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 77

Unknown

Over: MISSOURI RIVER & RD

IN SIOUX CITY, Woodbury, IA

Built 1981 ADT: 1,630

IA 12

Unknown

Over: RR,RVR, STS, & IA 376

0.1 mi W of Jct. IA 376, Woodbury, IA

Built 1936 ADT: 8,500

IA 376

Unknown

Over: CUNNINGHAM DR

1.1 mi S of jct IA 12, Woodbury, IA

Built 1978 ADT: 3,420

RAMP IA 12

Unknown

Over: RAMP OFF IA 12 TO IA 376

At EB IA 12 and SB US 376, Woodbury, IA

Built 1967 ADT: 680

IA 376 NB

Unknown

Over: BNSF UP RR-TAFT ST

0.1 MI. S. OF SR D12, Woodbury, IA

Built 2017 ADT: 1,470

SB IA 376

Unknown

Over: UP BNSF RR-TAFT ST

0.1 mi. S of SR D12, Woodbury, IA

Built 1974 ADT: 1,470

D51 (260TH ST)

Unknown

Over: I 29

At jct. I-29, Woodbury, IA

Built 2014 ADT: 19,300

I 29 NB

Unknown

Over: 8TH ST

2.0 MI.S.OF JCT. US 20, Woodbury, IA

Built 2014 ADT: 1,050

I 29 SB

Unknown

Over: FLOYD BLVD

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

Built 2019 ADT: 3,550

AVIATION BLVD

Unknown

Over: UP RR & HARBOR DR

000000000, Woodbury, IA

Built 2000 ADT: 690

US 20

Unknown

Over: IA 376 & UP RR

at jct of Ia. 376, Woodbury, IA

Built 1976 ADT: 11,600

US 20 RAMPS DF

Unknown

Over: RAMP OVER IA 376 & UP RR

3.8 mi. W of IA 12, Woodbury, IA

Built 1976 ADT: 11,600

US 20 RAMPS AG

Unknown

Over: RAMP OVER IA 376 & RR

At jct. IA 376, Woodbury, IA

Built 1976 ADT: 11,600

I 129

Unknown

Over: MISSOURI RIVER & I-29

0.5 MI.W.OF JCT.29, Woodbury, IA

Built 1976 ADT: 26,500

SB I29 TO EB 20

Unknown

Over: I 29

At the Jct of I-29, Woodbury, IA

Built 1976 ADT: 26,500

US 20 RAMP G

Unknown

Over: RAMP G OVER I-29

At the jct. of I-29, Woodbury, IA

Built 1976 ADT: 23,100

SO HILLS DR

Unknown

Over: US 20 & US 75

3.0 mi W of IA 12, Woodbury, IA

Built 1975 ADT: 28,000

LAKEPORT ST

Unknown

Over: US 20

1.5 mi. E of jct. I-29, Woodbury, IA

Built 1978 ADT: 20,100

EB US 20

Unknown

Over: SERGEANT ROAD

2.1 mi. W of Jct. IA 12, Woodbury, IA

Built 1978 ADT: 2,950

WB US 20

Unknown

Over: SERGEANT ROAD

2.1 mi. W of jct IA 12, Woodbury, IA

Built 1978 ADT: 2,950

EB US 20

Unknown

Over: SUNNYBROOK DR

1.7 mi. W of IA 12, Woodbury, IA

Built 1978 ADT: 4,200

WB US 20

Unknown

Over: SUNNYBROOK DR

1.7 mi. W of IA 12, Woodbury, IA

Built 1978 ADT: 4,200

MORNINGSIDE AVE

Unknown

Over: US 20

At Jct. SR D25, Woodbury, IA

Built 1978 ADT: 25,400

SB IA 12

Unknown

Over: US 20

At jct. U.S. 20/U.S. 75, Woodbury, IA

Built 1978 ADT: 8,100

NB IA 12

Unknown

Over: US 20 & US 75

At jct. US 20/US 75, Woodbury, IA

Built 1978 ADT: 8,100

CORRECTIONVILLE RD

Unknown

Over: US 75

1.7 mi. N of jct. IA 12, Woodbury, IA

Built 1998 ADT: 19,800

US 75 SB

Unknown

Over: OUTER DR

3.5 mi. N of Jct. IA 12, Woodbury, IA

Built 2000 ADT: 2,395

US 75 NB

Unknown

Over: OUTER DR

3.3 mi. N of Jct. IA 12, Woodbury, IA

Built 2000 ADT: 2,395

US 75 NB

Unknown

Over: STONE AVE

0.7 mi. N of jct. IA 12, Woodbury, IA

Built 1999 ADT: 150

US 75 SB

Unknown

Over: STONE AVE

0.7 mi. N of jct IA 12, Woodbury, IA

Built 1999 ADT: 150

US 75 NB

Unknown

Over: TAFT ST

5.5 mi. N of US 20/IA 12, Woodbury, IA

Built 1999 ADT: 870

US 75 SB

Unknown

Over: TAFT ST

5.5 mi. N of US 20/IA 12, Woodbury, IA

Built 1999 ADT: 870

US 75 SB

Unknown

Over: RAILROAD & RAMP

5.8 mi. N of IA 12, Woodbury, IA

Built 1999 ADT: 3,900

US 75 NB

Unknown

Over: BUS 75

5.8 mi. N of Jct. IA 12, Woodbury, IA

Built 1999 ADT: 3,900

OGDEN AVE/1ST

Unknown

Over: I-29

2.5 mi. S of N jct. US 75, Woodbury, IA

Built 2003 ADT: 18,900

WESLEY PKWY

Unknown

Over: TRI-VIEW & BNSF RR

At Jct. IA 12, Woodbury, IA

Built 2012 ADT: 4,640

I 29 SB

Unknown

Over: IA 12 SB VIRGINIA ST

0.8 MI. S OF JCT. US 77, Woodbury, IA

Built 2019 ADT: 1,665

I 29 NB

Unknown

Over: VIRGINIA ST

0.8 mi. S of jct. U.S. 77, Woodbury, IA

Built 2017 ADT: 1,665

I29NBNEBRASKASTRP

Unknown

Over: IA 12 & VIRGINIA ST

I-29 NEBRASKA ST. RAMP D, Woodbury, IA

Built 2017 ADT: 3,330

I 29 SB

Unknown

Over: PIERCE ST FRONTAGE RD

0.4 MI S. OF JCT. US 77, Woodbury, IA

Built 2018 ADT: 2,270

I 29 IA 12 NB

Unknown

Over: PIERCE ST FRONTAGE RD

0.4 MI. S OF JCT. US 77, Woodbury, IA

Built 2017 ADT: 2,270

I 29 NB IA 12 NB

Unknown

Over: HAMILTON BLVD

0.6 mi. N of US 77, Woodbury, IA

Built 2016 ADT: 1,400

SY RD A-38

Unknown

Over: I-35

At Jct. SR A38, Worth, IA

Built 1971 ADT: 18,900

FM RD A-39

Unknown

Over: I-35

3.0 MI. N OF JCT. IA #9, Worth, IA

Built 1970 ADT: 20,000

FM RD A-34

Unknown

Over: I-35

7.3 MI. N OF Jct. IA 9, Worth, IA

Built 1970 ADT: 19,100

A 27

Unknown

Over: I-35

2.0 mi. S of Jct. SR 105, Worth, IA

Built 1972 ADT: 19,100

SR 105

Unknown

Over: I-35

At Jct. S.R. 105, Worth, IA

Built 1972 ADT: 16,200

A 15

Unknown

Over: I-35

2.2 MI. N of Jct. SR 105, Worth, IA

Built 1972 ADT: 19,400

305TH ST

Unknown

Over: I-35

3.3 mi. N of Jct. SR R75, Wright, IA

Built 1974 ADT: 16,200

FM R-75

Unknown

Over: I-35

AT SEC. RD. R75, Wright, IA

Built 1971 ADT: 15,900

Showing 1,001-1,050 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.