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

PIONEER RD

Good

Over: SMALL STREAM

088043405, Delaware, IA

Built 2019 Load: 38.9 t ADT: 49

STEGER RD

Good

Over: STREAM

087021603, Dubuque, IA

Built 2021 Load: 38.9 t ADT: 33

DURANGO RD

Good

Over: CREEK

090e23108, Dubuque, IA

Built 2017 Load: 38.9 t ADT: 314

FLANNAGAN RD

Good

Over: N FORK LITTLE MAQUKETA

9001 15 4050, Dubuque, IA

Built 2016 Load: 38.9 t ADT: 88

H AVE

Good

Over: GUNDLACH CREEK

091081302, Fayette, IA

Built 2023 Load: 38.9 t ADT: 20

30TH ST

Good

Over: E BUFFALO CR

091082801, Fayette, IA

Built 2018 Load: 38.9 t ADT: 39

L AVE

Good

Over: VOLGA RIVER

092082902, Fayette, IA

Built 2021 Load: 38.9 t ADT: 70

180TH ST

Good

Over: N BR VOLGA RIVER

093090801, Fayette, IA

Built 2018 Load: 38.9 t ADT: 39

US 18

Good

Over: HAUGH CREEK

0.4 MI. W OF CR V-68, Fayette, IA

Built 2016 Load: 38.9 t ADT: 2,250

DANCER AVE

Good

Over: ACKLEY CREEK

094181502, Floyd, IA

Built 2011 Load: 38.9 t ADT: 147

280TH ST

Good

Over: ACKLEY CREEK

094182301, Floyd, IA

Built 2015 Load: 38.9 t ADT: 26

S70 BALSAM AVE

Good

Over: FLOOD CREEK

097182002, Floyd, IA

Built 2020 Load: 38.9 t ADT: 560

WARBLER AVE

Good

Over: NORTH BEAVER CREEK

090192601, Franklin, IA

Built 2011 Load: 38.9 t ADT: 35

40TH ST

Good

Over: NORTH BEAVER CREEK

090192701, Franklin, IA

Built 2011 Load: 38.9 t ADT: 35

E57 290TH ST

Good

Over: GREENBRIER CREEK

0.1 Mi E K Ave, Greene, IA

Built 2017 Load: 38.9 t ADT: 131

R AVE

Good

Over: N FORK BLACK HAWK CREEK

089163602, Grundy, IA

Built 2022 Load: 38.9 t ADT: 39

225TH ST

Good

Over: DRAINAGE DITCH 97

096263403, Hancock, IA

Built 2022 Load: 38.9 t ADT: 315

D55 290TH ST

Good

Over: DRAINAGE

086191201, Hardin, IA

Built 2017 Load: 38.9 t ADT: 25

FM

Good

Over: DOUD CREEK

086193605, Hardin, IA

Built 2010 Load: 38.9 t ADT: 697

260TH ST

Good

Over: BEAR CREEK

087192601, Hardin, IA

Built 2017 Load: 38.9 t ADT: 21

FM-ROBIN AVE

Good

Over: STREAM

097121202, Howard, IA

Built 2010 Load: 38.9 t ADT: 69

V46 (ROBIN AVE)

Good

Over: TURKEY RIVER

097121302, Howard, IA

Built 2013 Load: 38.9 t ADT: 69

FM DOUGLAS AVE

Good

Over: LITTLE WAPSIPINICON

098141004, Howard, IA

Built 2011 Load: 38.9 t ADT: 39

D15 130TH ST

Good

Over: ASHTON CREEK

089401901, Ida, IA

Built 2013 Load: 38.9 t ADT: 210

60TH AVE

Good

Over: MILL CREEK

083013204, Jones, IA

Built 1981 Load: 38.9 t ADT: 34

98TH ST

Good

Over: LITTLE BEAR CREEK

084022403, Jones, IA

Built 2012 Load: 38.9 t ADT: 21

BUFFALO ROAD

Good

Over: DRAINAGE

084040303, Jones, IA

Built 2022 Load: 38.9 t ADT: 442

105TH AVE

Good

Over: MINERAL CREEK

085023304, Jones, IA

Built 2017 Load: 38.9 t ADT: 20

P66 (220TH AVE)

Good

Over: PRAIRIE CREEK

095273407, Kossuth, IA

Built 2012 Load: 38.9 t ADT: 50

B 30 (250TH ST)

Good

Over: LOTTS CREEK

096302140, Kossuth, IA

Built 2012 Load: 38.9 t ADT: 90

FM 330TH ST

Good

Over: BUFFALO CREEK

097270960, Kossuth, IA

Built 2013 Load: 38.9 t ADT: 609

P30 90TH AVE

Good

Over: CALAMUS CREEK

097293302, Kossuth, IA

Built 2018 Load: 38.9 t ADT: 339

LOC 30TH AVE

Good

Over: BLACK CAT CREEK

097300902, Kossuth, IA

Built 2009 Load: 38.9 t ADT: 30

230TH AVE

Good

Over: MIDDLE BRANCH BLUE EARTH

099271101, Kossuth, IA

Built 2023 Load: 38.9 t ADT: 11

FM 500TH ST

Good

Over: MIDDLE BRANCH BLUE EARTH

100281301, Kossuth, IA

Built 2011 Load: 38.9 t ADT: 150

US 151

Good

Over: DRAINAGE DITCH #2

0.6 MI. SOUTH OF US 30, Linn, IA

Built 2020 Load: 38.9 t ADT: 9,900

BUCHANAN AVE

Good

Over: KLONDIKE CREEK

099481202, Lyon, IA

Built 2019 Load: 38.9 t ADT: 26

W DAKTOA AVE

Good

Over: RIO GRANDE CREEK

098440201, Lyon, IA

Built 2011 Load: 38.9 t ADT: 1,349

LOCAL RD

Good

Over: GRAND RIVER

074290802, Madison, IA

Built 1992 Load: 38.9 t ADT: 50

LOCAL

Good

Over: STREAM

077192903, Marion, IA

Built 2010 Load: 38.9 t ADT: 73

280TH ST

Good

Over: BIG WHISKEY CREEK

9045040110, Plymouth, IA

Built 2010 Load: 38.9 t ADT: 34

270TH ST

Good

Over: BIG WHISKEY CREEK

9145330110, Plymouth, IA

Built 2016 Load: 38.9 t ADT: 26

I-80 EB RAMP D

Good

Over: DRAINAGE

0.2 MILE EAST OF US 69, Polk, IA

Built 1999 Load: 38.9 t ADT: 2,300

250TH ST

Good

Over: CREEK

079E50801, Scott, IA

Built 2013 Load: 38.9 t ADT: 40

FM

Good

Over: SMALL

095 44 19 01, Sioux, IA

Built 2009 Load: 38.9 t ADT: 60

LOCAL

Good

Over: SM STREAM

097462702, Sioux, IA

Built 2011 Load: 38.9 t ADT: 240

660TH AVE

Good

Over: DD 81 RICHLAND

0.23 Mi S of 190th St/E29, Story, IA

Built 2016 Load: 38.9 t ADT: 45

220TH ST

Good

Over: BRANCH SALT CREEK

084130401, Tama, IA

Built 2022 Load: 38.9 t ADT: 29

270TH ST

Good

Over: SUGAR CREEK

084163203, Tama, IA

Built 2013 Load: 38.9 t ADT: 44

P 33 (POLE RD)

Good

Over: EAST PLATTE RIVER

071301702, Union, IA

Built 2012 Load: 38.9 t ADT: 120

Showing 13,901-13,950 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.