 1991 Load: 33.5 t ADT: 290

FM-290TH STREET

Good

Over: KEG CREEK

075420102, Pottawattamie, IA

Built 1982 Load: 33.5 t ADT: 20

FM-DOGWOOD RD

Good

Over: KEG CREEK

075422703, Pottawattamie, IA

Built 1982 Load: 33.5 t ADT: 71

FM RD F32

Good

Over: WEST NISHNABOTNA RIVER

080382205, Shelby, IA

Built 1985 Load: 33.5 t ADT: 319

LOCAL

Good

Over: CREEK

068323101, Taylor, IA

Built 2000 Load: 33.5 t ADT: 15

230TH AVE

Good

Over: BRANCH FLANK CREEK

074220201, Warren, IA

Built 2019 Load: 33.5 t ADT: 62

LOCAL

Good

Over: STREAM

091263002, Wright, IA

Built 1997 Load: 33.5 t ADT: 11

LOCAL

Good

Over: STREAM

091263102, Wright, IA

Built 1996 Load: 33.5 t ADT: 15

INDIAN AVE

Good

Over: STREAM

77323308, Adair, IA

Built 2012 Load: 33.6 t ADT: 15

130TH ST

Good

Over: CRAINS CREEK

093132201, Bremer, IA

Built 2012 Load: 33.6 t ADT: 33

150TH ST

Good

Over: CRAINS CREEK

093133501, Bremer, IA

Built 2012 Load: 33.6 t ADT: 33

LOCAL

Good

Over: MAPLE RIVER

090382102, Buena Vista, IA

Built 2005 Load: 33.6 t ADT: 30

FM

Good

Over: PURGATORY CREEK

085330102, Carroll, IA

Built 1983 Load: 33.6 t ADT: 26

LOCAL-520TH ST.

Good

Over: W FORK LITTLE SIOUX

092422601, Cherokee, IA

Built 2010 Load: 33.6 t ADT: 15

FM

Good

Over: LITTLE CEDAR RIVER

094140401, Chickasaw, IA

Built 1971 Load: 33.6 t ADT: 49

LOCAL 265 ST

Good

Over: PLUM CREEK

088032903, Delaware, IA

Built 1979 Load: 33.6 t ADT: 44

LOC MILL RD

Good

Over: UPPER IOWA RIVER

100122003, Howard, IA

Built 1992 Load: 33.6 t ADT: 73

ENTRY ROAD

Good

Over: UNNAMED DRAINAGE

500' S. OF 88TH AVE., Jasper, IA

Built 2015 Load: 33.6 t ADT: 159

200TH ST

Good

Over: DRAINAGE

092462603, Plymouth, IA

Built 2006 Load: 33.6 t ADT: 71

DIAMOND AVE

Good

Over: BROKEN KETTLE CREEK

090480304, Plymouth, IA

Built 2003 Load: 33.6 t ADT: 26

FM

Good

Over: WALNUT CREEK

081131001, Poweshiek, IA

Built 1983 Load: 33.6 t ADT: 30

IA 60 SB

Good

Over: WILLOW CREEK

0.7 mi. N of Jct. SR B40, Sioux, IA

Built 2003 Load: 33.6 t ADT: 2,485

IA 60 NB

Good

Over: WILLOW CREEK

0.7 mi. N of Jct. SR B40, Sioux, IA

Built 2003 Load: 33.6 t ADT: 2,485

IA 5 SB

Good

Over: MIDDLE RIVER

1.4 mi. S of jct. SR G-16, Warren, IA

Built 1997 Load: 33.6 t ADT: 5,650

LOCAL

Good

Over: NORTH FORK YELLOW RIVER

096070402, Winneshiek, IA

Built 1991 Load: 33.6 t ADT: 39

LOCAL

Good

Over: CREEK

100092203, Winneshiek, IA

Built 1980 Load: 33.6 t ADT: 20

G53 270TH ST

Good

Over: BRANCH OF NINE MILE RUN

1.5 mi E of IA 25 on G53, Adair, IA

Built 2016 Load: 33.7 t ADT: 26

LOCAL RD

Good

Over: BR LEWIS JONES CREEK

098040704, Allamakee, IA

Built 2002 Load: 33.7 t ADT: 20

BIG ROCK RD

Good

Over: NO NAME CREEK

CITY CULVERT NO. 31C, Black Hawk, IA

Built 2009 Load: 33.7 t ADT: 100

BIG ROCK RD

Good

Over: NO NAME CREEK

CITY CULVERT NO. 32C, Black Hawk, IA

Built 2009 Load: 33.7 t ADT: 100

LOCAL

Good

Over: IOWAY CREEK

085251603, Boone, IA

Built 2006 Load: 33.7 t ADT: 26

3RD AVE NW

Good

Over: DRY RUN CREEK

BETWEEN 5TH & 6TH ST NW, Bremer, IA

Built 2016 Load: 33.7 t ADT: 330

5TH AVE NE

Good

Over: DRAINAGE DITCH

0.5 MI E OF BREMER RD, Bremer, IA

Built 2016 Load: 33.7 t ADT: 113

COOTS BLVD

Good

Over: SMALL CREEK

088083103, Buchanan, IA

Built 2015 Load: 33.7 t ADT: 79

440TH ST

Good

Over: CREEK

093411601, Cherokee, IA

Built 2003 Load: 33.7 t ADT: 26

LOCAL 430TH ST

Good

Over: CREEK

093420801, Cherokee, IA

Built 1998 Load: 33.7 t ADT: 20

R AVENUE

Good

Over: UNNAMED STREAM

091400104, Cherokee, IA

Built 2006 Load: 33.7 t ADT: 30

FM

Good

Over: WAPSIPINICON RIVER

097142903, Chickasaw, IA

Built 1996 Load: 33.7 t ADT: 29

460TH ST

Good

Over: STREAM

094370801, Clay, IA

Built 2005 Load: 33.7 t ADT: 21

390TH ST

Good

Over: PRARIE CREEK

095370201, Clay, IA

Built 2006 Load: 33.7 t ADT: 21

370TH ST

Good

Over: STREAM

096352701, Clay, IA

Built 1998 Load: 33.7 t ADT: 41

BELGIAM RD

Good

Over: KLEINLEIN HOLLOW

091060204, Clayton, IA

Built 2004 Load: 33.7 t ADT: 30

Showing 12,451-12,500 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.