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

FM

Fair

Over: CREEK

073101201, Jefferson, IA

Built 1996 Load: 32.7 t ADT: 190

FM

Fair

Over: OVER BNSF RR

072102704, Jefferson, IA

Built 1981 Load: 32.7 t ADT: 1,310

FM 340TH ST

Fair

Over: STREAM

079070601, Johnson, IA

Built 1900 Load: 32.7 t ADT: 260

JORDAN CK RD

Fair

Over: JORDAN CREEK

081062602, Johnson, IA

Built 1971 Load: 32.7 t ADT: 72

1ST AVE

Fair

Over: RALSTON CREEK N. BRANCH

079061200, Johnson, IA

Built 1984 Load: 32.7 t ADT: 7,143

GOLFVIEW DRIVE

Fair

Over: MUDDY CREEK

East of Crandic RR, Johnson, IA

Built 2012 Load: 32.7 t ADT: 1,480

RACHAEL STREET

Fair

Over: MUDDY CREEK

East of Crandic RR, Johnson, IA

Built 2003 Load: 32.7 t ADT: 240

3RD STREET

Fair

Over: FAWN CREEK

084041103, Jones, IA

Built 1965 Load: 32.7 t ADT: 7,954

62ND STREET

Fair

Over: SMALL CREEK

083020103, Jones, IA

Built 1980 Load: 32.7 t ADT: 11

COUNTY RD X-40

Fair

Over: TRIB TO WALNUT CREEK

083031804, Jones, IA

Built 1998 Load: 32.7 t ADT: 770

30TH ST.

Fair

Over: SMALL

083042903, Jones, IA

Built 1978 Load: 32.7 t ADT: 79

IA 21

Fair

Over: STREAM

0.6 MI. S OF JCT. IA 22, Keokuk, IA

Built 1940 Load: 32.7 t ADT: 1,950

LOCAL

Fair

Over: SMALL

076110905, Keokuk, IA

Built 1979 Load: 32.7 t ADT: 25

LOCAL

Fair

Over: GERMAN CREEK

076112702, Keokuk, IA

Built 1990 Load: 32.7 t ADT: 20

LOCAL

Fair

Over: STREAM

076132004, Keokuk, IA

Built 1977 Load: 32.7 t ADT: 20

FM

Fair

Over: TRIB S FORK ENGLISH RVR

077121504, Keokuk, IA

Built 1987 Load: 32.7 t ADT: 460

FM 190TH ST

Fair

Over: DRY RUN

095271901, Kossuth, IA

Built 1997 Load: 32.7 t ADT: 240

FM 210TH ST

Fair

Over: PURCELL CREEK

095280903, Kossuth, IA

Built 1987 Load: 32.7 t ADT: 878

FM PLUM CK RD

Fair

Over: OAK LAKE SPILLWAY

096282003, Kossuth, IA

Built 1972 Load: 32.7 t ADT: 688

350TH STREET

Fair

Over: LITTLE BUFFALO CREEK

098273501, Kossuth, IA

Built 1999 Load: 32.7 t ADT: 15

LOC 50TH AVE

Fair

Over: PRAIRIE CREEK

099303502, Kossuth, IA

Built 2007 Load: 32.7 t ADT: 21

AVE H

Fair

Over: FRENCH CREEK

067040401, Lee, IA

Built 1983 Load: 32.7 t ADT: 10,382

LOCAL

Fair

Over: HOG THIEF HOLLOW

065053303, Lee, IA

Built 1977 Load: 32.7 t ADT: 100

FM

Fair

Over: DRAINAGE DITCH

068032103, Lee, IA

Built 1964 Load: 32.7 t ADT: 100

FM

Fair

Over: DRAINAGE DITCH

068032602, Lee, IA

Built 1961 Load: 32.7 t ADT: 260

FM

Fair

Over: MUD CREEK

068042304, Lee, IA

Built 1972 Load: 32.7 t ADT: 410

LOCAL

Fair

Over: BONNELL CREEK

068061406, Lee, IA

Built 1978 Load: 32.7 t ADT: 34

FM

Fair

Over: CREEK

068070702, Lee, IA

Built 1963 Load: 32.7 t ADT: 470

LOCAL

Fair

Over: LOST CREEK

069043102, Lee, IA

Built 1978 Load: 32.7 t ADT: 100

LOCAL

Fair

Over: LITTLE SUGAR CREEK

068070902, Lee, IA

Built 1977 Load: 32.7 t ADT: 26

LOCAL

Fair

Over: SMALL STREAM

066070104, Lee, IA

Built 1977 Load: 32.7 t ADT: 40

FM

Fair

Over: CREEK

069042604, Lee, IA

Built 1975 Load: 32.7 t ADT: 60

IA 922-1ST AVE

Fair

Over: CEDAR RIVER

0.2 MI. N OF I-380, Linn, IA

Built 1920 Load: 32.7 t ADT: 13,000

GREEN RIDGE RD

Fair

Over: CLEAR CREEK

082053606, Linn, IA

Built 1992 Load: 32.7 t ADT: 59

C ST RD

Fair

Over: HOOSIER CREEK

082072302, Linn, IA

Built 1984 Load: 32.7 t ADT: 1,099

CEDAR RIDGE RD.

Fair

Over: BLUE CREEK

085080703, Linn, IA

Built 1989 Load: 32.7 t ADT: 147

STATE ST

Fair

Over: APPLE CREEK

State Street, Linn, IA

Built 1989 Load: 32.7 t ADT: 232

OAK CREEK DR NW

Fair

Over: DRAINAGE

000000000, Linn, IA

Built 1993 Load: 32.7 t ADT: 40

44TH STREET

Fair

Over: WANATEE CREEK

083060500, Linn, IA

Built 1980 Load: 32.7 t ADT: 8,192

8TH AVENUE

Fair

Over: WANATEE CREEK

083060400, Linn, IA

Built 2003 Load: 32.7 t ADT: 510

BOYSON RD

Fair

Over: TRIBUTARY OF DRY CREEK

084073500, Linn, IA

Built 1976 Load: 32.7 t ADT: 13,287

SB I-380

Fair

Over: CC RR & ASH PIT

2.9 MI. S OF JCT. 100, Linn, IA

Built 1979 Load: 32.7 t ADT: 41,000

SE RAMP I-380

Fair

Over: OVER CC RR & TRAIL

0.2 mi. S of Jct. IA 100, Linn, IA

Built 1982 Load: 32.7 t ADT: 7,700

US 151

Fair

Over: CREEK

2.5 MI. S OF JCT. IA 100, Linn, IA

Built 1960 Load: 32.7 t ADT: 22,400

LOCAL

Fair

Over: SMALL STREAM

073013301, Louisa, IA

Built 1998 Load: 32.7 t ADT: 15

LOCAL

Fair

Over: MICHAEL CREEK

074030112, Louisa, IA

Built 1983 Load: 32.7 t ADT: 650

LOCAL

Fair

Over: JOHNNY CREEK

074040701, Louisa, IA

Built 1989 Load: 32.7 t ADT: 82

LOCAL

Fair

Over: SMALL STREAM

074050302, Louisa, IA

Built 1983 Load: 32.7 t ADT: 82

LOCAL

Fair

Over: SMALL STREAM

074050402, Louisa, IA

Built 1991 Load: 32.7 t ADT: 30

LOCAL

Fair

Over: SMALL STREAM

075032004, Louisa, IA

Built 1994 Load: 32.7 t ADT: 21

Showing 6,701-6,750 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.