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

110TH

Fair

Over: COLD WATER CREEK

094193501, Cerro Gordo, IA

Built 1948 Load: 18.1 t ADT: 15

IA 143

Fair

Over: STREAM

2.2 mi. N of IA 3, Cherokee, IA

Built 1957 Load: 18.1 t ADT: 1,490

LOCAL 580TH ST.

Fair

Over: WEST FORK LITTLE SIOUX

091422901, Cherokee, IA

Built 1961 Load: 18.1 t ADT: 15

IA 346

Fair

Over: STREAM

0.7 MI. E OF E JCT SR T76, Chickasaw, IA

Built 1957 Load: 18.1 t ADT: 2,150

FM

Fair

Over: SMALL CREEK

071273302, Clarke, IA

Built 1958 Load: 18.1 t ADT: 219

NICKEL RD

Fair

Over: LITTLE TURKEY

091021604, Clayton, IA

Built 1935 Load: 18.1 t ADT: 62

BIGHORN RD

Fair

Over: HEWETT CREEK

092062204, Clayton, IA

Built 1920 Load: 18.1 t ADT: 51

FM

Fair

Over: EAST BOYER RIVER

083380304, Crawford, IA

Built 1958 Load: 18.1 t ADT: 89

LOCAL

Fair

Over: SMALL STREAM

083410302, Crawford, IA

Built 1983 Load: 18.1 t ADT: 11

LOCAL

Fair

Over: BUFFALO CREEK

084391003, Crawford, IA

Built 1960 Load: 18.1 t ADT: 5

US 30

Fair

Over: DRAINAGE DITCH

1.7 mi E of E Jct US 59, Crawford, IA

Built 1958 Load: 18.1 t ADT: 4,670

LOCAL

Fair

Over: STREAM

068262701, Decatur, IA

Built 1967 Load: 18.1 t ADT: 11

US 20 US 52

Fair

Over: DRAINAGE DITCH

0.8 MI. E OF JCT. SR Y21, Dubuque, IA

Built 1957 Load: 18.1 t ADT: 18,500

FM

Fair

Over: LITTLE CEDAR RIVER

097153102, Floyd, IA

Built 1959 Load: 18.1 t ADT: 79

190 STREET

Fair

Over: MUSTARD LAT

069432201, Fremont, IA

Built 1989 Load: 18.1 t ADT: 5

390 AVENUE

Fair

Over: HUNTER BRANCH

070402202, Fremont, IA

Built 1959 Load: 18.1 t ADT: 46

140 TH

Fair

Over: STREAM

085292901, Greene, IA

Built 1934 Load: 18.1 t ADT: 11

LOCAL

Fair

Over: S. RACCOON RIVER

078300405, Guthrie, IA

Built 1959 Load: 18.1 t ADT: 20

HIDDEN VALLY DR

Fair

Over: ELK RUN

000000000, Hardin, IA

Built 1977 Load: 18.1 t ADT: 66

IA 127

Fair

Over: LITTLE BLOOMER CREEK

2.7 mi. E of E jct IA 183, Harrison, IA

Built 1940 Load: 18.1 t ADT: 460

IA 78

Fair

Over: DRAINAGE DITCH

5.6 MI. E OF E JCT US 218, Henry, IA

Built 1931 Load: 18.1 t ADT: 180

H14 120TH ST

Fair

Over: LOCAL CREEK

073051801, Henry, IA

Built 1920 Load: 18.1 t ADT: 120

US 34

Fair

Over: DRAINAGE

2.1 mi. W of Jct. SR W-55, Henry, IA

Built 1956 Load: 18.1 t ADT: 6,800

LOCAL

Fair

Over: DD

091292801, Humboldt, IA

Built 1900 Load: 18.1 t ADT: 20

W 21 (U AVE)

Fair

Over: STREAM

AT JCT. I-80, Iowa, IA

Built 1963 Load: 18.1 t ADT: 10

LOCAL

Fair

Over: SUGAR CREEK

080212703, Jasper, IA

Built 1991 Load: 18.1 t ADT: 91

US 6

Fair

Over: STREAM

3.1 MI. E OF JCT. SR W38, Johnson, IA

Built 1953 Load: 18.1 t ADT: 5,200

US 6

Fair

Over: PIG RUN CREEK

4.1 mi. E of Jct. SR W-38, Johnson, IA

Built 1923 Load: 18.1 t ADT: 5,200

IA 38

Fair

Over: STREAM

3.7 MI. N OF N JCT. IA 64, Jones, IA

Built 1957 Load: 18.1 t ADT: 630

IA 38

Fair

Over: DRAINAGE DITCH

5.8 MI. N OF E JCT IA 64, Jones, IA

Built 1957 Load: 18.1 t ADT: 630

200TH AVE.

Fair

Over: N FK WALNUT CREEK

083041204, Jones, IA

Built 1985 Load: 18.1 t ADT: 47

LOCAL

Fair

Over: STREAM

076103301, Keokuk, IA

Built 1990 Load: 18.1 t ADT: 15

LOC 440TH ST

Fair

Over: MUD CREEK

099301501, Kossuth, IA

Built 1977 Load: 18.1 t ADT: 30

LOCAL

Fair

Over: SUGAR CREEK WEST BRANCH

068061001, Lee, IA

Built 1959 Load: 18.1 t ADT: 120

US 30

Fair

Over: STREAM

2.5 mi. W of Jct. IA #1, Linn, IA

Built 1951 Load: 18.1 t ADT: 12,000

FM

Fair

Over: SMALL STREAM

074051407, Louisa, IA

Built 1960 Load: 18.1 t ADT: 50

IA 9

Fair

Over: STREAM

200 ft. S of Jct. SR K12, Lyon, IA

Built 1940 Load: 18.1 t ADT: 4,520

LOCAL RD

Fair

Over: MIDDLE RIVER

076273605, Madison, IA

Built 1960 Load: 18.1 t ADT: 71

FM

Fair

Over: STREAM

077261301, Madison, IA

Built 1936 Load: 18.1 t ADT: 1,714

FM

Fair

Over: NORTH RIVER

077273602, Madison, IA

Built 1961 Load: 18.1 t ADT: 50

IA 92

Fair

Over: STREAM

3.3 MI. W OF W JCT SR V13, Mahaska, IA

Built 1958 Load: 18.1 t ADT: 2,850

FM

Fair

Over: LONG BRANCH CREEK

074201704, Marion, IA

Built 1960 Load: 18.1 t ADT: 60

US 59

Fair

Over: STREAM

2.3 MI. S OF Jct. SR H-12, Mills, IA

Built 1939 Load: 18.1 t ADT: 940

KIRKWOOD AVE

Fair

Over: CREEK

097171404, Mitchell, IA

Built 1930 Load: 18.1 t ADT: 39

385TH

Fair

Over: SMALL STREAM

098171203, Mitchell, IA

Built 1973 Load: 18.1 t ADT: 49

FM

Fair

Over: WEST FORK DD

084450203, Monona, IA

Built 1961 Load: 18.1 t ADT: 34

LOCAL

Fair

Over: DIVERSION DITCH

084451301, Monona, IA

Built 1961 Load: 18.1 t ADT: 45

US 34

Fair

Over: STREAM

5.9 MI. E OF IOWA 5, Monroe, IA

Built 1962 Load: 18.1 t ADT: 3,900

FM

Fair

Over: CEDAR CREEK

071190504, Monroe, IA

Built 1958 Load: 18.1 t ADT: 60

IA 48

Fair

Over: STREAM

0.2 MI. S OF JCT. IA 34, Montgomery, IA

Built 1931 Load: 18.1 t ADT: 7,600

Showing 2,101-2,150 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.