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

US 69

Fair

Over: WINNEBAGO RIVER

0.1 mi. S of S jct. IA 9, Winnebago, IA

Built 1988 Load: 46.3 t ADT: 5,400

IA 93

Fair

Over: WAPSIPINICON RIVER

1.3 mi. E of Tripoli, Bremer, IA

Built 1977 Load: 46.5 t ADT: 1,140

IA 83

Fair

Over: INDIAN CREEK

1.3 MI. W OF S.R. M56, Cass, IA

Built 1991 Load: 46.5 t ADT: 760

550TH ST

Fair

Over: SMALL STREAM

091371201, Buena Vista, IA

Built 1937 Load: 46.6 t ADT: 878

US 34 WB

Fair

Over: CHURCH CREEK

2.3 mi. E of Jct. SR V63, Jefferson, IA

Built 2007 Load: 46.6 t ADT: 3,900

FM- T AVE

Fair

Over: BRANCH MAPLE RIVER

090391702, Cherokee, IA

Built 1985 Load: 46.7 t ADT: 34

LUMBER RD

Fair

Over: SMALL

091033604, Clayton, IA

Built 1976 Load: 46.7 t ADT: 70

US 34

Fair

Over: ABANDON RR BIKE PATH

1.1 mi. W of Jct. IA 14, Lucas, IA

Built 1960 Load: 46.7 t ADT: 3,400

FM

Fair

Over: LITTLE BEAR CREEK

080152704, Poweshiek, IA

Built 1977 Load: 46.7 t ADT: 30

J23 170TH ST

Fair

Over: DRAINAGE DITCH

069331101, Taylor, IA

Built 1935 Load: 46.7 t ADT: 309

IA 148

Fair

Over: MIDDLE CREEK

0.1 MI. N OF JCT. SR J35, Taylor, IA

Built 1961 Load: 46.7 t ADT: 940

SB I-380

Fair

Over: LIME CREEK

0.7 MI. N OF JCT. SR D48, Buchanan, IA

Built 1984 Load: 46.8 t ADT: 8,850

FM

Fair

Over: SMALL STREAM

074052308, Louisa, IA

Built 1940 Load: 46.8 t ADT: 290

IA 146

Fair

Over: UP RR & WEST CREEK

0.1 mi. E of Jct. SR F62, Poweshiek, IA

Built 1986 Load: 46.8 t ADT: 2,210

6TH ST.

Fair

Over: CEDAR RIVER

CITY BRIDGE NO. 43, Black Hawk, IA

Built 1984 Load: 46.9 t ADT: 5,195

WB US 30

Fair

Over: PLEASANT RUN

1.8 mi. W of Jct US 151, Linn, IA

Built 1975 Load: 46.9 t ADT: 11,750

LOCAL

Fair

Over: BLACK CAT CREEK

098310901, Emmet, IA

Built 1985 Load: 47.0 t ADT: 20

LOCAL

Fair

Over: D D #40

099320602, Emmet, IA

Built 1978 Load: 47.0 t ADT: 15

LOCAL RD

Fair

Over: BR SPRUCE CREEK

087E43603, Jackson, IA

Built 1998 Load: 47.0 t ADT: 499

FM

Fair

Over: CREEK

080E33607, Scott, IA

Built 1956 Load: 47.0 t ADT: 4,750

FM

Fair

Over: SMALL STREAM

079383404, Shelby, IA

Built 1996 Load: 47.0 t ADT: 60

FM POLE RD

Fair

Over: CREEK

072302002, Union, IA

Built 1954 Load: 47.0 t ADT: 568

HEARST RD

Fair

Over: TRIB TO DRY RUN CREEK

89-14-33-02-10, Black Hawk, IA

Built 1978 Load: 47.1 t ADT: 33

MARKET AVE

Fair

Over: CREEK

086392902, Ida, IA

Built 2000 Load: 47.1 t ADT: 26

LOCAL

Fair

Over: CREEK

084E21104, Jackson, IA

Built 2004 Load: 47.1 t ADT: 15

BUFFALO RD

Fair

Over: WALNUT CREEK

078250300, Polk, IA

Built 1991 Load: 47.1 t ADT: 727

LOCAL

Fair

Over: BLUE CREEK

086092303, Benton, IA

Built 1985 Load: 47.2 t ADT: 5

IA 4 & IA 175

Fair

Over: CEDAR CREEK

2.2 mi. E of N jct SR N65, Calhoun, IA

Built 1993 Load: 47.2 t ADT: 1,040

US 18 EB

Fair

Over: CERRO GORDO COUNTY TRAIL

5.0 mi. E of Jct. I-35, Cerro Gordo, IA

Built 1997 Load: 47.2 t ADT: 4,450

IA 136

Fair

Over: BR DURIEN CREEK

0.1 mi. N of SR D39, Dubuque, IA

Built 1985 Load: 47.2 t ADT: 2,520

FM

Fair

Over: BATTLE CREEK

087410102, Ida, IA

Built 1968 Load: 47.2 t ADT: 499

FM

Fair

Over: SPRING CREEK

078232407, Polk, IA

Built 1978 Load: 47.2 t ADT: 649

210TH STREET

Fair

Over: SMALL

069293101, Ringgold, IA

Built 1945 Load: 47.2 t ADT: 120

IA 150

Fair

Over: CEDAR RIVER

1.0 mi. South of SR E16, Benton, IA

Built 1980 Load: 47.3 t ADT: 3,840

FM 165 ST

Fair

Over: SMALL STREAM

089060303, Delaware, IA

Built 1970 Load: 47.3 t ADT: 825

LOCAL 30TH ST

Fair

Over: BEAVER CREEK

090203601, Franklin, IA

Built 1983 Load: 47.3 t ADT: 16

SB I-29

Fair

Over: BOYER RIVER

3.0 mi. S of Jct. US 30, Harrison, IA

Built 1958 Load: 47.3 t ADT: 10,050

FM

Fair

Over: SMALL STREAM

089412401, Ida, IA

Built 1974 Load: 47.3 t ADT: 210

LOCAL

Fair

Over: CREEK

084E61403, Jackson, IA

Built 2001 Load: 47.3 t ADT: 26

LOCAL

Fair

Over: SMALL STREAM

075042203, Louisa, IA

Built 1985 Load: 47.3 t ADT: 62

SB US 151

Fair

Over: CRAB APPLE CREEK

2.9 MI. N OF N JCT. IA 13, Linn, IA

Built 1992 Load: 47.4 t ADT: 7,000

US 34

Fair

Over: CEDAR CREEK

4.4 mi. W of jct. IA 5, Monroe, IA

Built 1964 Load: 47.5 t ADT: 2,250

EB US 20

Fair

Over: PINE CREEK

1.6 mi. W of jct. SR W40, Buchanan, IA

Built 1978 Load: 47.6 t ADT: 4,150

EB US 20

Fair

Over: OVER ABANDON RR

0.4 MI W OF JCT IOWA #38, Delaware, IA

Built 1974 Load: 47.6 t ADT: 4,250

I-280

Fair

Over: LAKE OVERFLOW

1.1 mi. W of Jct. US 61, Scott, IA

Built 1972 Load: 47.6 t ADT: 24,200

WB US 20

Fair

Over: OVER ABANDON RR

0.1 mi E of SR D25, Woodbury, IA

Built 1978 Load: 47.6 t ADT: 12,750

OVERPASS DR

Fair

Over: CC RR

000000000, Hamilton, IA

Built 1931 Load: 47.7 t ADT: 3,353

LOC 350TH ST

Fair

Over: DRAINAGE DITCH #7

098273301, Kossuth, IA

Built 1990 Load: 47.7 t ADT: 15

LOCAL

Fair

Over: LINN CR

084193101, Marshall, IA

Built 1989 Load: 47.7 t ADT: 41

FM

Fair

Over: BLACKHAWK CREEK ,BRANCH

087160102, Grundy, IA

Built 1966 Load: 47.8 t ADT: 579

Showing 8,501-8,550 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.