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: STREAM

070262207, Decatur, IA

Built 1994 Load: 32.7 t ADT: 15

H50 130TH AVE

Fair

Over: SHORT CREEK

070270302, Decatur, IA

Built 1988 Load: 32.7 t ADT: 11

LOCAL 320 AVE

Fair

Over: COOKSLEY CREEK

088031402, Delaware, IA

Built 1989 Load: 32.7 t ADT: 30

FM 195 ST

Fair

Over: HONEY CREEK

089052005, Delaware, IA

Built 1980 Load: 32.7 t ADT: 835

BACKBONE ST PK

Fair

Over: STREAM

IN BACKBONE STATE PARK, Delaware, IA

Built 1935 Load: 32.7 t

SUMMER ST

Fair

Over: SPRING CREEK

069032509, Des Moines, IA

Built 1988 Load: 32.7 t ADT: 1,530

LOCAL

Fair

Over: SMALL STREAM

070030806, Des Moines, IA

Built 2003 Load: 32.7 t ADT: 21

CENTRAL AVE

Fair

Over: BNSF RR

700234000, Des Moines, IA

Built 2006 Load: 32.7 t ADT: 5,350

WASHINGTON ST

Fair

Over: BNSF RR

700234000, Des Moines, IA

Built 2006 Load: 32.7 t ADT: 1,640

UNNAMED ROAD

Fair

Over: BRUSH CREEK

N OF STRUCTURE 05487, Des Moines, IA

Built 1946 Load: 32.7 t ADT: 5

PLANT ROAD P

Fair

Over: SPRING CREEK

APPROX. 8700' E. OF RD. H, Des Moines, IA

Built 1946 Load: 32.7 t ADT: 5

PLANT ROAD C

Fair

Over: LONG CREEK

APPROX. 1900' N. OF RD. I, Des Moines, IA

Built 1946 Load: 32.7 t ADT: 20

330TH AVE

Fair

Over: STREAM

098353602, Dickinson, IA

Built 1974 Load: 32.7 t ADT: 20

200TH ST

Fair

Over: STREAM

099383201, Dickinson, IA

Built 1978 Load: 32.7 t ADT: 11

180TH AVE

Fair

Over: STREAM

098372802, Dickinson, IA

Built 1955 Load: 32.7 t ADT: 26

210TH ST

Fair

Over: CREEK

098350101, Dickinson, IA

Built 1974 Load: 32.7 t ADT: 5

220TH ST

Fair

Over: STREAM

098360701, Dickinson, IA

Built 1952 Load: 32.7 t ADT: 2,834

120TH AVE

Fair

Over: STREAM

099380902, Dickinson, IA

Built 1978 Load: 32.7 t ADT: 11

IA 3

Fair

Over: N FORK MAQUOKETA RIVER

1.5 MI. S Jct. IA 136, Dubuque, IA

Built 1968 Load: 32.7 t ADT: 1,720

LOCAL

Fair

Over: CREEK

087E10303, Dubuque, IA

Built 2002 Load: 32.7 t ADT: 60

FM

Fair

Over: WHITE WATER CREEK

087011007, Dubuque, IA

Built 1988 Load: 32.7 t ADT: 590

STEGER RD

Fair

Over: N BR MAQUOKETA RIVER

087021803, Dubuque, IA

Built 2017 Load: 32.7 t ADT: 26

KEMP RD

Fair

Over: CREEK

088E30706, Dubuque, IA

Built 2000 Load: 32.7 t ADT: 520

LOCAL

Fair

Over: CREEK

088013304, Dubuque, IA

Built 2001 Load: 32.7 t ADT: 44

FM

Fair

Over: CREEK

088021505, Dubuque, IA

Built 2001 Load: 32.7 t ADT: 80

SEIPPEL RD

Fair

Over: MIDDLE FORK CATFISH CRK

N. OF CHAVENELLE RD, Dubuque, IA

Built 1949 Load: 32.7 t ADT: 3,632

LOCAL RD

Fair

Over: CREEK

089010704, Dubuque, IA

Built 1998 Load: 32.7 t ADT: 11

FM

Fair

Over: CREEK

090011204, Dubuque, IA

Built 1946 Load: 32.7 t ADT: 160

FM

Fair

Over: CLOIE CREEK

089E20504, Dubuque, IA

Built 1992 Load: 32.7 t ADT: 1,159

GRAF RD

Fair

Over: CREEK

089E13204, Dubuque, IA

Built 1985 Load: 32.7 t ADT: 678

CHAVENELLE RD

Fair

Over: MID FK CATFISH CREEK

W. OF SYNERGY COURT, Dubuque, IA

Built 1998 Load: 32.7 t ADT: 3,011

KEY WAY

Fair

Over: NORTH FORK CATFISH CREEK

0.04 MI N OF KEYSTONE DR, Dubuque, IA

Built 2010 Load: 32.7 t ADT: 1,932

US 61

Fair

Over: OTTER CREEK

0.3 MI. N of Jct. SR D55, Dubuque, IA

Built 1967 Load: 32.7 t ADT: 9,000

LOCAL

Fair

Over: SOLDIER CR

100322001, Emmet, IA

Built 1975 Load: 32.7 t ADT: 34

D AVE.

Fair

Over: DRY RUN TO BRUCE CREEK

091072702, Fayette, IA

Built 1929 Load: 32.7 t ADT: 59

G AVE.

Fair

Over: GUNDLACH CREEK

091073002, Fayette, IA

Built 1963 Load: 32.7 t ADT: 520

K AVE.

Fair

Over: STREAM

091082102, Fayette, IA

Built 1928 Load: 32.7 t ADT: 25

50TH ST.

Fair

Over: UNAMED CREEK

091091603, Fayette, IA

Built 2002 Load: 32.7 t ADT: 78

40TH ST.

Fair

Over: UNNAMED CREEK

091092401, Fayette, IA

Built 1987 Load: 32.7 t ADT: 78

30TH ST.

Fair

Over: HUNTER CREEK

091093001, Fayette, IA

Built 1996 Load: 32.7 t ADT: 78

25TH ST.

Fair

Over: HUNTER CR

091093003, Fayette, IA

Built 1999 Load: 32.7 t ADT: 5

R AVE.

Fair

Over: UNNAMED CREEK

091093202, Fayette, IA

Built 1994 Load: 32.7 t ADT: 59

70TH ST

Fair

Over: UNNAMED CREEK

091100101, Fayette, IA

Built 1995 Load: 32.7 t ADT: 33

Y AVE

Fair

Over: CREEK

091101904, Fayette, IA

Built 1965 Load: 32.7 t ADT: 962

40TH ST

Fair

Over: UNNAMED CREEK

091102201, Fayette, IA

Built 1925 Load: 32.7 t ADT: 314

W AVE

Fair

Over: SMALL STREAM

091103214, Fayette, IA

Built 1987 Load: 32.7 t ADT: 795

110TH ST.

Fair

Over: SMALL STREAM

092081301, Fayette, IA

Built 1988 Load: 32.7 t ADT: 15

J AVE

Fair

Over: SMALL

092083402, Fayette, IA

Built 1988 Load: 32.7 t ADT: 49

120TH ST

Fair

Over: UNNAMED CREEK

092100901, Fayette, IA

Built 1991 Load: 32.7 t ADT: 49

T AVE

Fair

Over: UNNAMED CR

092101202, Fayette, IA

Built 1988 Load: 32.7 t ADT: 79

Showing 6,451-6,500 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.