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

120TH ST

Good

Over: CREEK

083E61801, Clinton, IA

Built 2018 Load: 56.7 t ADT: 51

LCL-370TH ST

Good

Over: DEER CREEK

071402002, Mills, IA

Built 2005 Load: 56.7 t ADT: 15

C44 230TH ST

Good

Over: FLOYD RIVER

9146110310, Plymouth, IA

Built 2019 Load: 56.7 t ADT: 439

120TH ST.

Good

Over: SMALL STREAM

093171601, Butler, IA

Built 1985 Load: 56.8 t ADT: 30

LOCAL

Good

Over: IOWAY CREEK

086262101, Hamilton, IA

Built 1991 Load: 56.9 t ADT: 71

260TH ST

Good

Over: BRUSH BRANCH

075302501, Adair, IA

Built 2011 Load: 57.0 t ADT: 35

PK 678(VOLGA R)

Good

Over: FROG HOLLOW CREEK

IN VOLGA RIVER ST. PARK, Fayette, IA

Built 1984 Load: 57.0 t

US 20

Good

Over: STREAM

0.3 MILES E OF JCT IA 14, Grundy, IA

Built 1999 Load: 57.0 t ADT: 8,800

LOCAL

Good

Over: OUTLET CREEK

090362601, Buena Vista, IA

Built 2009 Load: 57.1 t ADT: 26

FM

Good

Over: EMIGRANT CREEK

084403001, Crawford, IA

Built 1986 Load: 57.1 t ADT: 50

NB US 61

Good

Over: SKUNK RIVER

0.5 mi. N of Jct. IA 16, Des Moines, IA

Built 1995 Load: 57.1 t ADT: 5,100

FM

Good

Over: THUNDER CREEK

077182706, Marion, IA

Built 1999 Load: 57.1 t ADT: 1,770

IA 14

Good

Over: TIMBER CREEK

1.2 MILES S OF JCT. US 30, Marshall, IA

Built 1992 Load: 57.1 t ADT: 4,250

US 63

Good

Over: LITTLE CEDAR CREEK

2.0 mi. S of Jct. IA 149, Wapello, IA

Built 2005 Load: 57.1 t ADT: 6,000

FM-YORK ROAD

Good

Over: WALNUT CREEK

077380201, Pottawattamie, IA

Built 2005 Load: 57.2 t ADT: 26

341ST ST

Good

Over: SMALL CREEK

087E42403, Jackson, IA

Built 2020 Load: 57.3 t ADT: 235

SQUAW CR.RD.

Good

Over: WANATEE CREEK

083062102, Linn, IA

Built 1999 Load: 57.3 t ADT: 618

235TH STREET

Good

Over: CHERRY CREEK

081E41203, Clinton, IA

Built 2007 Load: 57.4 t ADT: 82

E 110TH ST S

Good

Over: SLATER CREEK

079173104, Jasper, IA

Built 1999 Load: 57.5 t ADT: 20

US 218 SB

Good

Over: SUGAR CREEK

0.1 mi. S of Jct. IA 16, Lee, IA

Built 2003 Load: 57.5 t ADT: 4,550

FM C-38

Good

Over: WESTFIELD CREEK

092493601, Plymouth, IA

Built 1987 Load: 57.5 t ADT: 589

KOBER RD

Good

Over: TRIB TO WOLF CREEK

87-12-35-02-20, Black Hawk, IA

Built 2002 Load: 57.7 t ADT: 59

265TH AVE

Good

Over: SUGAR CREEK

083E30206, Clinton, IA

Built 2018 Load: 57.7 t ADT: 33

HILTON AVE

Good

Over: BIKE TRAIL

091130804, Bremer, IA

Built 1995 Load: 57.8 t ADT: 137

320TH

Good

Over: ROCK FALLS CREEK

097191601, Cerro Gordo, IA

Built 2008 Load: 57.8 t ADT: 51

150TH ST.

Good

Over: DEEP CREEK

083E33203, Clinton, IA

Built 2005 Load: 57.8 t ADT: 16

LOCAL

Good

Over: BR MUD CREEK

084111801, Benton, IA

Built 2001 Load: 57.9 t ADT: 15

ABBE HILLS RD

Good

Over: TURTLE CREEK

082050303, Linn, IA

Built 1993 Load: 57.9 t ADT: 118

ABBE VIEW RD

Good

Over: ABBE CREEK

082050507, Linn, IA

Built 2003 Load: 57.9 t ADT: 34

LIGHT RD

Good

Over: WEST SPRING CREEK

082052201, Linn, IA

Built 2004 Load: 57.9 t ADT: 49

LIGHT RD

Good

Over: SPRING CREEK

082052305, Linn, IA

Built 1998 Load: 57.9 t ADT: 79

STANDING ROCK R

Good

Over: SPRING CREEK

082052308, Linn, IA

Built 1992 Load: 57.9 t ADT: 29

GREEN RIDGE RD

Good

Over: SPRING CR

082052408, Linn, IA

Built 1998 Load: 57.9 t ADT: 128

IVANHOE RD

Good

Over: DILLS RUN

082053004, Linn, IA

Built 2006 Load: 57.9 t ADT: 255

SAILOR RD

Good

Over: TRIB TO CLEAR CREEK

082053505, Linn, IA

Built 2002 Load: 57.9 t ADT: 34

SMYTH RD

Good

Over: ABBE CREEK

082060108, Linn, IA

Built 1998 Load: 57.9 t ADT: 98

SPANISH RD

Good

Over: HOOSIER CREEK

082072502, Linn, IA

Built 2008 Load: 57.9 t ADT: 137

BEVERLY RD

Good

Over: BOWLING BALL CR

082080207, Linn, IA

Built 2003 Load: 57.9 t ADT: 2,013

TISSEL HOLLOWRD

Good

Over: TISSEL HOLLOW CREEK

000000000, Linn, IA

Built 2009 Load: 57.9 t ADT: 108

BOLTON MANOR RD

Good

Over: SIMMONS CREEK

083050401, Linn, IA

Built 2002 Load: 57.9 t ADT: 70

PARALTA RD

Good

Over: SIMMONS CREEK

083050511, Linn, IA

Built 1993 Load: 57.9 t ADT: 79

YEISLEY RD

Good

Over: ELBOW CREEK

083051004, Linn, IA

Built 2000 Load: 57.9 t ADT: 29

LINN GROVE RD

Good

Over: ELBOW CREEK

083051102, Linn, IA

Built 1990 Load: 57.9 t ADT: 88

ELBOW CR RD

Good

Over: ELBOW CR

083051005, Linn, IA

Built 2000 Load: 57.9 t ADT: 78

HORN RD

Good

Over: ALLEN CREEK

083053002, Linn, IA

Built 2003 Load: 57.9 t ADT: 39

BALLARD RD

Good

Over: ALLEN CREEK

083053004, Linn, IA

Built 1994 Load: 57.9 t ADT: 59

YOUNG RD

Good

Over: LONE TREE CR

083080508, Linn, IA

Built 2002 Load: 57.9 t ADT: 59

SUMMER ST

Good

Over: CROWS CREEK

084051307, Linn, IA

Built 2005 Load: 57.9 t ADT: 29

ALDERMAN RD

Good

Over: EAST BIG CREEK

084052202, Linn, IA

Built 1993 Load: 57.9 t ADT: 88

BURR OAKS RD

Good

Over: BIG CREEK

084053005, Linn, IA

Built 2004 Load: 57.9 t ADT: 98

Showing 16,201-16,250 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.