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

LOCAL

Fair

Over: SMALL STREAM

081140802, Poweshiek, IA

Built 1986 Load: 37.9 t ADT: 26

NB US 61

Fair

Over: CROW CREEK

1.6 MI. N OF JCT. I-80, Scott, IA

Built 1981 Load: 37.9 t ADT: 17,750

FM

Fair

Over: ELK CREEK

081373002, Shelby, IA

Built 2005 Load: 37.9 t ADT: 439

IA 10

Fair

Over: STREAM

0.4 mi. W of jct. US 75, Sioux, IA

Built 1989 Load: 37.9 t ADT: 1,900

FM

Fair

Over: DES MOINES RIVER

070111705, Van Buren, IA

Built 1977 Load: 37.9 t ADT: 240

FM

Fair

Over: SOAP CREEK

071123504, Wapello, IA

Built 1994 Load: 37.9 t ADT: 140

FM

Fair

Over: OVER UP RR

077222906, Warren, IA

Built 1994 Load: 37.9 t ADT: 270

LOCAL

Fair

Over: YELLOW RIVER BRANCH

096070303, Winneshiek, IA

Built 1990 Load: 37.9 t ADT: 11

E.ORANGE RD

Fair

Over: SINK CREEK

CITY CULVERT NO. 45C, Black Hawk, IA

Built 1988 Load: 38.0 t ADT: 2,777

FM

Fair

Over: WORRELL CREEK

083251302, Boone, IA

Built 1985 Load: 38.0 t ADT: 518

EB I-80

Fair

Over: ABANDON RR

0.5 mi. E of Jct. SR X30, Cedar, IA

Built 1962 Load: 38.0 t ADT: 19,500

I 380 SB

Fair

Over: EAST OTTER CREEK

1.3 MI. N S.R. E34, Linn, IA

Built 1983 Load: 38.0 t ADT: 12,850

US 71

Fair

Over: STREAM

0.8 MI N OF N JCT SR J-20, Page, IA

Built 1972 Load: 38.0 t ADT: 2,090

LOCAL

Fair

Over: DRAINAGE

079E30208, Scott, IA

Built 1996 Load: 38.0 t ADT: 11

LOCAL

Fair

Over: CREEK

081351201, Audubon, IA

Built 1929 Load: 38.1 t ADT: 46

IA 57

Fair

Over: BEAVER CREEK

1.3 MI. E. OF Jct. SR T53, Butler, IA

Built 1928 Load: 38.1 t ADT: 2,220

SB I-29

Fair

Over: ALLEN CREEK

1.9 MI. N OF JCT. US 30, Harrison, IA

Built 1967 Load: 38.1 t ADT: 7,750

S 28TH AVE E

Fair

Over: ELK CREEK

079180707, Jasper, IA

Built 2000 Load: 38.1 t ADT: 710

WALTON LAKE DRIVE

Fair

Over: WALTON LAKE SPILLWAY

072093000, Jefferson, IA

Built 2003 Load: 38.1 t ADT: 65

SO. 6TH ST.

Fair

Over: LINN CREEK

083183400, Marshall, IA

Built 1984 Load: 38.1 t ADT: 11,300

STATE LINE ST

Fair

Over: LITTLE CEDAR RIVER

100160901, Mitchell, IA

Built 1985 Load: 38.1 t ADT: 26

LOCAL

Fair

Over: BEAR CREEK

080150402, Poweshiek, IA

Built 1988 Load: 38.1 t ADT: 5

300TH ST

Fair

Over: CONTENTION CREEK

080E31801, Scott, IA

Built 2004 Load: 38.1 t ADT: 20

IA 10

Fair

Over: DRY CREEK

0.4 mi W of IA 12, Sioux, IA

Built 1955 Load: 38.1 t ADT: 2,800

LARK AVENUE

Fair

Over: SMALL STREAM

071301202, Union, IA

Built 2002 Load: 38.1 t ADT: 30

FM

Fair

Over: BR UPPER IOWA RIVER

099061504, Allamakee, IA

Built 1997 Load: 38.2 t ADT: 69

LOCAL

Fair

Over: E BR W NISHNABOTNA

080360302, Audubon, IA

Built 1990 Load: 38.2 t ADT: 21

S CANFIELD RD

Fair

Over: TRIB TO CEDAR RIVER

88-11-32-02-10, Black Hawk, IA

Built 2004 Load: 38.2 t ADT: 599

LOCAL - 720TH

Fair

Over: W NODAWAY RIVER

074340702, Cass, IA

Built 1988 Load: 38.2 t ADT: 11

NO SHORE DR

Fair

Over: STREAM

096221500, Cerro Gordo, IA

Built 1972 Load: 38.2 t ADT: 953

WAUBONSIE AVENU

Fair

Over: WAUBONSIE CREEK

070431206, Fremont, IA

Built 1991 Load: 38.2 t ADT: 908

FM

Fair

Over: DRAINAGE DITCH

087222002, Hardin, IA

Built 1970 Load: 38.2 t ADT: 177

LOCAL

Fair

Over: SMALL CREEK

084E42204, Jackson, IA

Built 1990 Load: 38.2 t ADT: 26

FM

Fair

Over: MILL CREEK

094413402, O'Brien, IA

Built 1979 Load: 38.2 t ADT: 538

FM

Fair

Over: WALNUT CREEK

069293102, Ringgold, IA

Built 1992 Load: 38.2 t ADT: 270

US 218

Fair

Over: WHISKEY RUN CREEK

0.5 MI. N OF JCT. SR G-36, Washington, IA

Built 1984 Load: 38.2 t ADT: 14,900

IA 83

Fair

Over: CAMP CREEK

0.2 MI W OF Jct. SR M-56, Cass, IA

Built 1991 Load: 38.3 t ADT: 760

LOCAL

Fair

Over: SPRING BRANCH

095132402, Chickasaw, IA

Built 1995 Load: 38.3 t ADT: 91

FM/AUSTIN AVE

Fair

Over: SOLDIER RIVER

080451206, Harrison, IA

Built 1957 Load: 38.3 t ADT: 488

FM

Fair

Over: HESS CREEK

099433302, Lyon, IA

Built 1967 Load: 38.3 t ADT: 100

EB I-80

Fair

Over: OVER UP RR

2.3 MI. W OF W JCT. I-35, Dallas, IA

Built 1966 Load: 38.4 t ADT: 26,850

LOCAL

Fair

Over: TRIB TO MASON CREEK

079323201, Guthrie, IA

Built 1940 Load: 38.4 t ADT: 15

US 151 NB

Fair

Over: KITTY CREEK

0.4 MI. N OF JCT. SR X44, Jones, IA

Built 2002 Load: 38.4 t ADT: 4,200

LOC 150TH ST

Fair

Over: HINE CREEK

094301201, Kossuth, IA

Built 1991 Load: 38.4 t ADT: 11

FM

Fair

Over: SMALL STREAM

098460902, Lyon, IA

Built 1946 Load: 38.4 t ADT: 509

US 34

Fair

Over: DRAINAGE DITCH

1.3 mi. E of jct. SR L63, Mills, IA

Built 1964 Load: 38.4 t ADT: 4,260

LOCAL

Fair

Over: WRIGHT CREEK

0884230, Woodbury, IA

Built 1983 Load: 38.4 t ADT: 26

FM

Fair

Over: CREEK

081351302, Audubon, IA

Built 1946 Load: 38.5 t ADT: 40

US 169

Fair

Over: BRANCH BEAVER CREEK

1.0 MILE N OF W JCT US 30, Boone, IA

Built 1967 Load: 38.5 t ADT: 1,890

GARDEN AVE

Fair

Over: SMALL STREAM

093130602, Bremer, IA

Built 1951 Load: 38.5 t ADT: 15

Showing 8,001-8,050 of 20,753 bridges

Related

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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.