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

FM

Fair

Over: STREAM

078142803, Poweshiek, IA

Built 1987 Load: 52.5 t ADT: 35

LOCAL (LWC)

Fair

Over: BRANCH PRAIRIE CREEK

082110401, Benton, IA

Built 1987 Load: 52.6 t ADT: 15

LOCAL (LWC)

Fair

Over: ROCK CREEK

086122601, Benton, IA

Built 1986 Load: 52.6 t ADT: 11

US 59

Fair

Over: GREY CREEK

1.1 mi. N of jct. SR C16, Cherokee, IA

Built 1986 Load: 52.6 t ADT: 1,460

IA 39

Fair

Over: SPANGLER CREEK

0.6 mi. N of N jct. E16, Crawford, IA

Built 1985 Load: 52.6 t ADT: 2,710

LOC RIVER ROAD

Fair

Over: BLACK CAT CREEK

096292404, Kossuth, IA

Built 1992 Load: 52.6 t ADT: 90

LOC 200TH AVE

Fair

Over: BUFFALO CREEK

097270502, Kossuth, IA

Built 1988 Load: 52.6 t ADT: 46

IA 16

Fair

Over: LITTLE LICK CREEK

1.7 mi. W of W jct. IA 1, Van Buren, IA

Built 1989 Load: 52.6 t ADT: 940

FM 270TH ST

Fair

Over: WILLOW CREEK

079433101, Harrison, IA

Built 1990 Load: 52.7 t ADT: 379

LOCAL RD

Fair

Over: SOUTH RIVER

074263401, Madison, IA

Built 1991 Load: 52.7 t ADT: 79

LOCAL

Fair

Over: BIG SLOUGH CREEK

077040401, Muscatine, IA

Built 1989 Load: 52.7 t ADT: 47

LOCAL

Fair

Over: LITTLE BEAR CREEK

080162403, Poweshiek, IA

Built 1982 Load: 52.7 t ADT: 120

LOCAL 170TH ST.

Fair

Over: PINE CREEK

089080801, Buchanan, IA

Built 2009 Load: 52.8 t ADT: 47

255TH ST

Fair

Over: BARBER CREEK

081E31905, Clinton, IA

Built 1991 Load: 52.8 t ADT: 21

FM

Fair

Over: DRY CREEK

083092101, Benton, IA

Built 1998 Load: 52.9 t ADT: 1,296

FM

Fair

Over: BEAR CREEK

084092604, Benton, IA

Built 1999 Load: 52.9 t ADT: 1,444

FM

Fair

Over: WILD CAT CREEK

084102502, Benton, IA

Built 1993 Load: 52.9 t ADT: 422

S CANFIELD RD

Fair

Over: INDIAN CREEK

88-11-17-02-10, Black Hawk, IA

Built 2003 Load: 52.9 t ADT: 678

POYNER RD

Fair

Over: SPRING CREEK

88-11-25-01-10, Black Hawk, IA

Built 1990 Load: 52.9 t ADT: 33

LOCAL

Fair

Over: BUFFALO CREEK

088070609, Buchanan, IA

Built 1998 Load: 52.9 t ADT: 51

FM

Fair

Over: PINE CREEK

088082105, Buchanan, IA

Built 1991 Load: 52.9 t ADT: 776

112TH ST

Fair

Over: BUCK CREEK

090100703, Buchanan, IA

Built 2001 Load: 52.9 t ADT: 25

FM

Fair

Over: OVERFLOW-BEAVER CK

090162702, Butler, IA

Built 1994 Load: 52.9 t ADT: 960

FM

Fair

Over: MIDDLE RACCOON RIVER

084350902, Carroll, IA

Built 1993 Load: 52.9 t ADT: 537

LOCAL

Fair

Over: BUCK CREEK

076370107, Cass, IA

Built 2005 Load: 52.9 t ADT: 537

340TH ST

Fair

Over: STONY CREEK

096370703, Clay, IA

Built 2003 Load: 52.9 t ADT: 185

330TH ST

Fair

Over: STREAM

096380601, Clay, IA

Built 2005 Load: 52.9 t ADT: 72

LOCAL

Fair

Over: BEAR CREEK

078283002, Dallas, IA

Built 1999 Load: 52.9 t ADT: 247

FM

Fair

Over: WELDON RIVER

068240504, Decatur, IA

Built 1993 Load: 52.9 t ADT: 15

180TH AVE

Fair

Over: LINDSEY CREEK

090053302, Delaware, IA

Built 2000 Load: 52.9 t ADT: 1,030

FM

Fair

Over: PRAIRIE CREEK

087E12304, Dubuque, IA

Built 1991 Load: 52.9 t ADT: 650

FM

Fair

Over: JOHNS CREEK

087011703, Dubuque, IA

Built 2001 Load: 52.9 t ADT: 130

FM

Fair

Over: CATFISH CREEK

088E21604, Dubuque, IA

Built 1998 Load: 52.9 t ADT: 450

GRAF RD

Fair

Over: LITTLE MAQUOKETA RIVER

089E13203, Dubuque, IA

Built 2006 Load: 52.9 t ADT: 560

N-70

Fair

Over: WILLOW CREEK

081321006, Guthrie, IA

Built 2004 Load: 52.9 t ADT: 428

FM

Fair

Over: GRITTER CREEK

078113204, Iowa, IA

Built 1988 Load: 52.9 t ADT: 60

ELLIS RD

Fair

Over: MORGAN CREEK

083081405, Linn, IA

Built 1996 Load: 52.9 t ADT: 1,403

C AVE N.E.

Fair

Over: DRY CREEK

084071510, Linn, IA

Built 1992 Load: 52.9 t ADT: 1,453

FM

Fair

Over: JONES CREEK

075262109, Madison, IA

Built 1990 Load: 52.9 t ADT: 826

FM

Fair

Over: WILLOW CREEK

094413601, O'Brien, IA

Built 2003 Load: 52.9 t ADT: 259

FM

Fair

Over: NORTH ENGLISH RIVER

079141402, Poweshiek, IA

Built 1997 Load: 52.9 t ADT: 640

FM

Fair

Over: KEG CREEK

078400603, Shelby, IA

Built 1982 Load: 52.9 t ADT: 50

LOCAL

Fair

Over: BIG WHISKEY CREEK

089462601, Woodbury, IA

Built 2004 Load: 52.9 t ADT: 50

FM

Fair

Over: CREEK

097163104, Floyd, IA

Built 1953 Load: 53.1 t ADT: 79

US 169

Fair

Over: BEAVER CREEK

0.9 MI. N OF JCT. IA 141, Dallas, IA

Built 1988 Load: 53.2 t ADT: 3,990

LOCAL

Fair

Over: STREAM

071102904, Jefferson, IA

Built 1968 Load: 53.2 t ADT: 60

IA 148

Fair

Over: SEVEN MILE CREEK

0.9 MI. S OF SR G-35, Cass, IA

Built 1994 Load: 53.3 t ADT: 790

FM

Fair

Over: WHITE WATER CREEK

088013511, Dubuque, IA

Built 1996 Load: 53.5 t ADT: 530

FM

Fair

Over: WHITE WATER CREEK

088013603, Dubuque, IA

Built 1996 Load: 53.5 t ADT: 530

FM

Fair

Over: CEDAR CREEK

076141201, Mahaska, IA

Built 2000 Load: 53.5 t ADT: 370

Showing 8,701-8,750 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.