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

L48 J AVE

Good

Over: BEAR CREEK

093413402, Cherokee, IA

Built 2017 Load: 33.0 t ADT: 489

V AVENUE

Good

Over: PITCHER CREEK

091391502, Cherokee, IA

Built 2022 Load: 33.0 t ADT: 60

120TH AVE

Good

Over: WILLOW CREEK

00000, Clay, IA

Built 2011 Load: 33.0 t ADT: 11

400TH ST

Good

Over: WILLOW CREEK

95381701, Clay, IA

Built 2011 Load: 33.0 t ADT: 11

Y4E 130TH AVE

Good

Over: OVERFLOW STRUCTURE

081E11507, Clinton, IA

Built 2014 Load: 33.0 t ADT: 1,060

G AVE

Good

Over: BIG CREEK

084390301, Crawford, IA

Built 2018 Load: 33.0 t ADT: 26

200TH AVE

Good

Over: HONEY CREEK

089050204, Delaware, IA

Built 1983 Load: 33.0 t ADT: 29

URBAIN RD

Good

Over: CREEK

087E10607, Dubuque, IA

Built 2018 Load: 33.0 t ADT: 15

W AVE

Good

Over: CREEK

093103302, Fayette, IA

Built 1981 Load: 33.0 t ADT: 766

30TH ST

Good

Over: DRAINAGE DITCH NO 13

90193501102500, Franklin, IA

Built 2020 Load: 33.0 t ADT: 59

MCMURRAY AVE

Good

Over: KEIGLEY BRANCH

086252302, Hamilton, IA

Built 2017 Load: 33.0 t ADT: 34

LOCAL

Good

Over: BRUSH CREEK

072082604, Jefferson, IA

Built 1981 Load: 33.0 t ADT: 80

FOREST CHAPEL

Good

Over: DUTCH CREEK

084041516, Jones, IA

Built 1995 Load: 33.0 t ADT: 304

G63 305TH ST

Good

Over: DRAINAGE

074151303, Mahaska, IA

Built 2016 Load: 33.0 t ADT: 120

80TH AVE

Good

Over: TRACEY CREEK

075203202, Marion, IA

Built 2020 Load: 33.0 t ADT: 51

NOBLE AVE

Good

Over: BURR OAK CREEK

099163202, Mitchell, IA

Built 1973 Load: 33.0 t ADT: 79

LOCAL RD

Good

Over: SOUTH LIZARD CREEK

090320601, Pocahontas, IA

Built 1979 Load: 33.0 t ADT: 11

CHAYSE ST SW

Good

Over: DITCH NUMBER 2

080233600, Polk, IA

Built 2021 Load: 33.0 t ADT: 14

EASTERN HILLS DR

Good

Over: STREAM

150' NE State Orchard Rd, Pottawattamie, IA

Built 2020 Load: 33.0 t ADT: 3,339

310TH AVE

Good

Over: STREAM

067281502, Ringgold, IA

Built 2017 Load: 33.0 t ADT: 5

FM

Good

Over: NO NAME

094432002, Sioux, IA

Built 1974 Load: 33.0 t ADT: 722

L22

Good

Over: WILLOW CREEK

095432602, Sioux, IA

Built 1955 Load: 33.0 t ADT: 359

FM

Good

Over: CREEK

095443501, Sioux, IA

Built 1968 Load: 33.0 t ADT: 71

FM

Good

Over: NO NAME

095462101, Sioux, IA

Built 1974 Load: 33.0 t ADT: 898

FM

Good

Over: NO NAME CREEK

095471502, Sioux, IA

Built 1973 Load: 33.0 t ADT: 369

LOCAL

Good

Over: SMALL STREAM

097452703, Sioux, IA

Built 1960 Load: 33.0 t ADT: 1,117

FM

Good

Over: SMALL CREEK

097472902, Sioux, IA

Built 1976 Load: 33.0 t ADT: 718

TROUT RUN RD

Good

Over: SMALL STREAM

0.2 Mi E Middle Calmar Rd, Winneshiek, IA

Built 2016 Load: 33.0 t ADT: 805

FM

Good

Over: BUCK CREEK

078362802, Audubon, IA

Built 1973 Load: 33.1 t ADT: 110

WEIDEN RD

Good

Over: SINK CREEK

88-12-17-06-10, Black Hawk, IA

Built 1985 Load: 33.1 t ADT: 274

260TH ST

Good

Over: BROPHYS CREEK

081E53001, Clinton, IA

Built 1985 Load: 33.1 t ADT: 35

125TH STREET

Good

Over: DEEP CREEK

083E51703, Clinton, IA

Built 1977 Load: 33.1 t ADT: 100

460TH AVE.

Good

Over: ELK RIVER

083E61204, Clinton, IA

Built 1986 Load: 33.1 t ADT: 82

US 20 EB

Good

Over: STREAM

0.9 MILE W OF JCT SR T55, Grundy, IA

Built 2000 Load: 33.1 t ADT: 6,750

LOCAL

Good

Over: STREAM

081330502, Guthrie, IA

Built 1997 Load: 33.1 t ADT: 20

IRELAND AVENUE

Good

Over: CLEAR CREEK

080073304, Johnson, IA

Built 1973 Load: 33.1 t ADT: 8,339

US 61 SB

Good

Over: JACK CREEK

1.7 MI. N OF JCT. US 218, Lee, IA

Built 1998 Load: 33.1 t ADT: 3,050

LOCAL

Good

Over: OCHEYEDAN RIVER

099400801, Osceola, IA

Built 1975 Load: 33.1 t ADT: 90

SB US 65

Good

Over: OVER UP RR

1.9 MILES N OF N JCT IA 5, Polk, IA

Built 1997 Load: 33.1 t ADT: 12,450

ORANGE AVENUE

Good

Over: SMALL STREAM

077071708, Washington, IA

Built 2019 Load: 33.1 t ADT: 131

LOCAL

Good

Over: THISTLE CREEK

088272201, Webster, IA

Built 1980 Load: 33.1 t ADT: 50

INDIGO

Good

Over: W BR BEAVER DAM CREEK

094212802, Cerro Gordo, IA

Built 1980 Load: 33.2 t ADT: 35

CLAY BANKS

Good

Over: LITTLE LIME CREEK

096192503, Cerro Gordo, IA

Built 1985 Load: 33.2 t ADT: 39

330TH

Good

Over: BLAIR CREEK

097200901, Cerro Gordo, IA

Built 1966 Load: 33.2 t ADT: 236

SB US 61

Good

Over: DEEP CREEK

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

Built 1996 Load: 33.2 t ADT: 4,400

WATERFORD RD WB

Good

Over: WALNUT CREEK

P40000350, Dallas, IA

Built 2007 Load: 33.2 t ADT: 266

LOCAL ROAD

Good

Over: STREAM

078330303, Guthrie, IA

Built 1996 Load: 33.2 t ADT: 20

MAPLE AVE

Good

Over: STREAM

081310602, Guthrie, IA

Built 2015 Load: 33.2 t ADT: 29

LOCAL

Good

Over: BRANCH OLD MAN'S CREEK

079093503, Iowa, IA

Built 1999 Load: 33.2 t ADT: 40

IA 10

Good

Over: LITTLE CEDAR CREEK

3.7 mi. W of SR N28, Pocahontas, IA

Built 1988 Load: 33.2 t ADT: 1,230

Showing 12,351-12,400 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.