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

LOG AVENUE

Good

Over: WEST RAT CREEK

098431102, Lyon, IA

Built 2020 Load: 32.4 t ADT: 41

LOCAL

Good

Over: ALLEN CREEK

098432002, Lyon, IA

Built 1989 Load: 32.4 t ADT: 21

250TH ST

Good

Over: ALLEN CREEK

098433001, Lyon, IA

Built 2017 Load: 32.4 t ADT: 30

MARSH AVE

Good

Over: LITTLE OTTER CREEK

098433602, Lyon, IA

Built 2019 Load: 32.4 t ADT: 71

JEFFERSON AVE

Good

Over: SMALL STREAM

098442302, Lyon, IA

Built 2014 Load: 32.4 t ADT: 46

A52 260TH ST

Good

Over: OTTER CREEK

098443401, Lyon, IA

Built 2020 Load: 32.4 t ADT: 649

HARRISON AVE

Good

Over: BURR OAK CREEK

098453402, Lyon, IA

Built 2019 Load: 32.4 t ADT: 50

IBEX AVE

Good

Over: BURR OAK CREEK

098453602, Lyon, IA

Built 2019 Load: 32.4 t ADT: 50

FIG AVE

Good

Over: LIZARD CREEK

0984622702, Lyon, IA

Built 2014 Load: 32.4 t ADT: 46

K42 GARFIELD AVE

Good

Over: LITTLE ROCK RIVER

098463602, Lyon, IA

Built 2011 Load: 32.4 t ADT: 1,087

210TH ST

Good

Over: PLUM CREEK

098470601, Lyon, IA

Built 2013 Load: 32.4 t ADT: 50

DOGWOOD AVE

Good

Over: OVERFLOW

098473602, Lyon, IA

Built 2019 Load: 32.4 t ADT: 30

220TH ST

Good

Over: PLUM CREEK

098480504, Lyon, IA

Built 2021 Load: 32.4 t ADT: 46

230TH ST

Good

Over: MCLAREN CREEK

098481301, Lyon, IA

Built 2014 Load: 32.4 t ADT: 72

230TH ST

Good

Over: MCLAREN CREEK

098481401, Lyon, IA

Built 2014 Load: 32.4 t ADT: 72

ABLE BLVD

Good

Over: MCLAREN CREEK

0984815, Lyon, IA

Built 2016 Load: 32.4 t ADT: 62

255TH ST

Good

Over: SMALL STREAM

098483003, Lyon, IA

Built 2022 Load: 32.4 t ADT: 30

LOG AVE

Good

Over: HESS CREEK

099432602, Lyon, IA

Built 2015 Load: 32.4 t ADT: 41

200TH ST

Good

Over: TAFT CREEK

099433301, Lyon, IA

Built 2014 Load: 32.4 t ADT: 45

200TH ST

Good

Over: HESS CREEK

099433401, Lyon, IA

Built 2015 Load: 32.4 t ADT: 26

LOCAL ROAD

Good

Over: EMERY CREEK

099441602, Lyon, IA

Built 1994 Load: 32.4 t ADT: 30

LOCAL ROAD

Good

Over: JOHNSON CREEK

099442701, Lyon, IA

Built 1995 Load: 32.4 t ADT: 50

200TH ST

Good

Over: JOHNSON CREEK

099443301, Lyon, IA

Built 2014 Load: 32.4 t ADT: 30

LOCAL ROAD

Good

Over: KLONDIKE CREEK

099470601, Lyon, IA

Built 1991 Load: 32.4 t ADT: 50

DOGWOOD AVE

Good

Over: SMALL STREAM

099471302, Lyon, IA

Built 2015 Load: 32.4 t ADT: 26

160TH ST

Good

Over: BURNS CREEK

099481201, Lyon, IA

Built 2017 Load: 32.4 t ADT: 41

BUCHANAN AVE

Good

Over: KLONDIKE CREEK

099481202, Lyon, IA

Built 2019 Load: 32.4 t ADT: 26

BUCHANAN AVE

Good

Over: KLONDIKE CREEK

099481202, Lyon, IA

Built 2019 Load: 32.4 t ADT: 26

BUCHANAN AVE

Good

Over: KLONDIKE CREEK

099481202, Lyon, IA

Built 2018 Load: 32.4 t ADT: 26

LARCH AVE

Good

Over: TOM CREEK

100432102, Lyon, IA

Built 2017 Load: 32.4 t ADT: 21

JACKSON AVE

Good

Over: TOM CREEK

100442102, Lyon, IA

Built 2017 Load: 32.4 t ADT: 50

K60 INDIAN AVE

Good

Over: TOM CREEK

100443002, Lyon, IA

Built 2022 Load: 32.4 t ADT: 279

LOCAL ROAD

Good

Over: KANARANZI CREEK

100451103, Lyon, IA

Built 2010 Load: 32.4 t ADT: 62

140TH ST

Good

Over: TOM CREEK

100453601, Lyon, IA

Built 2017 Load: 32.4 t ADT: 33

110TH ST

Good

Over: TOOLE CREEK

100461801, Lyon, IA

Built 2017 Load: 32.4 t ADT: 72

CHERRY AVE

Good

Over: SMALL STREAM

100470702, Lyon, IA

Built 2015 Load: 32.4 t ADT: 30

LOCAL ROAD

Good

Over: SMALL STREAM

100472502, Lyon, IA

Built 1994 Load: 32.4 t ADT: 50

LOCAL ROAD

Good

Over: CREEK

099451302, Lyon, IA

Built 1990 Load: 32.4 t ADT: 26

LOCAL ROAD

Good

Over: CREEK

100433102, Lyon, IA

Built 1989 Load: 32.4 t ADT: 35

COOLIDGE AVE

Good

Over: SMALL

098470302, Lyon, IA

Built 1993 Load: 32.4 t ADT: 100

LOCAL

Good

Over: SMALL

100433102, Lyon, IA

Built 1989 Load: 32.4 t ADT: 35

140TH ST

Good

Over: CREEK

100443601, Lyon, IA

Built 1989 Load: 32.4 t ADT: 30

JAY AVE

Good

Over: STREAM

098442202, Lyon, IA

Built 2013 Load: 32.4 t ADT: 15

DOGWOOD AVE

Good

Over: SMALL STREAM

100472402, Lyon, IA

Built 2015 Load: 32.4 t ADT: 50

G61 MACKSBURG RD

Good

Over: WATERWAY

074281703, Madison, IA

Built 2019 Load: 32.4 t ADT: 477

LARKSPUR AVE

Good

Over: S FORK CLANTON CREEK

074283602, Madison, IA

Built 2016 Load: 32.4 t ADT: 50

VALLEYVIEW AVE

Good

Over: DRAINAGE

075261004, Madison, IA

Built 2021 Load: 32.4 t ADT: 45

TIMBER RIDGE AVE

Good

Over: BADGER CREEK

077262004, Madison, IA

Built 2015 Load: 32.4 t ADT: 50

HERITAGE AVE

Good

Over: N BRANCH NORTH RIVER

077281704, Madison, IA

Built 2018 Load: 32.4 t ADT: 29

COTTONWOOD AVE

Good

Over: N BR NORTH RIVER

077290402, Madison, IA

Built 2019 Load: 32.4 t ADT: 34

Showing 10,801-10,850 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.