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

HIGHWAY S-74 S

Fair

Over: REASONER CREEK

78191102, Jasper, IA

Built 1996 Load: 45.4 t ADT: 810

LOC 290TH ST

Fair

Over: LINDNER CREEK

097273201, Kossuth, IA

Built 1992 Load: 45.4 t ADT: 41

JAPPA RD.

Fair

Over: PLEASANT RUN

082060806, Linn, IA

Built 1997 Load: 45.4 t ADT: 1,061

LOCAL

Fair

Over: BR MINERVA CREEK

084190601, Marshall, IA

Built 1988 Load: 45.4 t ADT: 20

FM

Fair

Over: DEEP RIVER

079143502, Poweshiek, IA

Built 1997 Load: 45.4 t ADT: 640

FM

Fair

Over: PIKE RUN CREEK

099241502, Winnebago, IA

Built 1990 Load: 45.4 t ADT: 170

FM

Fair

Over: STREAM

092352802, Buena Vista, IA

Built 1996 Load: 45.5 t ADT: 559

IA 14

Fair

Over: BEAVER CREEK

0.2 mi. N of N jct. IA57, Butler, IA

Built 1984 Load: 45.5 t ADT: 1,760

KELLY AVE

Fair

Over: ROCK CREEK

082032602, Cedar, IA

Built 1989 Load: 45.5 t ADT: 26

US 59

Fair

Over: GREY CREEK OVERFLOW

0.2 mi. N SR C16, Cherokee, IA

Built 1986 Load: 45.5 t ADT: 1,460

IA 2

Fair

Over: WELDON RIVER

6.0 mi. E of E Jct US 69, Decatur, IA

Built 1984 Load: 45.5 t ADT: 1,330

LOCAL 70TH ST

Fair

Over: CRANE CREEK

099141201, Howard, IA

Built 1982 Load: 45.5 t ADT: 47

LOC 340TH ST

Fair

Over: BLACK CAT CREEK

097300501, Kossuth, IA

Built 2000 Load: 45.5 t ADT: 21

FM 185TH AVE

Fair

Over: DRAINAGE DITCH #90

099282416, Kossuth, IA

Built 1993 Load: 45.5 t ADT: 339

20TH AVE

Fair

Over: N FORK BUFFALO CREEK

098260406, Winnebago, IA

Built 1989 Load: 45.5 t ADT: 409

WINSLOW RD

Fair

Over: WEST FORK CEDAR RIVER

90-14-09-03, Black Hawk, IA

Built 2008 Load: 45.6 t ADT: 678

FM

Fair

Over: MUD CREEK

084112601, Benton, IA

Built 2003 Load: 45.7 t ADT: 200

IA 17

Fair

Over: PRAIRIE CREEK

2.4 MILES N OF JCT SR E26, Boone, IA

Built 1979 Load: 45.7 t ADT: 2,260

FM

Fair

Over: DD 198

086340102, Calhoun, IA

Built 1998 Load: 45.7 t ADT: 259

FS AREA ROAD

Fair

Over: LONG CREEK

APPROX. 3000' N. OF RD. I, Des Moines, IA

Built 1946 Load: 45.7 t ADT: 10

FM A-31

Fair

Over: DRAINAGE DITCH

099353401, Dickinson, IA

Built 1994 Load: 45.7 t ADT: 305

LOCAL

Fair

Over: ASHTON CREEK

089410202, Ida, IA

Built 1999 Load: 45.7 t ADT: 21

FM

Fair

Over: MILLER CREEK

078081902, Johnson, IA

Built 2001 Load: 45.7 t ADT: 600

IA 70

Fair

Over: DRAINAGE DITCH

0.4 MI. S OF JCT IOWA 22, Muscatine, IA

Built 1988 Load: 45.7 t ADT: 830

60TH AVE

Fair

Over: CREEK

080E23102, Scott, IA

Built 1998 Load: 45.7 t ADT: 1,280

EB US 20

Fair

Over: BUFFALO CREEK

2.3 MI. E OF JCT. SR W40, Buchanan, IA

Built 1978 Load: 45.8 t ADT: 3,500

LOCAL

Fair

Over: CREEK

085E50406, Jackson, IA

Built 2001 Load: 45.8 t ADT: 11

IA 14

Fair

Over: SO FK CHARITON RIVER

2.0 mi. S of S Jct SR J22, Wayne, IA

Built 1998 Load: 45.8 t ADT: 2,110

FM NE 46TH ST

Fair

Over: MUCHIKINOCK CREEK

080233402, Polk, IA

Built 1990 Load: 45.9 t ADT: 270

IA 175

Fair

Over: HONEY CREEK

1.5 MI. W OF W JCT US 65, Hardin, IA

Built 1991 Load: 46.0 t ADT: 1,300

US 65

Fair

Over: WHITE BREAST CREEK

1.3 MI. S OF U.S. 34, Lucas, IA

Built 1991 Load: 46.0 t ADT: 1,260

WHITE AVE

Fair

Over: OCHEYEDAN RIVER

098392702, Osceola, IA

Built 2009 Load: 46.0 t ADT: 509

172ND AVE

Fair

Over: CREEK

080E32506, Scott, IA

Built 1958 Load: 46.0 t ADT: 34

FM

Fair

Over: BIG SIOUX RIVER

096471803, Sioux, IA

Built 2009 Load: 46.0 t ADT: 1,277

LINCOLN WAY

Fair

Over: OVER UP RR

000000000, Story, IA

Built 1984 Load: 46.0 t ADT: 5,356

M66 BIRCH AVE

Fair

Over: NO NAME CREEK

084363202, Carroll, IA

Built 1965 Load: 46.1 t ADT: 34

190 TH

Fair

Over: STREAM

084321901, Greene, IA

Built 1991 Load: 46.1 t ADT: 30

FM

Fair

Over: JORDAN CREEK

074390302, Pottawattamie, IA

Built 1974 Load: 46.1 t ADT: 50

FM-WESTGATE RD

Fair

Over: NEOLA CREEK

077421307, Pottawattamie, IA

Built 1972 Load: 46.1 t ADT: 79

DESOTO AVENUE

Fair

Over: ALLEN CREEK

077440801, Pottawattamie, IA

Built 1970 Load: 46.1 t ADT: 289

FM

Fair

Over: WEST 102 RIVER

070341201, Taylor, IA

Built 1951 Load: 46.1 t ADT: 34

LOCAL

Fair

Over: ACKLEY CREEK

094181702, Floyd, IA

Built 1982 Load: 46.2 t ADT: 44

LOCAL RD

Fair

Over: STEWART CK

096171402, Floyd, IA

Built 1979 Load: 46.2 t ADT: 26

UPPR BOULDER RD

Fair

Over: BOULDER CREEK

086051601, Linn, IA

Built 1992 Load: 46.2 t ADT: 20

LOCAL

Fair

Over: SMALL

085131102, Tama, IA

Built 1965 Load: 46.2 t ADT: 20

LOCAL (LWC)

Fair

Over: BR BUCKEYE CREEK

082122302, Benton, IA

Built 1994 Load: 46.3 t ADT: 71

V14

Fair

Over: SMALL STREAM

095141302, Chickasaw, IA

Built 1957 Load: 46.3 t ADT: 550

FM 145 AVE

Fair

Over: SMALL STREAM

089061404, Delaware, IA

Built 1970 Load: 46.3 t ADT: 1,021

MILLVILLE RD

Fair

Over: STREAM

089013403, Dubuque, IA

Built 2017 Load: 46.3 t ADT: 20

FM

Fair

Over: STREAM

070212102, Wayne, IA

Built 1965 Load: 46.3 t ADT: 35

Showing 8,451-8,500 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.