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

305TH TRAIL

Good

Over: STREAM

078310903, Guthrie, IA

Built 2017 Load: 60.9 t ADT: 20

US 20

Good

Over: DRAINAGE DITCH #4

0.7 MILE E OF JCT US 69, Hamilton, IA

Built 1968 Load: 61.6 t ADT: 9,600

LOCAL

Good

Over: STEELE CREEK

069230501, Wayne, IA

Built 2005 Load: 61.7 t ADT: 20

US 75

Good

Over: STREAM

1.3 mi N of jct IA 10, Sioux, IA

Built 1998 Load: 61.8 t ADT: 7,300

344TH AVE

Good

Over: SMALL CREEK

084E41606, Jackson, IA

Built 2019 Load: 61.9 t ADT: 15

M16 380TH STREET

Good

Over: STREAM

076400402, Pottawattamie, IA

Built 2021 Load: 61.9 t ADT: 289

US 6

Good

Over: CLEAR CREEK

0.3 mi. W of Jct. 1st Ave, Johnson, IA

Built 1998 Load: 62.0 t ADT: 26,600

I-35

Good

Over: DRAINAGE DITCH

1.2 MILES N OF JCT SR E15, Story, IA

Built 1967 Load: 62.2 t ADT: 27,900

120TH AVE

Good

Over: CREEK

082E13302, Clinton, IA

Built 2022 Load: 62.5 t ADT: 35

SB US 218

Good

Over: SINK CREEK

0.7 mi S of jct US20/I380, Black Hawk, IA

Built 1983 Load: 62.6 t ADT: 6,050

185TH PLACE

Good

Over: STREAM

075193604, Marion, IA

Built 2018 Load: 62.6 t ADT: 145

155TH AVE

Good

Over: STREAM

077190906, Marion, IA

Built 2011 Load: 62.7 t ADT: 11

LOCAL

Good

Over: STREAM

077212901, Marion, IA

Built 2006 Load: 62.7 t ADT: 73

STREETER RD

Good

Over: TRIB TO CEDAR RIVER

90-13-16-02-10, Black Hawk, IA

Built 1999 Load: 62.9 t ADT: 79

LOCAL RD

Good

Over: CLEGHORN DD

083450703, Monona, IA

Built 2002 Load: 62.9 t ADT: 319

FM

Good

Over: BEAMAN CREEK

085371401, Crawford, IA

Built 1958 Load: 63.1 t ADT: 468

LINN BENTON RD

Good

Over: BR OF BLUE CREEK

086081802, Linn, IA

Built 2018 Load: 63.2 t ADT: 25

LOCAL

Good

Over: EAST NODAWAY RIVER

074313201, Adair, IA

Built 2002 Load: 63.5 t ADT: 46

HESS RD

Good

Over: TRIB TO MILLER CREEK

87-13-36-02-05, Black Hawk, IA

Built 2002 Load: 63.8 t ADT: 5

J14 102ND ST

Good

Over: STREAM

070360503, Page, IA

Built 2016 Load: 63.8 t ADT: 50

G26 190TH ST

Good

Over: SMALL STREAM

76092301, Washington, IA

Built 2015 Load: 63.8 t ADT: 640

110TH ST.

Good

Over: UNION CREEK

083E30703, Clinton, IA

Built 1992 Load: 64.1 t ADT: 73

170TH ST

Good

Over: DRAINAGE DITCH

071012901, Des Moines, IA

Built 2018 Load: 64.2 t ADT: 47

G 15 (140TH ST)

Good

Over: MIDDLE NODAWAY RIVER

77332870, Adair, IA

Built 2012 Load: 64.4 t ADT: 60

GRUNDY RD

Good

Over: TRIB TO BEAVER CREEK

89-14-20-02-10, Black Hawk, IA

Built 1997 Load: 64.5 t ADT: 59

IA 44

Good

Over: ELM CREEK

0.2 mi. E of Jct. SR M47, Shelby, IA

Built 1988 Load: 64.5 t ADT: 1,490

290TH AVE.

Good

Over: SMALL STREAM

083E42902, Clinton, IA

Built 2003 Load: 64.7 t ADT: 70

215TH STREET

Good

Over: CREEK

082E43303, Clinton, IA

Built 1964 Load: 64.8 t ADT: 550

291ST AVE

Good

Over: CREEK

087E30104, Jackson, IA

Built 2017 Load: 64.8 t ADT: 44

FOREST HOME RD

Good

Over: STREAM

078153003, Poweshiek, IA

Built 2021 Load: 65.2 t ADT: 60

EVERGREEN AVE

Good

Over: JOHNSON CREEK

091183504, Butler, IA

Built 2010 Load: 65.4 t ADT: 30

185TH ST

Good

Over: DRY CREEK

092161803, Butler, IA

Built 2010 Load: 65.4 t ADT: 10

W BLUE RD

Good

Over: WEST BLUE CREEK

W Blue Rd, T86N, R8W, 30, Linn, IA

Built 2010 Load: 65.4 t ADT: 70

US 218

Good

Over: BLOODY RUN

5.7 miles S Jct. IA 14, Floyd, IA

Built 1999 Load: 65.8 t ADT: 10,000

160TH ST

Good

Over: SOUTH BRANCH ELK RIVER

082E60601, Clinton, IA

Built 2021 Load: 66.1 t ADT: 25

US 52 SB RAMP LOOP

Good

Over: GRANGER CREEK

1.5 MI. S OF DUBUQUE, Dubuque, IA

Built 2019 Load: 66.1 t ADT: 1,770

IA 141

Good

Over: SIMMONS CREEK

0.8 Mi W of W Jct. IA175, Monona, IA

Built 2014 Load: 66.1 t ADT: 1,880

IA 149

Good

Over: STREAM

0.7 mi. N of Jct. SR F52, Iowa, IA

Built 1985 Load: 67.1 t ADT: 1,910

US 6 EB

Good

Over: WALNUT CREEK/BIKE PATH

1.0 MI. W OF JCT. I-35/80, Polk, IA

Built 1998 Load: 67.1 t ADT: 15,350

US 6 WB

Good

Over: WALNUT CREEK/BIKE PATH

1.0 MI W OF JCT I-35/80, Polk, IA

Built 1998 Load: 67.1 t ADT: 15,350

IA 31

Good

Over: SMOKEY HOLLOW CREEK

0.1 mi. N of Jct. IA 141, Woodbury, IA

Built 2001 Load: 67.1 t ADT: 840

72 ST

Good

Over: BR. OF PRAIRE CREEK

083112501, Benton, IA

Built 2000 Load: 67.4 t ADT: 15

ARLINGTON ST

Good

Over: BR W FORK CEDAR RIVER

093183101, Butler, IA

Built 2000 Load: 67.5 t ADT: 430

FM

Good

Over: MIDDLE WILLOW CREEK

083412704, Crawford, IA

Built 1967 Load: 67.7 t ADT: 358

HILLS RD.

Good

Over: FARM CREEK

086020204, Jones, IA

Built 2008 Load: 67.7 t ADT: 29

LOCAL

Good

Over: COTTONWOOD DRAIN

071010603, Des Moines, IA

Built 2007 Load: 67.8 t ADT: 11

118TH ST.

Good

Over: RAT RUN CREEK

083E10404, Clinton, IA

Built 2010 Load: 68.4 t ADT: 47

BURL LANE

Good

Over: STREAM

081332004, Guthrie, IA

Built 2013 Load: 68.8 t ADT: 26

KIRKWOOD

Good

Over: HUNTER CR

069233103, Wayne, IA

Built 2002 Load: 68.8 t ADT: 20

148TH ST.

Good

Over: CREEK

00000, Clinton, IA

Built 2011 Load: 69.0 t ADT: 62

Showing 16,351-16,400 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.