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

160TH AVE

Good

Over: HONEY CREEK

070180602, Appanoose, IA

Built 2020 Load: 35.0 t ADT: 41

N ELK RUN RD

Good

Over: TRIB TO ELK RUN CREEK

89-12-03-02-10, Black Hawk, IA

Built 1974 Load: 35.0 t ADT: 1,463

QUONSET AVE

Good

Over: DRAINAGE

.5 mi. north of 325th st., Buchanan, IA

Built 2015 Load: 35.0 t ADT: 51

FM

Good

Over: NORTH RACOON

084330303, Carroll, IA

Built 1989 Load: 35.0 t ADT: 100

FM J AVE.

Good

Over: ROCK CREEK

091411502, Cherokee, IA

Built 2011 Load: 35.0 t ADT: 15

372ND AVENUE

Good

Over: CREEK

082E50304, Clinton, IA

Built 2021 Load: 35.0 t ADT: 82

FM

Good

Over: CREEK

088E20906, Dubuque, IA

Built 2006 Load: 35.0 t ADT: 450

220TH ST

Good

Over: SMALL STREAM

220th St., West Union, IA, Fayette, IA

Built 2016 Load: 35.0 t ADT: 440

T AVE

Good

Over: TRIB TO VOLGA RIVER

093102407, Fayette, IA

Built 2015 Load: 35.0 t ADT: 78

T47 Q AVE

Good

Over: MOSQUITO CREEK

087163402, Grundy, IA

Built 2022 Load: 35.0 t ADT: 628

LOCAL

Good

Over: SMALL UN-NAMED CREEK

096390301, O'Brien, IA

Built 1991 Load: 35.0 t ADT: 11

100TH ST

Good

Over: OCHEYEDAN RIVER

100th St ov WBr Ocheyedan, Osceola, IA

Built 2019 Load: 35.0 t ADT: 60

W GARFIELD ST

Good

Over: CRYSTAL CREEK

000000000, Scott, IA

Built 2000 Load: 35.0 t ADT: 81

LOCAL

Good

Over: W. NISHNABOTNA RIVER

079380807, Shelby, IA

Built 2004 Load: 35.0 t ADT: 113

WASHINGTON AVE

Good

Over: CAMP CREEK

077073204, Washington, IA

Built 2018 Load: 35.0 t ADT: 40

380TH ST

Good

Over: BUTTRICK CREEK

086292801, Webster, IA

Built 2014 Load: 35.0 t ADT: 81

260TH ST

Good

Over: STREAM

087442803, Woodbury, IA

Built 2021 Load: 35.0 t ADT: 26

250TH STREET

Good

Over: LIZARD CREEK

081E12001, Clinton, IA

Built 2004 Load: 35.1 t ADT: 82

320TH AVE

Good

Over: SUGAR CREEK

083E40304, Clinton, IA

Built 2003 Load: 35.1 t ADT: 11

242 TRAIL

Good

Over: WILLOW CREEK

079431503, Harrison, IA

Built 1986 Load: 35.1 t ADT: 60

SOUTH RIDGE RD

Good

Over: PERRY CREEK

090473303, Plymouth, IA

Built 1978 Load: 35.1 t ADT: 518

IA 60 NB

Good

Over: LITTLE FLOYD RIVER

0.4 mi. S of Jct. SR L26, Sioux, IA

Built 2005 Load: 35.1 t ADT: 3,250

IA 60 SB

Good

Over: LITTLE FLOYD RIVER

0.4 mi. S of SR L26, Sioux, IA

Built 2006 Load: 35.1 t ADT: 3,250

LOCAL

Good

Over: BRUSHY FORK CREEK

082340701, Carroll, IA

Built 1994 Load: 35.2 t ADT: 29

SW MAIER AVE

Good

Over: OLD MANS CREEK

078060604, Johnson, IA

Built 1996 Load: 35.2 t ADT: 140

FM SW 500TH ST

Good

Over: OLD MANS CREEK

078061603, Johnson, IA

Built 1996 Load: 35.2 t ADT: 510

ROHRET RD

Good

Over: N FORK OLD MAN CREEK

079082601, Johnson, IA

Built 1979 Load: 35.2 t ADT: 30

US 151 NB

Good

Over: W BRANCH OF KITTY CREEK

0.5 MI. S OF JCT. IA 38, Jones, IA

Built 2003 Load: 35.2 t ADT: 4,400

LOC 320TH ST

Good

Over: CALAMUS CREEK

097291801, Kossuth, IA

Built 1991 Load: 35.2 t ADT: 15

SB US 61

Good

Over: BNSF RR

3.1 mi. S of Jct. IA 2, Lee, IA

Built 1999 Load: 35.2 t ADT: 3,400

FM

Good

Over: OTTER CREEK

098423102, Osceola, IA

Built 1994 Load: 35.2 t ADT: 110

L 14

Good

Over: OTTER CREEK

097440102, Sioux, IA

Built 1991 Load: 35.2 t ADT: 1,267

LOCAL RD

Good

Over: STREAM

071280702, Union, IA

Built 2009 Load: 35.2 t ADT: 62

CHERRY ST

Good

Over: E BR MIDDLE PLATTE RIVER

072303102, Union, IA

Built 2023 Load: 35.2 t ADT: 62

LOCAL ROAD

Good

Over: WEST CREEK

074241503, Warren, IA

Built 2009 Load: 35.2 t ADT: 21

FM

Good

Over: NORTH RIVER

077252712, Warren, IA

Built 1998 Load: 35.2 t ADT: 170

NB US 218

Good

Over: GOOSE CREEK

6.6 MI. N OF JCT. IA 92, Washington, IA

Built 1994 Load: 35.2 t ADT: 7,450

V44 16 AVE

Good

Over: PRAIRIE CREEK

082110602, Benton, IA

Built 2021 Load: 35.3 t ADT: 570

E 44 (70TH ST)

Good

Over: PRAIRIE CREEK

083111603, Benton, IA

Built 2013 Load: 35.3 t ADT: 1,070

FM

Good

Over: ROCK CREEK

085120602, Benton, IA

Built 2006 Load: 35.3 t ADT: 1,340

FM

Good

Over: BLUE CREEK

086092602, Benton, IA

Built 2016 Load: 35.3 t ADT: 69

BRANDON RD

Good

Over: WOLF CREEK

87-11-19-04-10, Black Hawk, IA

Built 2012 Load: 35.3 t ADT: 1,542

M 50 160TH AVE

Good

Over: OUTLET CREEK

090362702, Buena Vista, IA

Built 2017 Load: 35.3 t ADT: 509

LOCAL

Good

Over: BEAVER CREEK

090182301, Butler, IA

Built 1989 Load: 35.3 t ADT: 30

LOCAL - PELLA

Good

Over: WATERWAY

075342101, Cass, IA

Built 2007 Load: 35.3 t ADT: 15

LOCAL - QUIMBY

Good

Over: NISHNABOTNA RIVER

075373003, Cass, IA

Built 2007 Load: 35.3 t ADT: 100

FM 190TH AVE

Good

Over: OCHEYEDAN RIVER

096371502, Clay, IA

Built 2002 Load: 35.3 t ADT: 1,277

410TH AVE.

Good

Over: HARTS MILL CREEK

082E62902, Clinton, IA

Built 1995 Load: 35.3 t ADT: 21

FM

Good

Over: BOYER RIVER

082400803, Crawford, IA

Built 1994 Load: 35.3 t ADT: 249

FM

Good

Over: TRIB. N. FABIUS CREEK

068153310, Davis, IA

Built 1999 Load: 35.3 t ADT: 20

Showing 12,851-12,900 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.