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 RD F32

Good

Over: LYONS CREEK

080381904, Shelby, IA

Built 2002 Load: 69.0 t ADT: 608

OUTER DRIVE

Good

Over: FLOYD RIVER & CNIC RR

0894714, Woodbury, IA

Built 2009 Load: 69.2 t ADT: 14,264

J 5T

Good

Over: DRAINAGE

070170801, Appanoose, IA

Built 2016 Load: 69.3 t ADT: 990

LOCAL

Good

Over: MUD CREEK

084100602, Benton, IA

Built 1998 Load: 69.4 t ADT: 40

ROCKWOOD AVE

Good

Over: CREEK

068331302, Taylor, IA

Built 2019 Load: 69.7 t ADT: 26

LOCAL

Good

Over: SMALL CREEK

072181125, Monroe, IA

Built 2003 Load: 70.3 t ADT: 20

270TH STREET

Good

Over: SMALL STREAM

081E13301, Clinton, IA

Built 2018 Load: 70.6 t ADT: 21

R46 PLEASANTON RD

Good

Over: SMALL STREAM

067251004, Decatur, IA

Built 2017 Load: 70.6 t ADT: 110

J35 200TH ST

Good

Over: STREAM

069342801, Taylor, IA

Built 2020 Load: 70.6 t ADT: 329

EVERGREEN RD

Good

Over: VOLGA RIVER

092052206, Clayton, IA

Built 1995 Load: 70.7 t ADT: 88

29 AVE

Good

Over: BR LITTLE BEAR CREEK

083090504, Benton, IA

Built 2000 Load: 71.3 t ADT: 11

GREENHILL RD

Good

Over: DRY RUN CREEK

000000000, Black Hawk, IA

Built 1990 Load: 71.3 t ADT: 5,994

110TH ST

Good

Over: CREEK

083E21103, Clinton, IA

Built 2011 Load: 71.3 t ADT: 113

FM

Good

Over: CREEK

087432310, Woodbury, IA

Built 2004 Load: 71.4 t ADT: 120

220TH AVE

Good

Over: CREEK

082E33002, Clinton, IA

Built 2020 Load: 71.9 t ADT: 62

FAIRVIEW ROAD

Good

Over: SMALL CREEK

077353501, Cass, IA

Built 2022 Load: 72.9 t ADT: 46

LINDEN AVE

Good

Over: SOUTH CHARITON

069223401, Wayne, IA

Built 2017 Load: 73.3 t ADT: 26

US 30

Good

Over: NORTH RACCOON RIVER

3.8 Mi. W of IA 4, Greene, IA

Built 2010 Load: 73.6 t ADT: 3,270

MM AVE

Good

Over: SMALL STREAM

080101804, Iowa, IA

Built 2023 Load: 73.6 t ADT: 46

240TH AVE

Good

Over: STREAM

075182502, Marion, IA

Built 2017 Load: 73.9 t ADT: 47

FM - 695TH ST

Good

Over: DRAINAGE

073162004, Monroe, IA

Built 2000 Load: 74.8 t ADT: 25

197TH ST

Good

Over: STREAM

072282307, Union, IA

Built 2017 Load: 74.8 t ADT: 15

KNOX RD

Good

Over: COOPER CREEK

069423203, Fremont, IA

Built 2013 Load: 76.2 t ADT: 450

260TH ST

Good

Over: SMALL STREAM

081E22601, Clinton, IA

Built 2006 Load: 77.1 t ADT: 11

Y 44 170TH AVE

Good

Over: SMALL STREAM

082E22902, Clinton, IA

Built 2013 Load: 77.1 t ADT: 470

E 57 265TH ST

Good

Over: SKUNK RIVER

083233006, Story, IA

Built 2005 Load: 78.0 t ADT: 50

LOWER W BR RD

Good

Over: WAPSINONOC CR

T79N,R05W, Section 11, Johnson, IA

Built 2017 Load: 79.1 t ADT: 120

70TH ST.

Good

Over: SMALL STREAM

083040601, Jones, IA

Built 1988 Load: 79.7 t ADT: 41

160TH ST

Good

Over: DRAINAGE

082E10102, Clinton, IA

Built 2020 Load: 80.0 t ADT: 30

160TH ST

Good

Over: WILLIAMS CREEK

082E404001, Clinton, IA

Built 2018 Load: 80.4 t ADT: 21

VICTOR AVE

Good

Over: S FORK MAQUOKETA RIVER

9007100059, Buchanan, IA

Built 2016 Load: 80.7 t ADT: 41

130TH ST

Good

Over: HUNTER CREEK

9009198800, Buchanan, IA

Built 2016 Load: 80.7 t ADT: 15

205TH ST

Good

Over: CREEK

082E42903, Clinton, IA

Built 2019 Load: 80.7 t ADT: 35

145TH ST

Good

Over: SMALL CREEK

083E32503, Clinton, IA

Built 2005 Load: 80.7 t ADT: 40

LCL-COMPASS AVE

Good

Over: STREAM

073411403, Mills, IA

Built 2000 Load: 82.9 t ADT: 11

LOCAL

Good

Over: DD #17 JACK CREEK

098321601, Emmet, IA

Built 1977 Load: 83.6 t ADT: 5

IA 2

Good

Over: STREAM

0.8 mi. E of E Jct IA 148, Taylor, IA

Built 1978 Load: 86.8 t ADT: 1,450

LOCAL

Good

Over: BRANCH NODAWAY RIVER

077332901, Adair, IA

Built 2003 Load: 87.3 t ADT: 29

RANCH RD

Good

Over: CREEK

00000, Winneshiek, IA

Built 2011 Load: 88.0 t ADT: 39

Z40 400TH AVE

Good

Over: SOUTH BRANCH ELK RIVER

083E63006, Clinton, IA

Built 2016 Load: 88.8 t ADT: 45

345TH AVENUE

Good

Over: CREEK

000000000, Clinton, IA

Built 2010 Load: 88.9 t ADT: 62

VIKING RD

Good

Over: TRIB TO BEAVER CREEK

89-14-31-01-10, Black Hawk, IA

Built 2003 Load: 89.4 t ADT: 59

MONASTARY RD

Good

Over: CATFISH CREEK

000000000, Dubuque, IA

Built 2010 Load: 89.7 t ADT: 1,160

210TH ST

Good

Over: CREEK

082E23101, Clinton, IA

Built 2010 Load: 89.8 t ADT: 41

185TH ST

Good

Over: CREEK

T82E518, Clinton, IA

Built 2010 Load: 89.8 t ADT: 26

LOCAL (LWC)

Good

Over: BR PRAIRIE CREEK

082091902, Benton, IA

Built 1996 Load: 89.9 t ADT: 20

140TH AVE

Good

Over: PIKE RUN

099241602, Winnebago, IA

Built 2019 Load: 90.1 t ADT: 26

60TH AVE

Good

Over: HAWK RUN CREEK

075210102, Marion, IA

Built 2011 Load: 90.2 t ADT: 21

IA 175

Good

Over: ROBERTS CREEK

0.6 MILE WEST OF SR D41, Hardin, IA

Built 1972 Load: 90.5 t ADT: 1,670

IA 48

Good

Over: COE CREEK

0.8 mi. W of Jct. SR H-14, Montgomery, IA

Built 1974 Load: 90.5 t ADT: 1,210

Showing 16,401-16,450 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.