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

325TH ST

Good

Over: REYNOLDS CREEK

86422905, Woodbury, IA

Built 2015 Load: 39.9 t ADT: 40

GLEN ELLEN RD

Good

Over: DRAINAGE DITCH

0884721, Woodbury, IA

Built 2012 Load: 39.9 t ADT: 170

US 75

Good

Over: STREAM

1.2 mi. N of S.R. D12, Woodbury, IA

Built 1999 Load: 39.9 t ADT: 18,200

LOCAL

Good

Over: D.D. 107

093250401, Wright, IA

Built 2010 Load: 39.9 t ADT: 15

220TH ST

Good

Over: STREAM

075320601, Adair, IA

Built 2009 Load: 40.0 t ADT: 30

FM

Good

Over: CREEK

000000000, Audubon, IA

Built 2010 Load: 40.0 t ADT: 34

FM

Good

Over: CREEK

081342502, Audubon, IA

Built 1932 Load: 40.0 t ADT: 15

E DUNKERTON RD

Good

Over: ELK RUN CREEK

90-12-34-01-10, Black Hawk, IA

Built 1984 Load: 40.0 t ADT: 1,512

W35 QUASQUETON AVE

Good

Over: SMALL STREAM

087081502, Buchanan, IA

Built 2019 Load: 40.0 t ADT: 1,159

LOCAL 275TH ST

Good

Over: SPRING CR

088103105, Buchanan, IA

Built 2010 Load: 40.0 t ADT: 25

FM

Good

Over: LITTLE WAPSIPINICON

090101705, Buchanan, IA

Built 1996 Load: 40.0 t ADT: 1,650

LOCAL

Good

Over: HARTGRAVE CREEK

092183002, Butler, IA

Built 2000 Load: 40.0 t ADT: 59

YARROW

Good

Over: COLD WATER CREEK

94193625, Cerro Gordo, IA

Built 2011 Load: 40.0 t ADT: 206

FM

Good

Over: LITTLE SIOUX RVR W FORK

091421502, Cherokee, IA

Built 2008 Load: 40.0 t ADT: 838

FM

Good

Over: HARTS MILL CREEK

081E60501, Clinton, IA

Built 1962 Load: 40.0 t ADT: 1,310

100TH STREET

Good

Over: PRAIRIE CREEK

083E20201, Clinton, IA

Built 2006 Load: 40.0 t ADT: 11

120TH ST.

Good

Over: BAIRD CREEK

083E50708, Clinton, IA

Built 2008 Load: 40.0 t ADT: 104

FM

Good

Over: RUNNING SLOUGH DRAIN

071011703, Des Moines, IA

Built 2001 Load: 40.0 t ADT: 80

US 151 SB

Good

Over: WHITEWATER CREEK

1.8 mi. S of Jct. SR D53, Dubuque, IA

Built 2003 Load: 40.0 t ADT: 4,650

150 TH

Good

Over: DEVILS FORK

085293301, Greene, IA

Built 1979 Load: 40.0 t ADT: 21

LOCAL ROAD

Good

Over: BEAVER CREEK

089171501, Grundy, IA

Built 2003 Load: 40.0 t ADT: 33

LOCAL

Good

Over: MASON CREEK

079322608, Guthrie, IA

Built 2009 Load: 40.0 t ADT: 20

FM

Good

Over: BAYS BRANCH CREEK

080302203, Guthrie, IA

Built 2008 Load: 40.0 t ADT: 60

312TH ST

Good

Over: MUD CREEK

070052203, Henry, IA

Built 2011 Load: 40.0 t ADT: 80

LOCAL ROAD

Good

Over: GREEN CREEK

072072107, Henry, IA

Built 2010 Load: 40.0 t ADT: 35

F 62 (520TH ST)

Good

Over: BIG SLOUGH CR

F62 7.5 mi. east of Hills, Johnson, IA

Built 2012 Load: 40.0 t ADT: 760

JOHNSON-IOWA RD

Good

Over: DEER CREEK

078080704, Johnson, IA

Built 2019 Load: 40.0 t ADT: 170

127TH AVE

Good

Over: BRUSH CREEK

072232108, Lucas, IA

Built 2008 Load: 40.0 t ADT: 25

US 169

Good

Over: CLANTON CREEK

1.1 MI. N OF SR G61, Madison, IA

Built 1976 Load: 40.0 t ADT: 1,890

FM

Good

Over: WALNUT CREEK

75183200, Marion, IA

Built 2009 Load: 40.0 t ADT: 1,280

NEST AVE

Good

Over: LAMKIN CREEK

09642090201, O'Brien, IA

Built 2014 Load: 40.0 t ADT: 46

FM

Good

Over: MUD CREEK

090451203, Plymouth, IA

Built 2008 Load: 40.0 t ADT: 409

220TH ST

Good

Over: JOHN'S CREEK

091440101, Plymouth, IA

Built 2008 Load: 40.0 t ADT: 30

FM

Good

Over: SMALL STREAM

091471101, Plymouth, IA

Built 1987 Load: 40.0 t ADT: 259

160TH ST

Good

Over: BIG WHISKEY SLOUGH

9243020110, Plymouth, IA

Built 2015 Load: 40.0 t ADT: 34

IRIS AVE

Good

Over: MINK CREEK

000000000, Plymouth, IA

Built 2009 Load: 40.0 t ADT: 30

LOCAL

Good

Over: N ENGLISH RIVER

079151402, Poweshiek, IA

Built 2008 Load: 40.0 t ADT: 26

247TH AVE

Good

Over: CREEK

079E50704, Scott, IA

Built 2019 Load: 40.0 t ADT: 50

LOCAL

Good

Over: NO NAME CREEK

094441601, Sioux, IA

Built 2011 Load: 40.0 t ADT: 219

LOCAL

Good

Over: SMALL

094453402, Sioux, IA

Built 2009 Load: 40.0 t ADT: 11

K 52 (IBEX AVE)

Good

Over: CREEK

095452502, Sioux, IA

Built 2013 Load: 40.0 t ADT: 150

65TH AVE

Good

Over: BRANCH SOUTH RIVER

075252506, Warren, IA

Built 2016 Load: 40.0 t ADT: 11

107TH ST

Good

Over: CREEK

0.5 Mi W of 180 Av, Winneshiek, IA

Built 2016 Load: 40.0 t ADT: 15

MONROE AVE

Good

Over: STREAM

0.5 mi N of G35 on Monroe, Adair, IA

Built 2019 Load: 40.1 t ADT: 30

RAMP D (NB)

Good

Over: OVERFLOW

0.2 MI. N JCT. IA #57, Black Hawk, IA

Built 1995 Load: 40.1 t ADT: 5,100

LOCAL

Good

Over: SMALL STREAM

090181501, Butler, IA

Built 1992 Load: 40.1 t ADT: 30

SPRING AVE

Good

Over: STREAM

092153102, Butler, IA

Built 1991 Load: 40.1 t ADT: 29

FM - LANSING

Good

Over: WATERWAY

076363101, Cass, IA

Built 1997 Load: 40.1 t ADT: 34

120TH STREET

Good

Over: SIMMONS CREEK

083E51601, Clinton, IA

Built 1993 Load: 40.1 t ADT: 62

F58 296TH ST

Good

Over: MOSQUITO CREEK

025500525, Harrison, IA

Built 2016 Load: 40.1 t ADT: 121

Showing 14,201-14,250 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.