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

150TH AVENUE

Good

Over: CREEK

083E12504, Clinton, IA

Built 2013 Load: 37.3 t ADT: 35

FM - 180TH AVE

Good

Over: SAND CREEK

088050804, Delaware, IA

Built 1981 Load: 37.3 t ADT: 960

LOCAL

Good

Over: FK OF BEAVER CREEK

089171103, Grundy, IA

Built 1995 Load: 37.3 t ADT: 20

LOCAL

Good

Over: SMALL STREAM

087181002, Grundy, IA

Built 1999 Load: 37.3 t ADT: 78

280TH STREET

Good

Over: ALLEN CREEK

078440501, Harrison, IA

Built 2020 Load: 37.3 t ADT: 45

US 34 EB

Good

Over: UNNAMED CREEK

1.2 mi. W of Jct. IA #1, Jefferson, IA

Built 2006 Load: 37.3 t ADT: 2,485

US 34 WB

Good

Over: UNNAMED CREEK

1.3 mi. W of Jct. IA #1, Jefferson, IA

Built 2006 Load: 37.3 t ADT: 2,485

COUNTY RD. X-75

Good

Over: WAPSIPINICON RIVER

083011806, Jones, IA

Built 1985 Load: 37.3 t ADT: 226

STARLING AVE

Good

Over: DRY RUN

095403302, O'Brien, IA

Built 2018 Load: 37.3 t ADT: 30

QUARRY ROAD

Good

Over: W FORK LITTLE SIOUX

9044263104095, Plymouth, IA

Built 2022 Load: 37.3 t ADT: 26

HONEYSUCKLE RD

Good

Over: SILVER CREEK

075411201, Pottawattamie, IA

Built 2011 Load: 37.3 t ADT: 29

145TH AVE

Good

Over: WAPSIPINICON RIVER

080E30906, Scott, IA

Built 2003 Load: 37.3 t ADT: 60

255TH AVE

Good

Over: CREEK

080E53206, Scott, IA

Built 1999 Load: 37.3 t ADT: 15

I 74 EB ON RAMP

Good

Over: Bike Trail

U.S. 67 RAMP C, Scott, IA

Built 2021 Load: 37.3 t ADT: 8,900

J12 118TH RD

Good

Over: STUMP CREEK

070110830, Van Buren, IA

Built 2019 Load: 37.3 t ADT: 35

LOCAL ROAD

Good

Over: WEST CREEK

074243204, Warren, IA

Built 1993 Load: 37.3 t ADT: 34

IA 175

Good

Over: SKILLET CREEK

1.3 mi E of E jct US 169, Webster, IA

Built 1966 Load: 37.3 t ADT: 1,280

IA 9

Good

Over: BROWN CREEK

1.8 mi E of Jct IA 4, Emmet, IA

Built 1986 Load: 37.4 t ADT: 2,740

THRUSH AVE

Good

Over: BEAVER CREEK

090193202, Franklin, IA

Built 1991 Load: 37.4 t ADT: 30

FM

Good

Over: POSSUM CREEK

069432601, Fremont, IA

Built 1985 Load: 37.4 t ADT: 91

LOCAL ROAD

Good

Over: BRANCH BLACK HAWK CREEK

087181202, Grundy, IA

Built 1990 Load: 37.4 t ADT: 49

LOCAL

Good

Over: STREAM

081311601, Guthrie, IA

Built 2006 Load: 37.4 t ADT: 50

LOCAL

Good

Over: IOWAY CREEK

086262602, Hamilton, IA

Built 1988 Load: 37.4 t ADT: 11

LOCAL

Good

Over: TIPTON CREEK

087210602, Hardin, IA

Built 1989 Load: 37.4 t ADT: 30

POLK AVE

Good

Over: LINGLE CREEK

081060304, Johnson, IA

Built 1986 Load: 37.4 t ADT: 59

FM

Good

Over: STREAM

084440904, Monona, IA

Built 1957 Load: 37.4 t ADT: 11

IA 60 NB

Good

Over: FLOYD RIVER

0.7 mi S of jct IA 10, Sioux, IA

Built 2002 Load: 37.4 t ADT: 2,035

145TH AVE

Good

Over: CREEK

081E12604, Clinton, IA

Built 2001 Load: 37.5 t ADT: 82

335TH AVE

Good

Over: BAIRD CREEK

083E41303, Clinton, IA

Built 1997 Load: 37.5 t ADT: 16

130TH ST

Good

Over: CREEK

083E62301, Clinton, IA

Built 2022 Load: 37.5 t ADT: 25

195TH ST

Good

Over: CREEK

000000000, Clinton, IA

Built 2009 Load: 37.5 t ADT: 26

US 20 RAMPS

Good

Over: DRAINAGE DITCH

JCT US 20 & SR Y17, Dubuque, IA

Built 1988 Load: 37.5 t ADT: 1,010

IA 136

Good

Over: BEAR CREEK

0.4 mi. S of Jct. IA 64, Jones, IA

Built 1983 Load: 37.5 t ADT: 670

IMPERIAL RD

Good

Over: CREEK

090462904, Plymouth, IA

Built 1977 Load: 37.5 t ADT: 379

SB US 65

Good

Over: OVER 4 MI. CK & IAIS RR

2.9 MILES S OF JCT I-80, Polk, IA

Built 1994 Load: 37.5 t ADT: 14,300

IA 210

Good

Over: BRANCH WOLF CREEK

0.6 MILES WEST OF US 65, Story, IA

Built 1993 Load: 37.5 t ADT: 760

R70/580TH AVE

Good

Over: DRAINAGE DITCH

082230402, Story, IA

Built 1989 Load: 37.5 t ADT: 818

580TH AVE

Good

Over: DRAINAGE DITCH

082230402, Story, IA

Built 1989 Load: 37.5 t ADT: 818

120TH AVE

Good

Over: COOPER CREEK

068190902, Appanoose, IA

Built 2013 Load: 37.6 t ADT: 26

461ST ST

Good

Over: CHARITON RIVER

069180105, Appanoose, IA

Built 2003 Load: 37.6 t ADT: 26

J 13 (405TH ST)

Good

Over: SMALL STREAM

070160905, Appanoose, IA

Built 2012 Load: 37.6 t ADT: 25

LOCAL

Good

Over: E NISHNABOTNA RIVER

078350501, Audubon, IA

Built 1996 Load: 37.6 t ADT: 41

KINGBIRD AVE

Good

Over: BR NISHNABOTNA RIVER

1.5 Mile N. of Co Hwy F32, Audubon, IA

Built 2016 Load: 37.6 t ADT: 34

LARK AVE

Good

Over: CREEK

FM 80353606, Audubon, IA

Built 2017 Load: 37.6 t ADT: 60

E24 61ST ST LANE

Good

Over: STREAM

085093303, Benton, IA

Built 2020 Load: 37.6 t ADT: 1,532

GRUNDY RD

Good

Over: TRIB TO BLACK HAWK CREEK

88-14-07-06-10, Black Hawk, IA

Built 1982 Load: 37.6 t ADT: 196

NB US 218

Good

Over: OVER CEDR RR

0.8 MI. N OF Jct. IA. 57, Black Hawk, IA

Built 1995 Load: 37.6 t ADT: 11,850

SB US 218

Good

Over: OVER CEDR RR

0.8 MI. N OF Jct. IA. 57, Black Hawk, IA

Built 1995 Load: 37.6 t ADT: 11,850

MIDWAY AVE

Good

Over: CRANE CREEK

092120702, Bremer, IA

Built 2022 Load: 37.6 t ADT: 49

USHER AVE

Good

Over: STREAM

093110902, Bremer, IA

Built 2004 Load: 37.6 t ADT: 20

Showing 13,451-13,500 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.