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

KOSSUTH AVE

Good

Over: STREAM

089430402, Woodbury, IA

Built 2019 Load: 28.1 t ADT: 20

VICTOR AVE

Good

Over: STREAM

76301508, Adair, IA

Built 2013 Load: 28.2 t ADT: 41

MOLINE RD

Good

Over: VIRDEN CREEK

89-12-07-02-10, Black Hawk, IA

Built 1983 Load: 28.2 t ADT: 79

270TH ST

Good

Over: WAPSIPINICON RVR OVRFLW

091113203, Bremer, IA

Built 2018 Load: 28.2 t ADT: 20

US 218

Good

Over: TRIB TO SHELL ROCK RIVER

2.0 MI. S JCT. IOWA #3, Bremer, IA

Built 1996 Load: 28.2 t ADT: 9,700

US 30

Good

Over: STREAM

0.3 mi. W of W jct SR M68, Carroll, IA

Built 1997 Load: 28.2 t ADT: 3,670

B45

Good

Over: UNAMED CREEK

AT JCT. US 18 & SR B45, Clayton, IA

Built 1988 Load: 28.2 t ADT: 10

LOVERS LANE

Good

Over: CREEK

090E20905, Dubuque, IA

Built 2019 Load: 28.2 t ADT: 45

80TH ST.

Good

Over: VOLGA RIVER

092093601, Fayette, IA

Built 1983 Load: 28.2 t ADT: 49

US 18

Good

Over: DRAINAGE DITCH

0.3 mi. W of Jct. SR T24, Floyd, IA

Built 1998 Load: 28.2 t ADT: 10,700

FM

Good

Over: SO FK MAQUOKETA RIVER

084E21318, Jackson, IA

Built 1999 Load: 28.2 t ADT: 1,730

OLIVE AVE

Good

Over: MUD CREEK

094420102, O'Brien, IA

Built 2012 Load: 28.2 t ADT: 41

FM

Good

Over: JOHNSON CREEK

095412001, O'Brien, IA

Built 2000 Load: 28.2 t ADT: 50

LOCAL

Good

Over: SO BR LITTLE FLOYD RIVER

096410802, O'Brien, IA

Built 2001 Load: 28.2 t ADT: 46

FM

Good

Over: SMALL UN-NAMED CREEK

097391002, O'Brien, IA

Built 1988 Load: 28.2 t ADT: 509

120TH ST

Good

Over: MINK CREEK

093461701, Plymouth, IA

Built 1999 Load: 28.2 t ADT: 50

LOCAL

Good

Over: STREAM

089383002, Sac, IA

Built 2002 Load: 28.2 t ADT: 11

FM

Good

Over: W. NISNABOTNA RIVER

079380407, Shelby, IA

Built 2003 Load: 28.2 t ADT: 71

US 69

Good

Over: SKINAWAY CREEK

0.3 mi. S of SR G76, Warren, IA

Built 1987 Load: 28.2 t ADT: 1,210

FM

Good

Over: STREAM

067200601, Wayne, IA

Built 2000 Load: 28.2 t ADT: 50

LOCAL

Good

Over: CLARK BRANCH

074330503, Adair, IA

Built 1997 Load: 28.3 t ADT: 46

US 63

Good

Over: TRIB TO WAPSIPINICON

0.3 mi. S of S Jct US 18, Chickasaw, IA

Built 2001 Load: 28.3 t ADT: 4,970

LOCAL

Good

Over: CREEK

087201104, Hardin, IA

Built 2001 Load: 28.3 t ADT: 16

510TH LANE

Good

Over: BR OF LITTLE WHITEBREAST

072210403, Lucas, IA

Built 2018 Load: 28.3 t ADT: 26

LOCAL

Good

Over: SMALL STREAM

071290202, Union, IA

Built 2004 Load: 28.3 t ADT: 46

FM

Good

Over: SMALL STREAM

072312603, Union, IA

Built 2003 Load: 28.3 t ADT: 89

YUKON AVE

Good

Over: BUCK CREEK

091113602, Bremer, IA

Built 2013 Load: 28.4 t ADT: 49

280TH ST

Good

Over: CREEK

081E13205, Clinton, IA

Built 2001 Load: 28.4 t ADT: 25

LOCAL

Good

Over: OCHEYDAN RIVER

098393401, Osceola, IA

Built 1941 Load: 28.4 t ADT: 35

BLUFF RD

Good

Over: LOST CREEK

080E52901, Scott, IA

Built 1985 Load: 28.4 t ADT: 1,060

LOCAL

Good

Over: CREEK

079362001, Audubon, IA

Built 1938 Load: 28.5 t ADT: 30

CARTER AVE

Good

Over: SMALL STREAM

089103304, Buchanan, IA

Built 2004 Load: 28.5 t ADT: 135

FM

Good

Over: BUCK CREEK

093031604, Clayton, IA

Built 1986 Load: 28.5 t ADT: 894

EP TRUE PKWY

Good

Over: CREEK

000000000, Dallas, IA

Built 2003 Load: 28.5 t ADT: 2,863

120TH ST

Good

Over: STOE CREEK

092101101, Fayette, IA

Built 2007 Load: 28.5 t ADT: 20

I-35

Good

Over: DRAINAGE DITCH

1.0 MI. N of SR C13, Franklin, IA

Built 1972 Load: 28.5 t ADT: 17,300

FM

Good

Over: TRULINER CREEK

093290906, Humboldt, IA

Built 1958 Load: 28.5 t ADT: 578

IA 38 & 64

Good

Over: BIG BEAR CREEK

0.8 MI. N OF S JCT. 64, Jones, IA

Built 1978 Load: 28.5 t ADT: 1,860

LOCAL

Good

Over: COLE CREEK

094410202, O'Brien, IA

Built 1998 Load: 28.5 t ADT: 35

FM

Good

Over: SMALL UN-NAMED CREEK

096391001, O'Brien, IA

Built 1998 Load: 28.5 t ADT: 240

330TH ST

Good

Over: SMALL UN-NAMED CREEK

096400101, O'Brien, IA

Built 2004 Load: 28.5 t ADT: 62

LOCAL

Good

Over: SMALL UN-NAMED CREEK

096400102, O'Brien, IA

Built 1991 Load: 28.5 t ADT: 50

SORREL AVE

Good

Over: DRY RUN

096403202, O'Brien, IA

Built 2017 Load: 28.5 t ADT: 21

FM

Good

Over: SKUNK RIVER

081223006, Polk, IA

Built 1973 Load: 28.5 t ADT: 967

E.46TH ST

Good

Over: GOOSE CREEK

000000000, Scott, IA

Built 1997 Load: 28.5 t ADT: 6,288

FRELON DRIVE

Good

Over: DRAINAGE DITCH

0.3 mi. S of SR C80, Woodbury, IA

Built 1998 Load: 28.5 t ADT: 1,291

230TH AVENUE

Good

Over: DEEP CREEK

083E33202, Clinton, IA

Built 2004 Load: 28.6 t ADT: 30

372ND AVE

Good

Over: SIMMONS CREEK

083E51004, Clinton, IA

Built 2002 Load: 28.6 t ADT: 26

FM

Good

Over: LITTLE CEDAR CREEK

069070702, Lee, IA

Built 1972 Load: 28.6 t ADT: 60

DEAN RD

Good

Over: TRIB TO PRAIRIE CREEK

000000000, Linn, IA

Built 2009 Load: 28.6 t ADT: 2,541

Showing 9,851-9,900 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.