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

WB US 20

Good

Over: PINE CREEK

1.6 mi. W of jct. SR W40, Buchanan, IA

Built 1978 Load: 47.6 t ADT: 4,150

310TH AVE

Good

Over: STREAM

090 03 15 04, Delaware, IA

Built 2014 Load: 47.6 t ADT: 88

US 275 & IA 2

Good

Over: STREAM

2.4 mi. N of S jct. IA 2, Fremont, IA

Built 1962 Load: 47.6 t ADT: 2,090

J34 220TH ST

Good

Over: MULE SLOUGH

068430705, Fremont, IA

Built 2018 Load: 47.6 t ADT: 210

222 ND

Good

Over: HARDIN CREEK

083300403, Greene, IA

Built 1987 Load: 47.6 t ADT: 62

FM

Good

Over: BEAR CREEK

084E13206, Jackson, IA

Built 2003 Load: 47.6 t ADT: 50

F28 MEHAFFEY BR RD

Good

Over: IOWA RIVER

32R6WT80N, Johnson, IA

Built 2015 Load: 47.6 t ADT: 5,100

LUCAS DR

Good

Over: STREAM

075180103, Marion, IA

Built 2017 Load: 47.6 t ADT: 35

E46 245TH ST

Good

Over: SOLDIER RIVER

083421707, Monona, IA

Built 2020 Load: 47.6 t ADT: 60

277TH AVE

Good

Over: MCCARTY CREEK

079E52706, Scott, IA

Built 2020 Load: 47.6 t ADT: 660

LOCAL

Good

Over: INDIAN CREEK

078373201, Shelby, IA

Built 2011 Load: 47.6 t ADT: 30

ADAMS-TAYLOR ST

Good

Over: NODAWAY RIVER DITCH

070350601, Taylor, IA

Built 2014 Load: 47.6 t ADT: 15

LOC 130TH AVE

Good

Over: STREAM

090060304, Delaware, IA

Built 1988 Load: 47.7 t ADT: 44

FM TIMBER AVE

Good

Over: HARTGRAVES CREEK

092192802, Franklin, IA

Built 2003 Load: 47.7 t ADT: 403

CHERRY GROVE RD

Good

Over: S FORK WALNUT CREEK

083041402, Jones, IA

Built 1988 Load: 47.7 t ADT: 44

FM 280TH ST

Good

Over: CALAMUS CREEK

096290401, Kossuth, IA

Built 1994 Load: 47.7 t ADT: 26

LOC 210TH AVE

Good

Over: MIDDLE BRANCH BLUE EARTH

099270902, Kossuth, IA

Built 1993 Load: 47.7 t ADT: 15

46OTH STREET

Good

Over: DRAINAGE

000000000, Pottawattamie, IA

Built 2010 Load: 47.7 t ADT: 50

IA 2

Good

Over: CHARITON RIVER

3.6 mi. E of Jct. IA 5, Appanoose, IA

Built 1983 Load: 47.8 t ADT: 2,830

US 218

Good

Over: STREAM

4.2 mi. S of Jct. U.S. 20, Black Hawk, IA

Built 2007 Load: 47.8 t ADT: 4,110

US 151 SB

Good

Over: N FORK MAQUOKETA RIVER

0.1 mi. N of Jct. IA 136, Dubuque, IA

Built 2002 Load: 47.8 t ADT: 4,550

LOCAL

Good

Over: STREAM

080162002, Poweshiek, IA

Built 1956 Load: 47.8 t ADT: 200

NB US 218

Good

Over: DAVIS CREEK

4.0 MI. S OF IA 22, Washington, IA

Built 1994 Load: 47.8 t ADT: 7,450

H AVE

Good

Over: GREEN BRIER CREEK

083312902, Greene, IA

Built 2004 Load: 47.9 t ADT: 11

IA 92

Good

Over: ST JOSEPHS CREEK

3.7 mi. E of Jct. SR T25, Mahaska, IA

Built 1979 Load: 47.9 t ADT: 3,240

ILLINOIS DR

Good

Over: STREAM

076182203, Marion, IA

Built 2017 Load: 47.9 t ADT: 135

FM

Good

Over: EAST NODAWAY RIVER

074312902, Adair, IA

Built 2005 Load: 48.0 t ADT: 71

LOCAL

Good

Over: NODAWAY RIVER

075321101, Adair, IA

Built 1997 Load: 48.0 t ADT: 51

LOCAL

Good

Over: PACKARD CREEK

067170207, Appanoose, IA

Built 2003 Load: 48.0 t ADT: 30

DYSART RD

Good

Over: MILLER CREEK

87-12-18-02-10, Black Hawk, IA

Built 2004 Load: 48.0 t ADT: 1,660

240TH ST

Good

Over: MIDDLE BEAVER CREEK

083281601, Boone, IA

Built 2021 Load: 48.0 t ADT: 26

FM

Good

Over: ELKHORN CREEK

085273603, Boone, IA

Built 1997 Load: 48.0 t ADT: 71

220TH ST

Good

Over: QUARTER SECTION RUN

0911302, Bremer, IA

Built 2007 Load: 48.0 t ADT: 49

LOCAL

Good

Over: FIELD STREAM

083342704, Carroll, IA

Built 2003 Load: 48.0 t ADT: 29

LOCAL

Good

Over: STORM CREEK

084341401, Carroll, IA

Built 1997 Load: 48.0 t ADT: 45

LOCAL

Good

Over: STORM CREEK

084342301, Carroll, IA

Built 2003 Load: 48.0 t ADT: 60

FM

Good

Over: MIDDLE RACOON RIVER

084350801, Carroll, IA

Built 2003 Load: 48.0 t ADT: 89

LOCAL-640TH ST

Good

Over: PIERSON CREEK

090422701, Cherokee, IA

Built 1996 Load: 48.0 t ADT: 26

LOCAL

Good

Over: CHARITON CR

071242404, Clarke, IA

Built 2004 Load: 48.0 t ADT: 15

LOCAL

Good

Over: WILLOW CREEK

083393008, Crawford, IA

Built 2005 Load: 48.0 t ADT: 26

FM

Good

Over: N CHEQUEST LAKE CREEK

070123308, Davis, IA

Built 1998 Load: 48.0 t ADT: 60

FM

Good

Over: PEE DEE CREEK

070152705, Davis, IA

Built 1997 Load: 48.0 t ADT: 50

140TH ST

Good

Over: LINDSEY CREEK

090052801, Delaware, IA

Built 2003 Load: 48.0 t ADT: 29

BIG HORN RD.

Good

Over: MINK CR

093071503, Fayette, IA

Built 2000 Load: 48.0 t ADT: 15

160 TH

Good

Over: EAST BUTTRICKS CREEK

084290601, Greene, IA

Built 2001 Load: 48.0 t ADT: 21

LOCAL

Good

Over: MOSQUITO CREEK

081302101, Guthrie, IA

Built 1993 Load: 48.0 t ADT: 40

110TH ST

Good

Over: BOONE RIVER

094263501, Hancock, IA

Built 2002 Load: 48.0 t ADT: 15

1110 220TH ST

Good

Over: W.BR. IOWA RIVER

095250201, Hancock, IA

Built 1993 Load: 48.0 t ADT: 81

LOC 910 250 ST

Good

Over: WEST BR IOWA RIVER

096252101, Hancock, IA

Built 2006 Load: 48.0 t ADT: 15

F50 270TH ST

Good

Over: ALLEN CREEK

079443501, Harrison, IA

Built 2021 Load: 48.0 t ADT: 379

Showing 15,501-15,550 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.