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

EP TRUE PARKWAY

Fair

Over: JORDON CREEK

P27050490, Polk, IA

Built 1990 Load: 49.2 t ADT: 11,432

FM 450TH ST

Fair

Over: LITTLE SIOUX RIVER

093392103, Cherokee, IA

Built 1988 Load: 49.3 t ADT: 419

LOCAL

Fair

Over: DD

087220602, Hardin, IA

Built 1990 Load: 49.3 t ADT: 5

215TH ST.

Fair

Over: BRANCH OF SILVER CREEK

086041903, Jones, IA

Built 1940 Load: 49.3 t ADT: 15

US 18

Fair

Over: BLOODY RUN & RR

1.3 mi. W of Jct. IA. 76, Clayton, IA

Built 1988 Load: 49.4 t ADT: 4,140

IA 60 SB

Fair

Over: FLOYD RIVER TRIBUTARY

0.5 mi S of SR K64, Sioux, IA

Built 2003 Load: 49.4 t ADT: 3,200

LOCAL

Fair

Over: CREEK

081341702, Audubon, IA

Built 2008 Load: 49.5 t ADT: 46

LOC KENTUCKY AV

Fair

Over: SMALL STREAM

090092302, Buchanan, IA

Built 2002 Load: 49.5 t ADT: 41

310TH ST

Fair

Over: DEADBRIER CREEK

1.2 mi. east IA 4, Greene, IA

Built 1998 Load: 49.5 t ADT: 26

LOCAL

Fair

Over: ROCK CREEK

081172803, Jasper, IA

Built 2007 Load: 49.5 t ADT: 16

250TH ST

Fair

Over: SUGAR CREEK

080022003, Cedar, IA

Built 1989 Load: 49.6 t ADT: 45

LOCAL

Fair

Over: MOSQUITO CREEK

081303604, Guthrie, IA

Built 1993 Load: 49.8 t ADT: 11

US 52

Fair

Over: SPRUCE CREEK

3.2 mi. N of jct. IA 62, Jackson, IA

Built 1986 Load: 49.8 t ADT: 3,100

BEAR CREEK RD.

Fair

Over: BEAR CREEK

084012603, Jones, IA

Built 1988 Load: 49.8 t ADT: 47

W TAMA RD

Fair

Over: ROCK CREEK

87-14-35-01-10, Black Hawk, IA

Built 2003 Load: 49.9 t ADT: 560

LOCAL

Fair

Over: OVERFLOW LITTLE CEDAR

096152302, Floyd, IA

Built 1990 Load: 49.9 t ADT: 26

IA 27 SB

Fair

Over: DES MOINES RIVER

St. Francis Border Bridge, Lee, IA

Built 2002 Load: 49.9 t ADT: 3,600

IA 27 NB

Fair

Over: DES MOINES RIVER

St. Francis Border Bridge, Lee, IA

Built 2002 Load: 49.9 t ADT: 3,600

INDIAN BR.RD.

Fair

Over: INDAIN CREEK

085063201, Linn, IA

Built 1997 Load: 49.9 t ADT: 33

IA 21

Fair

Over: TRIBUTARY ENGLISH RIVER

3.1 mi. S of IA 85, Poweshiek, IA

Built 1985 Load: 49.9 t ADT: 1,490

FM

Fair

Over: DRY CREEK

083090101, Benton, IA

Built 1988 Load: 50.0 t ADT: 34

FM

Fair

Over: DRY CREEK

083091402, Benton, IA

Built 1999 Load: 50.0 t ADT: 1,444

LOCAL

Fair

Over: WILDCAT CREEK

084102602, Benton, IA

Built 1994 Load: 50.0 t ADT: 15

FM

Fair

Over: SMALL CREEK

090101605, Buchanan, IA

Built 1998 Load: 50.0 t ADT: 1,650

FM 200TH AVE

Fair

Over: WILLOW CREEK

094371102, Clay, IA

Built 1989 Load: 50.0 t ADT: 45

FM

Fair

Over: MOSQUITO CREEK

081302604, Guthrie, IA

Built 1999 Load: 50.0 t ADT: 270

FM

Fair

Over: SOUTH BIG CREEK

071050102, Henry, IA

Built 1996 Load: 50.0 t ADT: 940

FM

Fair

Over: COON CREEK

081111305, Iowa, IA

Built 1997 Load: 50.0 t ADT: 1,490

LOCAL

Fair

Over: PRICE CREEK

081092203, Iowa, IA

Built 1989 Load: 50.0 t ADT: 50

FM

Fair

Over: CRABAPPLE CREEK

072392903, Montgomery, IA

Built 1994 Load: 50.0 t ADT: 436

FM

Fair

Over: JACKSON CREEK

069212704, Wayne, IA

Built 2001 Load: 50.0 t ADT: 680

FM

Fair

Over: WINNEBAGO RIVER

100232103, Winnebago, IA

Built 2002 Load: 50.0 t ADT: 270

FLOYD LINE ST

Fair

Over: STREAM

093160301, Butler, IA

Built 1983 Load: 50.2 t ADT: 15

C 47 (95TH ST)

Fair

Over: IOWA RIVER

0.5 miles east of S13, Franklin, IA

Built 2012 Load: 50.2 t ADT: 560

LOCAL

Fair

Over: CREEK

086210502, Hardin, IA

Built 1988 Load: 50.2 t ADT: 15

LOCAL

Fair

Over: MINERVA CREEK

086222401, Hardin, IA

Built 1989 Load: 50.2 t ADT: 20

LOCAL

Fair

Over: TIPTON CREEK

087220102, Hardin, IA

Built 1988 Load: 50.2 t ADT: 29

LOCAL

Fair

Over: VAN ZANTE CREEK

077191102, Marion, IA

Built 1970 Load: 50.2 t ADT: 47

EB US 34

Fair

Over: KEG CREEK

0.2 mi. E of jct. SR L35, Mills, IA

Built 1969 Load: 50.2 t ADT: 3,650

IA 92

Fair

Over: DRAINAGE DITCH

3.3 mi. W of Jct. SR W38, Washington, IA

Built 1968 Load: 50.2 t ADT: 1,780

EB US 20

Fair

Over: PROPOSED RD.

0.5 mi W of IA 12, Woodbury, IA

Built 1978 Load: 50.2 t ADT: 13,850

GARDEN RD

Fair

Over: TRIB CHEQUEST CREEK

069102004, Van Buren, IA

Built 2004 Load: 50.3 t ADT: 11

IA 22

Fair

Over: ENGLISH RIVER OVERFLOW

2.5 mi. W of jct. IA 1, Washington, IA

Built 1994 Load: 50.6 t ADT: 3,330

IA 9

Fair

Over: LITTLE ROCK RIVER

1.0 mi. W of SR L26, Lyon, IA

Built 1987 Load: 50.7 t ADT: 1,730

WB US 20

Fair

Over: PROPOSED RD.

0.5 mi. W of IA 12, Woodbury, IA

Built 1978 Load: 50.7 t ADT: 13,850

V AVE

Fair

Over: W BEAVER CREEK

084292202, Greene, IA

Built 1988 Load: 50.8 t ADT: 30

100 TH

Fair

Over: SMALL

085320401, Greene, IA

Built 1978 Load: 50.8 t ADT: 45

LOCAL

Fair

Over: BR ELLIOTT CREEK

088460302, Woodbury, IA

Built 1980 Load: 50.8 t ADT: 40

LOCAL

Fair

Over: SPRING CREEK

094112602, Chickasaw, IA

Built 1990 Load: 50.9 t ADT: 51

FM

Fair

Over: CREEK

096132402, Chickasaw, IA

Built 1990 Load: 50.9 t ADT: 79

Showing 8,601-8,650 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.