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

LOCAL SEC RD

Fair

Over: BARRY CREEK

095392102, O'Brien, IA

Built 1900 Load: 32.4 t ADT: 41

FM

Fair

Over: DD JT 22

094341901, Palo Alto, IA

Built 1975 Load: 32.4 t ADT: 350

MERLE HAY RD

Fair

Over: BEAVER CREEK

000000000, Polk, IA

Built 1957 Load: 32.4 t ADT: 9,700

E HARTFORD AVE

Fair

Over: CREEK

078241300, Polk, IA

Built 1980 Load: 32.4 t ADT: 161

LOCAL

Fair

Over: CHEQUEST CREEK

069112205, Van Buren, IA

Built 1958 Load: 32.4 t ADT: 35

US 63 SB

Fair

Over: JEFFERSON PARK DD

1.0 M S of W jct of US 34, Wapello, IA

Built 2020 Load: 32.4 t ADT: 2,850

LOCAL

Fair

Over: SMALL STREAM

077091104, Washington, IA

Built 1965 Load: 32.4 t ADT: 26

US 20 EB

Fair

Over: ELLIOT CREEK

6.0 mi. W of jct. IA 140, Woodbury, IA

Built 2015 Load: 32.4 t ADT: 5,200

US 20 EB

Fair

Over: LITTLE SIOUX RIVER

0.4 mi. W of jct. IA 31, Woodbury, IA

Built 2017 Load: 32.4 t ADT: 3,250

IA 141

Fair

Over: WOLFE CREEK DITCH

2.0 mi. E of SR K64, Woodbury, IA

Built 1959 Load: 32.4 t ADT: 1,490

I 29 SB

Fair

Over: FLOYD RIVER

3.5 MI. N OF N JCT. US 75, Woodbury, IA

Built 2015 Load: 32.4 t ADT: 15,400

I 29 NB

Fair

Over: FLOYD RIVER

3.5 Mi. N of N Jct. US 75, Woodbury, IA

Built 2016 Load: 32.4 t ADT: 17,200

US 69

Fair

Over: IOWA RIVER

0.2 mi. S of Jct. SR C20, Wright, IA

Built 2022 Load: 32.4 t ADT: 3,020

W QUARRY RD

Fair

Over: ROCK CREEK

87-14-13-01-10, Black Hawk, IA

Built 1987 Load: 32.5 t ADT: 5

LOCAL

Fair

Over: SMALL STREAM

091160502, Butler, IA

Built 1900 Load: 32.5 t ADT: 26

FM 570TH ST

Fair

Over: WILLOW CREEK

091411901, Cherokee, IA

Built 1979 Load: 32.5 t ADT: 100

320TH AVE

Fair

Over: SMALL

083E42604, Clinton, IA

Built 1978 Load: 32.5 t ADT: 350

FM

Fair

Over: IOWA RIVER

087193303, Hardin, IA

Built 1976 Load: 32.5 t ADT: 79

LOCAL

Fair

Over: IOWA RIVER

088193113, Hardin, IA

Built 1977 Load: 32.5 t ADT: 51

FM

Fair

Over: IOWA RIVER

089193104, Hardin, IA

Built 1977 Load: 32.5 t ADT: 44

FM

Fair

Over: IOWA RIVER

089203406, Hardin, IA

Built 1979 Load: 32.5 t ADT: 79

LOCAL

Fair

Over: SMALL STREAM

088400702, Ida, IA

Built 1957 Load: 32.5 t ADT: 26

IA 1

Fair

Over: RALSTON CREEK

0.6 MI. N OF N JCT. US 6, Johnson, IA

Built 1932 Load: 32.5 t ADT: 13,500

LOCAL

Fair

Over: WHITEBREAST CREEK

073223211, Lucas, IA

Built 1978 Load: 32.5 t ADT: 47

NB I-29

Fair

Over: KEG CREEK

0.7 MI. S OF S JCT. US 34, Mills, IA

Built 1971 Load: 32.5 t ADT: 6,850

US 6 & IA 21

Fair

Over: ROCK CREEK

0.7 MI E OF W JCT IA 21, Poweshiek, IA

Built 1956 Load: 32.5 t ADT: 1,610

LOCAL 275TH ST

Fair

Over: SMITH CR

088083505, Buchanan, IA

Built 2002 Load: 32.6 t ADT: 26

LOCAL

Fair

Over: EAST WAPSIPINICON RIVER

096131002, Chickasaw, IA

Built 1995 Load: 32.6 t ADT: 51

420TH AVE.

Fair

Over: CREEK

082E63302, Clinton, IA

Built 1991 Load: 32.6 t ADT: 91

LOCAL

Fair

Over: CREEK

088251601, Hamilton, IA

Built 1926 Load: 32.6 t ADT: 20

LOCAL

Fair

Over: TRIB COAL CREEK

076133601, Keokuk, IA

Built 1979 Load: 32.6 t ADT: 15

US 34

Fair

Over: CRABAPPLE CREEK

3.1 MI. E OF US 59, Montgomery, IA

Built 1964 Load: 32.6 t ADT: 4,030

US 67

Fair

Over: PIGEON CREEK

4.1 mi. S of Jct. I-80, Scott, IA

Built 1995 Load: 32.6 t ADT: 9,800

IA 1

Fair

Over: ENGLISH RIVER

1.1 mi. S of Jct. IA 22, Washington, IA

Built 1979 Load: 32.6 t ADT: 4,120

D20 200TH ST

Fair

Over: BRUSHY CREEK

089272803, Webster, IA

Built 1979 Load: 32.6 t ADT: 2,453

LOCAL

Fair

Over: STREAM

074320801, Adair, IA

Built 1989 Load: 32.7 t ADT: 20

LOCAL

Fair

Over: MIDDLE NODAWAY RIVER

077332802, Adair, IA

Built 1978 Load: 32.7 t ADT: 21

IA 148

Fair

Over: STREAM

2.2 MI. S OF JCT. U.S. 34, Adams, IA

Built 1961 Load: 32.7 t ADT: 1,200

MULBERRY AVENUE

Fair

Over: LONZO CREEK

071333202, Adams, IA

Built 1978 Load: 32.7 t ADT: 26

CHESTNUT AVENUE

Fair

Over: LONG BRANCH

071353402, Adams, IA

Built 1988 Load: 32.7 t ADT: 20

190TH STREET

Fair

Over: WEST PLATTE RIVER

072322301, Adams, IA

Built 1988 Load: 32.7 t ADT: 34

LOCUST AVENUE

Fair

Over: STREAM

073331806, Adams, IA

Built 1965 Load: 32.7 t ADT: 11

110TH STREET

Fair

Over: STREAM

073350901, Adams, IA

Built 1979 Load: 32.7 t ADT: 5

LOCAL RD

Fair

Over: BR MISS RIVER

098030203, Allamakee, IA

Built 1978 Load: 32.7 t ADT: 294

LOCAL

Fair

Over: BR CLEAR CREEK

100052704, Allamakee, IA

Built 2001 Load: 32.7 t ADT: 26

FM

Fair

Over: BRANCH BEAR CREEK

100063004, Allamakee, IA

Built 2000 Load: 32.7 t ADT: 69

LOCAL

Fair

Over: PAINT CREEK

097051206, Allamakee, IA

Built 1997 Load: 32.7 t ADT: 39

LUSTER HEIGHTS RD

Fair

Over: SMALL STREAM

A00320470, Allamakee, IA

Built 2000 Load: 32.7 t ADT: 40

IA 26

Fair

Over: INDIAN CREEK

5.7 mi. N of Jct. IA 9, Allamakee, IA

Built 1935 Load: 32.7 t ADT: 1,540

LOCAL

Fair

Over: STREAM

069161304, Appanoose, IA

Built 1977 Load: 32.7 t ADT: 47

Showing 6,301-6,350 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.