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

B14 330TH ST

Good

Over: E FORK DES MOINES RIVER

097291201, Kossuth, IA

Built 2022 Load: 42.1 t ADT: 419

HAGERMAN RD

Good

Over: W OTTER CREEK

084080103, Linn, IA

Built 1983 Load: 42.1 t ADT: 137

TRI-COUNTY BR

Good

Over: IOWA RIVER

076050601, Louisa, IA

Built 1980 Load: 42.1 t ADT: 80

IA 96

Good

Over: DEVILS RUN CREEK

1.8 MILES EAST OF SR T29, Marshall, IA

Built 2015 Load: 42.1 t ADT: 1,560

J 56 290TH ST

Good

Over: MIDDLE TARKIO CREEK

067391401, Page, IA

Built 2020 Load: 42.1 t ADT: 20

FM

Good

Over: FOUR MILE CREEK

079231701, Polk, IA

Built 1991 Load: 42.1 t ADT: 1,504

COWLES DRIVE

Good

Over: GARAGE ENTRY LANE

0.3 mi. N of Entrance, Polk, IA

Built 2023 Load: 42.1 t

J20 130TH ST

Good

Over: STREAM

070312301, Ringgold, IA

Built 2020 Load: 42.1 t ADT: 50

395TH ST

Good

Over: FLOYD RIVER

095430309, Sioux, IA

Built 2021 Load: 42.1 t ADT: 60

IA 60 SB

Good

Over: FLOYD RIVER

0.7 mi. S of Jct. IA 10, Sioux, IA

Built 2002 Load: 42.1 t ADT: 2,035

E64

Good

Over: BRANCH OF IOWA RIVER

082151003, Tama, IA

Built 2020 Load: 42.1 t ADT: 491

IA 1

Good

Over: DES MOINES RIVER

3.9 mi. N of jct. IA 2, Van Buren, IA

Built 2007 Load: 42.1 t ADT: 2,270

TIMBER AVE

Good

Over: TRIB DES MOINES RIVER

068083204, Van Buren, IA

Built 2014 Load: 42.1 t ADT: 51

QUAIL ROAD

Good

Over: BEAR CREEK

068091106, Van Buren, IA

Built 2018 Load: 42.1 t ADT: 45

FM

Good

Over: DES MOINES RIVER

071131006, Wapello, IA

Built 1985 Load: 42.1 t ADT: 80

LOCAL

Good

Over: BRANCH SQUAW CREEK

074242702, Warren, IA

Built 2008 Load: 42.1 t ADT: 26

US 65

Good

Over: STREAM

0.1 mi S of jct Co Rd J46, Wayne, IA

Built 2016 Load: 42.1 t ADT: 1,240

GRUNDY AVE

Good

Over: BEAVER CREEK

087452804, Woodbury, IA

Built 2015 Load: 42.1 t ADT: 50

210TH ST.

Good

Over: STREAM

082E63201, Clinton, IA

Built 1957 Load: 42.2 t ADT: 70

NB I-35

Good

Over: OVER ABAND RR

2.9 mi. S of C47, Franklin, IA

Built 1974 Load: 42.2 t ADT: 8,250

US 34 WB

Good

Over: BNSF RR

3.4 mi. E of Jct. SR V63, Jefferson, IA

Built 2008 Load: 42.2 t ADT: 7,800

IA 3 & 17

Good

Over: BOONE RIVER

1.2 mi. E of W Jct. IA 17, Wright, IA

Built 1984 Load: 42.2 t ADT: 2,800

LOCAL

Good

Over: BEAVER CREEK

082282706, Boone, IA

Built 1996 Load: 42.3 t ADT: 60

LOWER LEDGES RD

Good

Over: PEASE CREEK

IN LEDGES STATE PARK, Boone, IA

Built 2011 Load: 42.3 t

E-63

Good

Over: DRAINAGE DITCH 11

082E11401, Clinton, IA

Built 2007 Load: 42.3 t ADT: 320

US 34 WB

Good

Over: SKUNK RIVER

3.8 mi. E of Jct. SR W40, Henry, IA

Built 2004 Load: 42.3 t ADT: 3,400

NEWBOLD RD

Good

Over: E BLUE CREEK

T85N, R08W, SECTION 4, Linn, IA

Built 2017 Load: 42.3 t ADT: 49

LOCAL

Good

Over: OVER UP RR

072210302, Lucas, IA

Built 2009 Load: 42.3 t ADT: 26

252ND TRAIL

Good

Over: UP RR

072211003, Lucas, IA

Built 2009 Load: 42.3 t ADT: 16

LOCAL

Good

Over: BRUSH CREEK

072232104, Lucas, IA

Built 2008 Load: 42.3 t ADT: 35

G73 (325TH ST)

Good

Over: BLUFF CREEK

074172703, Mahaska, IA

Built 2012 Load: 42.3 t ADT: 50

300TH ST

Good

Over: BIG WHISKEY CREEK

090451803, Plymouth, IA

Built 2008 Load: 42.3 t ADT: 40

310TH ST

Good

Over: BIG WHISKEY CREEK

090451903, Plymouth, IA

Built 2008 Load: 42.3 t ADT: 20

FAWN AVE

Good

Over: BROKEN KETTLE CREEK

9247170210, Plymouth, IA

Built 2013 Load: 42.3 t ADT: 30

120TH ST

Good

Over: DEEP CREEK

93431550, Plymouth, IA

Built 2014 Load: 42.3 t ADT: 45

C12 110TH ST

Good

Over: WILLOW CREEK

934411011090, Plymouth, IA

Built 2014 Load: 42.3 t ADT: 30

LOCAL

Good

Over: NO LIZARD CK DD #171

091312201, Pocahontas, IA

Built 2009 Load: 42.3 t ADT: 11

NISHNA AVE

Good

Over: SMALL STREAM

079380103, Shelby, IA

Built 2015 Load: 42.3 t ADT: 40

280TH ST

Good

Over: WEST BR INDIAN CREEK

0.4 miles E of S14, Story, IA

Built 2015 Load: 42.3 t ADT: 131

E23 170TH ST

Good

Over: KEIGLEY BRANCH

084230701, Story, IA

Built 2013 Load: 42.3 t ADT: 120

FM

Good

Over: SALT CREEK

084133402, Tama, IA

Built 2003 Load: 42.3 t ADT: 15

LOCAL

Good

Over: PLATTE RIVER

071313103, Union, IA

Built 1994 Load: 42.3 t ADT: 21

FM

Good

Over: WOLF CREEK

073123303, Wapello, IA

Built 2007 Load: 42.3 t ADT: 20

PINEWOOD AVE

Good

Over: NORTH TURKEY CREEK

1.2 mi N of G27, Adair, IA

Built 2015 Load: 42.4 t ADT: 21

SMITHFIELD DRIVE

Good

Over: BRANCH YELLOW RIVER

096050905, Allamakee, IA

Built 2021 Load: 42.4 t ADT: 59

HICKS RD

Good

Over: GIVEN CREEK

87-14-32-02-10, Black Hawk, IA

Built 1999 Load: 42.4 t ADT: 15

US 20

Good

Over: DRAINAGE DITCH

4.6 mi. W of W jct. IA150, Buchanan, IA

Built 1980 Load: 42.4 t ADT: 10,100

235TH STREET

Good

Over: OVERFLOW OF WAPSIPINICON

081E11003, Clinton, IA

Built 2008 Load: 42.4 t ADT: 510

190TH STREET

Good

Over: SMALL STREAM

082E22301, Clinton, IA

Built 1992 Load: 42.4 t ADT: 490

LOCAL 260 AVE

Good

Over: SMALL STREAM

087041006, Delaware, IA

Built 2001 Load: 42.4 t ADT: 59

Showing 14,751-14,800 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.