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

K30 ELMWOOD AVE

Good

Over: ROCK RIVER

097461606, Sioux, IA

Built 2017 Load: 36.0 t ADT: 2,963

140TH AVE

Good

Over: SMALL STREAM

071143508, Wapello, IA

Built 2018 Load: 36.0 t ADT: 110

RAMP B (EB)

Good

Over: CEDAR RIVER OVERFLOW

At Jct. U.S. 218 & IA 57, Black Hawk, IA

Built 1995 Load: 36.1 t ADT: 3,400

US 218 NB

Good

Over: OVRFLW AVE SAINTS LAKE

0.7 Mi. S of Jct. IA #3, Bremer, IA

Built 1996 Load: 36.1 t ADT: 4,850

LOCAL

Good

Over: DRAINAGE DITCH

091383002, Buena Vista, IA

Built 2000 Load: 36.1 t ADT: 15

LOCAL

Good

Over: SMALL STREAM

090150702, Butler, IA

Built 1996 Load: 36.1 t ADT: 49

SPRING AVE.

Good

Over: SMALL STREAM

090153104, Butler, IA

Built 1999 Load: 36.1 t ADT: 62

FOREST AVE

Good

Over: SMALL STREAM

091182402, Butler, IA

Built 2000 Load: 36.1 t ADT: 30

150TH ST

Good

Over: STREAM

093153501, Butler, IA

Built 2005 Load: 36.1 t ADT: 51

302 STREET

Good

Over: SMALL

090151303, Butler, IA

Built 2003 Load: 36.1 t ADT: 34

310TH STREET

Good

Over: SMALL

090162201, Butler, IA

Built 2005 Load: 36.1 t ADT: 49

LOCAL-640TH ST

Good

Over: SMALL CREEK

090422801, Cherokee, IA

Built 2005 Load: 36.1 t ADT: 30

LOCAL 560TH ST.

Good

Over: PERRY CREEK

091401801, Cherokee, IA

Built 2001 Load: 36.1 t ADT: 15

FM F AVE

Good

Over: N FORK LITTLE SIOUX

093422402, Cherokee, IA

Built 2001 Load: 36.1 t ADT: 40

LOCAL

Good

Over: SPRING BRANCH

095121901, Chickasaw, IA

Built 1998 Load: 36.1 t ADT: 91

ODESSA

Good

Over: PLUM CREEK

096123402, Chickasaw, IA

Built 2000 Load: 36.1 t ADT: 21

US 67

Good

Over: ROCK CREEK

IN CAMANCHE, Clinton, IA

Built 1982 Load: 36.1 t ADT: 3,710

102ND AVE

Good

Over: SMALL STREAM

081E13106, Clinton, IA

Built 2000 Load: 36.1 t ADT: 26

LOCAL

Good

Over: FLOOD CREEK

097182901, Floyd, IA

Built 1996 Load: 36.1 t ADT: 49

LOCAL SEC RD

Good

Over: WATERMAN CREEK

097393001, O'Brien, IA

Built 1988 Load: 36.1 t ADT: 50

FM

Good

Over: STREAM

098422302, Osceola, IA

Built 1977 Load: 36.1 t ADT: 120

LOCAL

Good

Over: CREEK

067342203, Taylor, IA

Built 1992 Load: 36.1 t ADT: 26

FM

Good

Over: CREEK

067101101, Van Buren, IA

Built 2002 Load: 36.1 t ADT: 25

US 34 EB

Good

Over: SUGAR CREEK

0.8 mi. E of E Jct. US 63, Wapello, IA

Built 2005 Load: 36.1 t ADT: 4,650

US 34 WB

Good

Over: SUGAR CREEK

0.8 mi. E of E Jct. US 63, Wapello, IA

Built 2005 Load: 36.1 t ADT: 4,650

US 63 NB

Good

Over: DME RR

1.6 mi. S of Jct. IA 149, Wapello, IA

Built 2007 Load: 36.1 t ADT: 3,000

IA 28

Good

Over: SOUTH MIDDLE CREEK

0.6 MI. S OF Jct. IA 5, Warren, IA

Built 1984 Load: 36.1 t ADT: 18,500

LOCAL

Good

Over: DD

088283002, Webster, IA

Built 1997 Load: 36.1 t ADT: 46

LOCAL

Good

Over: DEER CREEK

090290910, Webster, IA

Built 1998 Load: 36.1 t ADT: 26

NB US 218

Good

Over: SINK CREEK

.7 mi S of jct US 20/I380, Black Hawk, IA

Built 1983 Load: 36.2 t ADT: 6,050

FM

Good

Over: BEAVER CREEK

090152804, Butler, IA

Built 1984 Load: 36.2 t ADT: 1,100

230TH ST

Good

Over: CREEK

081E20901, Clinton, IA

Built 1990 Load: 36.2 t ADT: 35

LOCAL

Good

Over: CREEK

082E32204, Clinton, IA

Built 1995 Load: 36.2 t ADT: 11

400TH AVENUE

Good

Over: CREEK

083E60702, Clinton, IA

Built 1953 Load: 36.2 t ADT: 880

415TH AVE.

Good

Over: BRANCH OF ELK RIVER

083E61706, Clinton, IA

Built 1996 Load: 36.2 t ADT: 5

FM

Good

Over: FLINT RIVER

070030907, Des Moines, IA

Built 1978 Load: 36.2 t ADT: 210

N 75TH AVE E

Good

Over: SMALL STREAM

081193603, Jasper, IA

Built 2015 Load: 36.2 t ADT: 16

SW KANSAS AVE

Good

Over: OLD MANS CREEK

079073502, Johnson, IA

Built 2000 Load: 36.2 t ADT: 30

FM

Good

Over: SMALL STREAM

100431702, Lyon, IA

Built 1977 Load: 36.2 t ADT: 45

E64 REDWOOD AVE

Good

Over: BRANCH OF ELK CREEK

082432400, Monona, IA

Built 2022 Load: 36.2 t ADT: 34

LOCAL

Good

Over: DRAINAGE

072161003, Monroe, IA

Built 2003 Load: 36.2 t ADT: 15

NE 54TH AVE

Good

Over: MUD CREEK

079221701, Polk, IA

Built 2011 Load: 36.2 t ADT: 548

FM

Good

Over: LYONS CREEK

080392403, Shelby, IA

Built 1992 Load: 36.2 t ADT: 450

FM

Good

Over: MIDDLE NODAWAY RIVER

074333402, Adair, IA

Built 2005 Load: 36.3 t ADT: 34

LEWIS AVE

Good

Over: NODAWAY CREEK

3.4 mi S of G35 on Lewis, Adair, IA

Built 2020 Load: 36.3 t ADT: 62

BROWN AVE

Good

Over: STREAM

0.6 mi S of 92 on Brown, Adair, IA

Built 2016 Load: 36.3 t ADT: 62

FM

Good

Over: ROCK CK

085120502, Benton, IA

Built 1989 Load: 36.3 t ADT: 20

OSAGE RD

Good

Over: SPRING CREEK

89-11-36-01-10, Black Hawk, IA

Built 1985 Load: 36.3 t ADT: 648

FM

Good

Over: BLUFF CREEK

085272902, Boone, IA

Built 1987 Load: 36.3 t ADT: 977

US 218 SB

Good

Over: OVERFLOW AVE SAINTS LAKE

0.7 mi. S of Jct. Ia. #3, Bremer, IA

Built 1996 Load: 36.3 t ADT: 4,850

Showing 13,101-13,150 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.