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

P AVE

Good

Over: STONY CREEK

086140302, Tama, IA

Built 2021 Load: 32.7 t ADT: 39

M AVE

Good

Over: SMALL CREEK

086140602, Tama, IA

Built 2023 Load: 32.7 t ADT: 29

FM

Good

Over: BRANCH TWELVE MILE CREEK

086142003, Tama, IA

Built 2003 Load: 32.7 t ADT: 275

FM

Good

Over: TWELVE MILE CREEK

086152402, Tama, IA

Built 1999 Load: 32.7 t ADT: 44

T53 F AVE

Good

Over: BRANCH BLACK HAWK CREEK

086160102, Tama, IA

Built 2019 Load: 32.7 t ADT: 49

FM

Good

Over: BR FOUR MILE CRK

086163601, Tama, IA

Built 1990 Load: 32.7 t ADT: 20

BROAD STREET

Good

Over: STREAM

083162105, Tama, IA

Built 2006 Load: 32.7 t ADT: 196

US 30

Good

Over: TRIB TO IOWA RIVER

0.7 MI. E OF BUS. US 30, Tama, IA

Built 2008 Load: 32.7 t ADT: 6,500

LOCAL

Good

Over: DEER CREEK

085163206, Tama, IA

Built 1994 Load: 32.7 t ADT: 88

N44 LAKE RD

Good

Over: DRAINAGE DITCH

068330706, Taylor, IA

Built 1988 Load: 32.7 t ADT: 417

N64

Good

Over: SMALL NATURAL STREAM

070322902, Taylor, IA

Built 2004 Load: 32.7 t ADT: 927

LOCAL

Good

Over: TRIB.PLATTE RIVER DITCH

067330201, Taylor, IA

Built 1987 Load: 32.7 t ADT: 10

235TH ST

Good

Over: CREEK

068341303, Taylor, IA

Built 2020 Load: 32.7 t ADT: 20

265TH ST

Good

Over: BRANCH OF BUSHY CREEK

068352603, Taylor, IA

Built 2022 Load: 32.7 t ADT: 40

FM

Good

Over: HOG BRANCH

069321001, Taylor, IA

Built 1988 Load: 32.7 t ADT: 499

170TH ST

Good

Over: MIDDLE RIVER

069330701, Taylor, IA

Built 2012 Load: 32.7 t ADT: 20

120TH ST

Good

Over: EAST RIVER

070321401, Taylor, IA

Built 2022 Load: 32.7 t ADT: 71

FM

Good

Over: EAST RIVER

070322301, Taylor, IA

Built 1990 Load: 32.7 t ADT: 45

FM

Good

Over: MIDDLE BRANCH 102 RIVER

070331001, Taylor, IA

Built 2002 Load: 32.7 t ADT: 60

J20 (130TH ST)

Good

Over: SMALL STREAM

070342101, Taylor, IA

Built 2012 Load: 32.7 t ADT: 309

150TH ST

Good

Over: BRANCH NODAWAY RIVER

070352907, Taylor, IA

Built 2021 Load: 32.7 t ADT: 29

LOCAL RD

Good

Over: STREAM

070323102, Taylor, IA

Built 2004 Load: 32.7 t ADT: 11

FM

Good

Over: TWELVE MILE CREEK

071282705, Union, IA

Built 1977 Load: 32.7 t ADT: 60

LOCAL

Good

Over: STREAM

072281806, Union, IA

Built 1995 Load: 32.7 t ADT: 72

FM POLE RD

Good

Over: MIDDLE PLATTE RIVER

072300806, Union, IA

Built 1993 Load: 32.7 t ADT: 568

LOC W ADAMS ST

Good

Over: STREAM

072311005, Union, IA

Built 2001 Load: 32.7 t ADT: 369

H 17 REA RD

Good

Over: STREAM

073291205, Union, IA

Built 2014 Load: 32.7 t ADT: 170

PHEASANT AVENUE

Good

Over: STREAM

073292202, Union, IA

Built 2022 Load: 32.7 t ADT: 21

H 17 (REA RD)

Good

Over: WEST WOLF CREEK

073281701, Union, IA

Built 2014 Load: 32.7 t ADT: 219

8TH ST RELOC!

Good

Over: DRAINAGE

000000000, Union, IA

Built 1992 Load: 32.7 t ADT: 387

W 2ND STREET

Good

Over: HARROWS CREEK

072141300, Wapello, IA

Built 1977 Load: 32.7 t ADT: 5,800

42ND AVE

Good

Over: CHIPPEWA CREEK

071122100, Wapello, IA

Built 2022 Load: 32.7 t ADT: 47

LOCAL

Good

Over: CHIPPEWA CREEK

071122804, Wapello, IA

Built 2010 Load: 32.7 t ADT: 47

FM

Good

Over: TURKEY CREEK

071131005, Wapello, IA

Built 1988 Load: 32.7 t ADT: 210

FM

Good

Over: SUGAR CREEK

072131603, Wapello, IA

Built 1991 Load: 32.7 t ADT: 850

FM

Good

Over: BRANCH DES MOINES RIVER

072131701, Wapello, IA

Built 2006 Load: 32.7 t ADT: 1,500

FM

Good

Over: SUGAR CREEK

072132941, Wapello, IA

Built 1993 Load: 32.7 t ADT: 550

50TH AVE

Good

Over: BR CEDAR CREEK

072120902, Wapello, IA

Built 2008 Load: 32.7 t ADT: 62

RELOC 110TH

Good

Over: SUGAR CREEK

072132821, Wapello, IA

Built 2005 Load: 32.7 t ADT: 1,370

I-35

Good

Over: DRAINAGE DITCH

5.2 MI. N OF Jct. IA 92, Warren, IA

Built 1957 Load: 32.7 t ADT: 24,700

150TH

Good

Over: TURKEY CREEK

074231602, Warren, IA

Built 2002 Load: 32.7 t ADT: 26

FM

Good

Over: DD

074240304, Warren, IA

Built 2002 Load: 32.7 t ADT: 60

80TH AVE

Good

Over: PAPOOSE CREEK

074240802, Warren, IA

Built 2000 Load: 32.7 t ADT: 89

FM

Good

Over: DD

075220702, Warren, IA

Built 1993 Load: 32.7 t ADT: 1,330

LOCAL ROAD

Good

Over: BRANCH SQUAW CREEK

075242702, Warren, IA

Built 1997 Load: 32.7 t ADT: 103

LOCAL

Good

Over: SHORT CREEK

076232106, Warren, IA

Built 1989 Load: 32.7 t ADT: 587

FM

Good

Over: S RIVER

076232402, Warren, IA

Built 1998 Load: 32.7 t ADT: 79

LOCAL

Good

Over: BRANCH NORTH RIVER

076250403, Warren, IA

Built 2002 Load: 32.7 t ADT: 41

FM

Good

Over: CREEK

077252708, Warren, IA

Built 1998 Load: 32.7 t ADT: 270

CO RD W64

Good

Over: WHISKEY RUN CREEK

076063404, Washington, IA

Built 2006 Load: 32.7 t ADT: 520

Showing 12,151-12,200 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.