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

180TH

Fair

Over: E BR BEAVER DAM CREEK

095202901, Cerro Gordo, IA

Built 1965 Load: 36.3 t ADT: 26

580TH ST

Fair

Over: WILLOW CREEK

091413001, Cherokee, IA

Built 2015 Load: 36.3 t ADT: 26

US 18

Fair

Over: BEAVER CREEK

3.7 MI. W OF SR V14, Chickasaw, IA

Built 1978 Load: 36.3 t ADT: 2,120

FM

Fair

Over: FOX RIVER

068120502, Davis, IA

Built 1974 Load: 36.3 t ADT: 310

D22 210TH ST

Fair

Over: BR PRAIRIE CREEK

089063507, Delaware, IA

Built 1953 Load: 36.3 t ADT: 3,015

LOC BUC-DEL AVE

Fair

Over: SPRING BRANCH CREEK

089060702, Delaware, IA

Built 1983 Load: 36.3 t ADT: 33

120TH ST

Fair

Over: STREAM

090041301, Delaware, IA

Built 1985 Load: 36.3 t ADT: 26

LOC 255TH AVE

Fair

Over: BR ALMORAL CR

089040304, Delaware, IA

Built 1989 Load: 36.3 t ADT: 29

MONROE ST NE

Fair

Over: CREEK

000000000, Dubuque, IA

Built 1929 Load: 36.3 t ADT: 424

Y AVE

Fair

Over: LITTLE WAPSI RIVER

092101802, Fayette, IA

Built 1970 Load: 36.3 t ADT: 570

95TH ST

Fair

Over: MAYNES CREEK

091202905, Franklin, IA

Built 1988 Load: 36.3 t ADT: 51

FM 160TH ST

Fair

Over: OTTER CREEK

092192901, Franklin, IA

Built 1975 Load: 36.3 t ADT: 88

FM

Fair

Over: BEAVER CREEK

089172202, Grundy, IA

Built 1972 Load: 36.3 t ADT: 79

LOCAL

Fair

Over: CREEK

086210501, Hardin, IA

Built 1991 Load: 36.3 t ADT: 51

LOCAL

Fair

Over: CREEK

088212502, Hardin, IA

Built 1991 Load: 36.3 t ADT: 98

US 30

Fair

Over: POWLEY DRAIN DITCH

2.2 mi. E of SR F32, Harrison, IA

Built 1983 Load: 36.3 t ADT: 3,090

LOCAL

Fair

Over: BIG CREEK

071062810, Henry, IA

Built 1991 Load: 36.3 t ADT: 1,070

COUNTY RD E-45

Fair

Over: SMALL CREEK

083011605, Jones, IA

Built 1985 Load: 36.3 t ADT: 216

FM

Fair

Over: S FORK ENGLISH RIVER

077112102, Keokuk, IA

Built 1974 Load: 36.3 t ADT: 80

ELY RD

Fair

Over: ABANDONED RR

082071101, Linn, IA

Built 1976 Load: 36.3 t ADT: 5,095

SAWYER RD

Fair

Over: BUFFALO CREEK

085050505, Linn, IA

Built 1973 Load: 36.3 t ADT: 1,100

NB I-380

Fair

Over: WEST OTTER CREEK

2.7 mi. N of jct. SR E34, Linn, IA

Built 1983 Load: 36.3 t ADT: 12,850

FM

Fair

Over: CHARITON RIVER

071221502, Lucas, IA

Built 1975 Load: 36.3 t ADT: 60

NB I-29

Fair

Over: BNSF RR & EATON DITCH

0.8 MI N OF S JCT. US 34, Mills, IA

Built 1970 Load: 36.3 t ADT: 6,800

450TH

Fair

Over: LITTLE CEDAR RIVER

099160803, Mitchell, IA

Built 1992 Load: 36.3 t ADT: 78

QUAIL AVE

Fair

Over: CREEK

100162302, Mitchell, IA

Built 1977 Load: 36.3 t ADT: 29

FM

Fair

Over: OCHEYEDAN RIVER

098390801, Osceola, IA

Built 1973 Load: 36.3 t ADT: 738

HACKBERRY AVE

Fair

Over: LONG BRANCH

067382104, Page, IA

Built 1975 Load: 36.3 t ADT: 199

HACKBERRY AVE

Fair

Over: STREAM

067382806, Page, IA

Built 1975 Load: 36.3 t ADT: 141

LOCAL

Fair

Over: DD 80

096322602, Palo Alto, IA

Built 1992 Load: 36.3 t ADT: 21

LOCAL

Fair

Over: BOYER RIVER

087370401, Sac, IA

Built 1974 Load: 36.3 t ADT: 15

LOCAL

Fair

Over: BOYER RIVER

087372701, Sac, IA

Built 1979 Load: 36.3 t ADT: 15

FM

Fair

Over: BOYER RIVER

088370801, Sac, IA

Built 1975 Load: 36.3 t ADT: 100

FM

Fair

Over: BOYER RIVER

089372602, Sac, IA

Built 1976 Load: 36.3 t ADT: 26

I-280 (EB)

Fair

Over: DUCK CREEK

3.4 MI. S OF JCT. I-80, Scott, IA

Built 1972 Load: 36.3 t ADT: 11,750

FM

Fair

Over: EAST BR W NISHNABOTNA

078380703, Shelby, IA

Built 1965 Load: 36.3 t ADT: 278

640TH AVE

Fair

Over: EAST BR INDIAN CREEK

1.3 miles S of E18, Story, IA

Built 2015 Load: 36.3 t ADT: 15

FM

Fair

Over: D.D.NO.90

092241403, Wright, IA

Built 1993 Load: 36.3 t ADT: 450

FM

Fair

Over: SOUTH SOAP CREEK

070162502, Appanoose, IA

Built 1990 Load: 36.4 t ADT: 850

FM

Fair

Over: WILD CAT CREEK

083100501, Benton, IA

Built 1990 Load: 36.4 t ADT: 40

LOCAL

Fair

Over: PRAIRIE CREEK

086102503, Benton, IA

Built 1990 Load: 36.4 t ADT: 49

FM

Fair

Over: MAPLE CREEK

092382902, Buena Vista, IA

Built 1988 Load: 36.4 t ADT: 729

FM

Fair

Over: SUGAR CREEK

080022503, Cedar, IA

Built 1997 Load: 36.4 t ADT: 60

FM

Fair

Over: MUDDY CREEK

098350901, Dickinson, IA

Built 1989 Load: 36.4 t ADT: 1,422

I 35 SB

Fair

Over: FINK CATTLE PASS

0.5 mi. S of Jct. IA 3, Franklin, IA

Built 1973 Load: 36.4 t ADT: 8,250

NB US 61

Fair

Over: LOST CREEK

2.4 mi. S of Jct. IA 16, Lee, IA

Built 1966 Load: 36.4 t ADT: 4,550

FM

Fair

Over: WALNUT CREEK

075383401, Pottawattamie, IA

Built 1981 Load: 36.4 t ADT: 40

US 34 & IA 25

Fair

Over: BRANCH PLATTE RIVER

1.0 MI. E OF W JCT IA 25, Union, IA

Built 1973 Load: 36.4 t ADT: 3,730

IA 188

Fair

Over: TWO MILE CREEK

0.9 mi. W of Sec. Rd. V14, Bremer, IA

Built 1979 Load: 36.5 t ADT: 930

R AVE / P30

Fair

Over: RACCOON RIVER

083303602, Greene, IA

Built 1975 Load: 36.5 t ADT: 190

Showing 7,751-7,800 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.