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

340TH STREET

Fair

Over: MIDDLE SILVER CREEK

076413504, Pottawattamie, IA

Built 1998 Load: 37.2 t ADT: 270

FM

Fair

Over: BRANCH SALT CREEK

085132002, Tama, IA

Built 1998 Load: 37.2 t ADT: 727

FM

Fair

Over: LEWIS CREEK

067081204, Van Buren, IA

Built 1985 Load: 37.2 t ADT: 200

FM

Fair

Over: WHITE BREAST

074222403, Warren, IA

Built 1988 Load: 37.2 t ADT: 500

LOCAL

Fair

Over: NORTH FORK YELLOW RIVER

096070304, Winneshiek, IA

Built 1984 Load: 37.2 t ADT: 29

LOCAL

Fair

Over: SMALL STREAM

097083606, Winneshiek, IA

Built 1900 Load: 37.2 t ADT: 39

LOCAL

Fair

Over: SMALL

098100306, Winneshiek, IA

Built 1978 Load: 37.2 t ADT: 88

E 4TH ST

Fair

Over: VIRDEN CREEK

CITY CULVERT NO. 38C, Black Hawk, IA

Built 1970 Load: 37.3 t ADT: 2,679

460TH ST

Fair

Over: STREAM

094371203, Clay, IA

Built 1994 Load: 37.3 t ADT: 41

CREEKWOOD DR

Fair

Over: CATFISH CREEK

W. OF MANSON RD., Dubuque, IA

Built 2006 Load: 37.3 t ADT: 549

LOCAL

Fair

Over: NATURAL CREEK

0993436, Emmet, IA

Built 1985 Load: 37.3 t ADT: 71

BUS BROWN DR

Fair

Over: UNNAMED CREEK

East of Lincolnway, Harrison, IA

Built 2015 Load: 37.3 t ADT: 1,225

FM

Fair

Over: CREEK

084E10104, Jackson, IA

Built 1956 Load: 37.3 t ADT: 50

20TH AVE.

Fair

Over: BEERS CREEK

084011302, Jones, IA

Built 1970 Load: 37.3 t ADT: 34

30TH AVE

Fair

Over: CREEK

079E12702, Scott, IA

Built 1993 Load: 37.3 t ADT: 15

220TH AVE

Fair

Over: CREEK

079E42901, Scott, IA

Built 1921 Load: 37.3 t ADT: 150

288TH ST

Fair

Over: MUD CREEK OVERFLOW

080E22205, Scott, IA

Built 1991 Load: 37.3 t ADT: 45

LOCAL

Fair

Over: SMALL STREAM

079E13402, Scott, IA

Built 1993 Load: 37.3 t ADT: 71

FM

Fair

Over: EAST BRANCH PLATTE RIVER

072303003, Union, IA

Built 1979 Load: 37.3 t ADT: 89

FM

Fair

Over: STREAM

069201406, Wayne, IA

Built 1951 Load: 37.3 t ADT: 70

SB US 63

Fair

Over: QUARTER SECTION RUN

0.5 mi. S of Jct. SR C50, Bremer, IA

Built 1994 Load: 37.4 t ADT: 2,900

BENJAMIN AVE

Fair

Over: CHESLEA CREEK

000000000, Cerro Gordo, IA

Built 1982 Load: 37.4 t ADT: 147

26TH ST. S.W.

Fair

Over: CHESLEA CREEK

000000000, Cerro Gordo, IA

Built 1989 Load: 37.4 t ADT: 644

LOCAL

Fair

Over: HONEY CREEK

086201606, Hardin, IA

Built 1988 Load: 37.4 t ADT: 15

SW BUCHANAN AVE

Fair

Over: DRAINAGE

078082004, Johnson, IA

Built 1974 Load: 37.4 t ADT: 15

WRIGHT BROS BLV

Fair

Over: HOOSIER CREEK

082072603, Linn, IA

Built 1985 Load: 37.4 t ADT: 1,728

LOCAL

Fair

Over: BIG SLOUGH CREEK

074050902, Louisa, IA

Built 1988 Load: 37.4 t ADT: 16

US 63

Fair

Over: MIDDLE CREEK

3.3 mi. S of jct. IA 146, Mahaska, IA

Built 1961 Load: 37.4 t ADT: 4,240

FM

Fair

Over: SNIPE CREEK

082193301, Marshall, IA

Built 1980 Load: 37.4 t ADT: 39

EB US 34

Fair

Over: BNSF RR

0.5 MI E OF E JCT I-29, Mills, IA

Built 1973 Load: 37.4 t ADT: 5,900

IA 28 NB

Fair

Over: RACCOON RIVER

2.1 MILES S OF JCT I-235, Polk, IA

Built 1994 Load: 37.4 t ADT: 12,650

US 169

Fair

Over: DRAINAGE DITCH #96

2.5 mi. S of jct. US 20, Webster, IA

Built 1973 Load: 37.4 t ADT: 3,470

STATE STREET

Fair

Over: QUARTER SECTION RUN CRK

A65000535, Bremer, IA

Built 1969 Load: 37.5 t ADT: 1,339

11TH ST

Fair

Over: LATERAL #77 DD #23

000000000, Carroll, IA

Built 1900 Load: 37.5 t ADT: 1,112

278TH ST

Fair

Over: DRAINAGE

080E20205, Clinton, IA

Built 1996 Load: 37.5 t ADT: 170

340TH AVENUE

Fair

Over: CREEK

082E53102, Clinton, IA

Built 1965 Load: 37.5 t ADT: 35

130TH ST

Fair

Over: CREEK

083E22301, Clinton, IA

Built 1970 Load: 37.5 t ADT: 16

140TH ST.

Fair

Over: CREEK

083E32501, Clinton, IA

Built 1967 Load: 37.5 t ADT: 21

LOCAL

Fair

Over: CREEK

088250906, Hamilton, IA

Built 1918 Load: 37.5 t ADT: 11

LOCAL

Fair

Over: STREAM

074110603, Keokuk, IA

Built 1950 Load: 37.5 t ADT: 20

US 59

Fair

Over: EAST NISHNABOTNA RIVER

1.0 MI. N. OF IA. 48, Page, IA

Built 1929 Load: 37.5 t ADT: 1,780

ARRASMITH TRL

Fair

Over: D D

084242308, Story, IA

Built 1996 Load: 37.5 t ADT: 319

JUNIPER AVENUE

Fair

Over: MIDDLE NODAWAY RIVER

073342304, Adams, IA

Built 2002 Load: 37.6 t ADT: 20

W.4TH ST

Fair

Over: DRAINAGE

CITY CULVERT NO. 35C, Black Hawk, IA

Built 1986 Load: 37.6 t ADT: 5,322

US 71

Fair

Over: DRAINAGE DITCH #34

3.0 mi. N of IA 3, Buena Vista, IA

Built 1985 Load: 37.6 t ADT: 3,830

I-35

Fair

Over: DRAINAGE DITCH

At the jct. SR B60, Cerro Gordo, IA

Built 1972 Load: 37.6 t ADT: 17,400

FM 390TH ST

Fair

Over: LITTLE SIOUX RIVER

095360201, Clay, IA

Built 1986 Load: 37.6 t ADT: 40

350TH ST

Fair

Over: LITTLE SIOUX RIVER

096371405, Clay, IA

Built 1976 Load: 37.6 t ADT: 2,584

FM

Fair

Over: SEELY CREEK

079331408, Guthrie, IA

Built 1958 Load: 37.6 t ADT: 450

S 124TH AVE E

Fair

Over: ELK CREEK

078183605, Jasper, IA

Built 1987 Load: 37.6 t ADT: 45

Showing 7,901-7,950 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.