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

NB US 61

Good

Over: DRAINAGE

6.7 MI. N OF N JCT. US 30, Clinton, IA

Built 1996 Load: 32.3 t ADT: 4,600

SB US 61

Good

Over: DRAINAGE

6.7 MI. N OF N JCT. US 30, Clinton, IA

Built 1996 Load: 32.3 t ADT: 4,600

NB US 61

Good

Over: SILVER CREEK

6.4 MI. S OF JCT. IA 136, Clinton, IA

Built 1996 Load: 32.3 t ADT: 4,600

NB US 61

Good

Over: DEEP CREEK

3.3 MI. S OF JCT. IA 136, Clinton, IA

Built 1996 Load: 32.3 t ADT: 4,400

LAKE WAPELLO SP

Good

Over: PEE DEE CREEK

2.2 MI. N of Jct. SR J3T, Davis, IA

Built 1994 Load: 32.3 t

I AVE.

Good

Over: SMALL STREAM

092083501, Fayette, IA

Built 1990 Load: 32.3 t ADT: 33

400 AVENUE

Good

Over: WALNUT CREEK

070402602, Fremont, IA

Built 1987 Load: 32.3 t ADT: 11

WB US 20

Good

Over: OVER UP RR

1.5 MILES EAST OF SR S27, Hardin, IA

Built 1990 Load: 32.3 t ADT: 4,650

SW NAPLES AVE

Good

Over: BR OLD MAN CR

078060802, Johnson, IA

Built 1997 Load: 32.3 t ADT: 102

SW EAGLE AVENUE

Good

Over: F OLD MANS CREEK

079081004, Johnson, IA

Built 2002 Load: 32.3 t ADT: 51

1ST AVENUE

Good

Over: MUDDY CREEK

080063204, Johnson, IA

Built 1988 Load: 32.3 t ADT: 6,625

FM

Good

Over: DRY RUN

098392701, Osceola, IA

Built 1971 Load: 32.3 t ADT: 45

LOCAL

Good

Over: STREAM

098403401, Osceola, IA

Built 1976 Load: 32.3 t ADT: 15

TAFT AVE

Good

Over: STREAM

098403402, Osceola, IA

Built 1976 Load: 32.3 t ADT: 21

FM

Good

Over: DRY RUN

098411201, Osceola, IA

Built 1966 Load: 32.3 t ADT: 758

FM

Good

Over: WAGNER CREEK

098420104, Osceola, IA

Built 2006 Load: 32.3 t ADT: 60

FM

Good

Over: DRY RUN

098422901, Osceola, IA

Built 1972 Load: 32.3 t ADT: 60

FM

Good

Over: RUSH LAKE OUTLET

099401106, Osceola, IA

Built 1984 Load: 32.3 t ADT: 1,037

FM

Good

Over: DRY RUN

099412001, Osceola, IA

Built 1972 Load: 32.3 t ADT: 439

FM

Good

Over: DRY RUN

099413301, Osceola, IA

Built 1959 Load: 32.3 t ADT: 110

LOCAL

Good

Over: SMALL STREAM

099421201, Osceola, IA

Built 1979 Load: 32.3 t ADT: 30

LOCAL

Good

Over: STREAM

100391601, Osceola, IA

Built 1934 Load: 32.3 t ADT: 21

NB I-35,EB I-80

Good

Over: DES MOINES RVR BIKE PATH

1.6 MI. E OF JCT. IA 28, Polk, IA

Built 1958 Load: 32.3 t ADT: 48,000

FM

Good

Over: FOURMILE CREEK

079232013, Polk, IA

Built 1981 Load: 32.3 t ADT: 6,573

FM RD M56

Good

Over: EAST BR WEST NISHNABOTNA

080372702, Shelby, IA

Built 1986 Load: 32.3 t ADT: 29

LOCAL

Good

Over: SMALL STREAM

094433001, Sioux, IA

Built 1996 Load: 32.3 t ADT: 11

LOCAL

Good

Over: STREAM

069230201, Wayne, IA

Built 2002 Load: 32.3 t ADT: 50

EASTERN AVE

Good

Over: BUTTRICK CREEK

086300202, Webster, IA

Built 2000 Load: 32.3 t ADT: 50

LOCAL

Good

Over: BUTTRICK CREEK

086302702, Webster, IA

Built 1997 Load: 32.3 t ADT: 30

FM

Good

Over: HOLIDAY CREEK

088280304, Webster, IA

Built 2000 Load: 32.3 t ADT: 30

LOCAL

Good

Over: BADGER CREEK

090282003, Webster, IA

Built 2001 Load: 32.3 t ADT: 46

380TH

Good

Over: STREAM

098191806, Worth, IA

Built 1990 Load: 32.3 t ADT: 5

H54 260TH ST

Good

Over: BNSF RR

071351905, Adams, IA

Built 2017 Load: 32.4 t ADT: 439

FM-150TH STREET

Good

Over: E FORK E NODAWAY RIVER

733332, Adams, IA

Built 2008 Load: 32.4 t ADT: 399

FM

Good

Over: YELLOW RIVER

096060205, Allamakee, IA

Built 2010 Load: 32.4 t ADT: 100

WILLIAMS CRK RD

Good

Over: WILLIAMS CREEK

T96NR06W14SE, Allamakee, IA

Built 2015 Load: 32.4 t ADT: 49

GREEN VALLEY RD

Good

Over: VILLAGE CREEK

098051904, Allamakee, IA

Built 2018 Load: 32.4 t ADT: 200

J59 290TH AVE

Good

Over: DRAINAGE DITCH

067161706, Appanoose, IA

Built 2017 Load: 32.4 t ADT: 35

S74 (155TH AVE)

Good

Over: SHOAL CREEK

067191208, Appanoose, IA

Built 2012 Load: 32.4 t ADT: 30

DEWEY RD

Good

Over: STREAM

068171001, Appanoose, IA

Built 2013 Load: 32.4 t ADT: 73

437TH ST

Good

Over: SMALL STREAM

070162203, Appanoose, IA

Built 2018 Load: 32.4 t ADT: 35

US 218

Good

Over: WILDCAT CREEK

2.0 mi. N of jct SR E44, Benton, IA

Built 2016 Load: 32.4 t ADT: 2,690

75TH ST

Good

Over: BRANCH PRAIRIE CREEK

082091101, Benton, IA

Built 2021 Load: 32.4 t ADT: 46

V56 19TH AVE

Good

Over: PRAIRIE CREEK

082111502, Benton, IA

Built 2015 Load: 32.4 t ADT: 157

LOCAL

Good

Over: PRAIRIE CK

082111601, Benton, IA

Built 2016 Load: 32.4 t ADT: 15

30TH AVE

Good

Over: BEAR CREEK

083090402, Benton, IA

Built 2018 Load: 32.4 t ADT: 26

V56 19TH AVE

Good

Over: PRAIRIE CREEK

083113402, Benton, IA

Built 2014 Load: 32.4 t ADT: 44

E44 70TH ST

Good

Over: PRAIRIE CREEK

083121401, Benton, IA

Built 2018 Load: 32.4 t ADT: 481

62ND ST

Good

Over: BRANCH OPOSSUM CREEK

085093305, Benton, IA

Built 2019 Load: 32.4 t ADT: 49

19TH AVE

Good

Over: HINKLE CREEK

085112704, Benton, IA

Built 2014 Load: 32.4 t ADT: 59

Showing 10,351-10,400 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.