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

155TH ST

Good

Over: SILVER CREEK

083E73105, Clinton, IA

Built 2012 Load: 43.7 t ADT: 91

LOCAL

Good

Over: SOUTH WILLOW CREEK

082411802, Crawford, IA

Built 2004 Load: 43.7 t ADT: 26

LOCAL

Good

Over: BEAVER CREEK

080261304, Dallas, IA

Built 1982 Load: 43.7 t ADT: 154

FM

Good

Over: FOX RIVER

069142404, Davis, IA

Built 2008 Load: 43.7 t ADT: 290

220TH AVE

Good

Over: BUCK CREEK

087040702, Delaware, IA

Built 2017 Load: 43.7 t ADT: 49

110TH AVE

Good

Over: STONY CREEK

098380802, Dickinson, IA

Built 2022 Load: 43.7 t ADT: 35

FISCHER RD

Good

Over: PRAIRIE CREEK

087E12504, Dubuque, IA

Built 2018 Load: 43.7 t ADT: 29

M25 MARKET AVE

Good

Over: ELK CREEK

087390502, Ida, IA

Built 2012 Load: 43.7 t ADT: 589

150TH ST

Good

Over: BRUSH CREEK

COUNTY, Jackson, IA

Built 2011 Load: 43.7 t ADT: 550

F48

Good

Over: CHERRY CREEK

080193221, Jasper, IA

Built 2019 Load: 43.7 t ADT: 2,580

ROHRET RD

Good

Over: BRANCH OLD MANS CREEK

079083001, Johnson, IA

Built 2022 Load: 43.7 t ADT: 90

X 75

Good

Over: BIG BEAR CREEK

084013004, Jones, IA

Built 2017 Load: 43.7 t ADT: 403

S33 235TH TRAIL

Good

Over: BR LITTLE WHITEBREAST CR

073213204, Lucas, IA

Built 2017 Load: 43.7 t ADT: 130

IA 330

Good

Over: IOWA RIVER

1.0 MI N OF N JCT SR E29, Marshall, IA

Built 2001 Load: 43.7 t ADT: 2,790

NEW HIGHLAND AC

Good

Over: LYNN CREEK

083180900, Marshall, IA

Built 2008 Load: 43.7 t ADT: 1,738

IA 9

Good

Over: CEDAR RIVER

2.0 mi. W of W Jct.US 218, Mitchell, IA

Built 1992 Load: 43.7 t ADT: 2,990

LOCAL

Good

Over: SOLDIER RIVER

083420403, Monona, IA

Built 2009 Load: 43.7 t ADT: 11

E26 160TH ST

Good

Over: RUSH CREEK

084420203, Monona, IA

Built 2021 Load: 43.7 t ADT: 79

FM

Good

Over: WATERMAN CR

094391401, O'Brien, IA

Built 2005 Load: 43.7 t ADT: 45

NATURE AVE

Good

Over: DEEP CREEK

9345360210, Plymouth, IA

Built 2018 Load: 43.7 t ADT: 30

130TH ST

Good

Over: PLUM CREEK

070301901, Ringgold, IA

Built 2011 Load: 43.7 t ADT: 45

320TH ST

Good

Over: CREEK

081E13301, Scott, IA

Built 2013 Load: 43.7 t ADT: 45

1400TH ST

Good

Over: W NISHNABOTNA RIVER

1400th St W of Orange Rd, Shelby, IA

Built 2015 Load: 43.7 t ADT: 82

IA 137

Good

Over: DES MOINES RIVER

0.1 mi. N of Jct. SR T-61, Wapello, IA

Built 2006 Load: 43.7 t ADT: 5,800

QUINCY AVE

Good

Over: BEAR CREEK

072142312, Wapello, IA

Built 2012 Load: 43.7 t ADT: 3,610

BIRCH RD

Good

Over: LOCUST CREEK

067202201, Wayne, IA

Built 2023 Load: 43.7 t ADT: 70

FM

Good

Over: WOLF CREEK

087443003, Woodbury, IA

Built 2009 Load: 43.7 t ADT: 330

K67 HANCOCK AVE

Good

Over: WOLF CREEK

088452404, Woodbury, IA

Built 2019 Load: 43.7 t ADT: 40

LOCAL

Good

Over: BEAVER CREEK

095182902, Floyd, IA

Built 2001 Load: 43.8 t ADT: 70

WILSON AVE

Good

Over: WATERMAN CREEK

94390304, O'Brien, IA

Built 2020 Load: 43.9 t ADT: 21

IA 415

Good

Over: ROCK CREEK

1.9 MILES N OF JCT IA 160, Polk, IA

Built 1993 Load: 43.9 t ADT: 9,100

HAWTHORNE AVE

Good

Over: FIELD STREAM

083352904, Carroll, IA

Built 2011 Load: 44.1 t ADT: 60

LOCAL 297 ST

Good

Over: SMALL STREAM

087041703, Delaware, IA

Built 1993 Load: 44.1 t ADT: 20

D22 165TH ST

Good

Over: UNNAMED CREEK

088410607, Ida, IA

Built 2022 Load: 44.1 t ADT: 319

F36 PUTNAM RD

Good

Over: RAPID CREEK

080050908, Johnson, IA

Built 2021 Load: 44.1 t ADT: 180

IA 1

Good

Over: CEDAR RIVER

3.1 MI. S OF JCT. US 30, Linn, IA

Built 1992 Load: 44.1 t ADT: 5,600

FRANKLIN ST

Good

Over: BRANCH BLUE CREEK

000000000, Linn, IA

Built 2019 Load: 44.1 t ADT: 5,513

SUTTON RD

Good

Over: TRIB TO WALNUT CREEK

300 N, 200' E of 18-86-6, Linn, IA

Built 2015 Load: 44.1 t ADT: 79

LAMBERT AVE

Good

Over: PONY CREEK

0.5 MI. W OF W JCT I-29, Mills, IA

Built 1931 Load: 44.1 t ADT: 468

FM C-70

Good

Over: DRAINAGE DITCH

090453101, Plymouth, IA

Built 1995 Load: 44.1 t ADT: 559

WB I-235

Good

Over: UP RR

1.3 MILES E OF JCT US 6, Polk, IA

Built 2006 Load: 44.1 t ADT: 25,550

L 34

Good

Over: POTATO CREEK

077432402, Pottawattamie, IA

Built 2013 Load: 44.1 t ADT: 528

P AVE

Good

Over: BUTTERICK CREEK

085301002, Greene, IA

Built 1986 Load: 44.2 t ADT: 11

FOREST ST S

Good

Over: S SKUNK RIVER

079210404, Jasper, IA

Built 2004 Load: 44.2 t ADT: 200

S 112TH AVE EAST

Good

Over: BUCKLEY CREEK

078173001, Jasper, IA

Built 2021 Load: 44.2 t ADT: 45

US 20 EB

Good

Over: LOCAL STREAM

0.1 MILE WEST JCT. SR T55, Grundy, IA

Built 1999 Load: 44.3 t ADT: 6,500

IA 4

Good

Over: MOSQUITO CREEK

0.3 mi. S of S Jct IA 141, Guthrie, IA

Built 2001 Load: 44.3 t ADT: 1,260

US 61 SB

Good

Over: FARMERS CREEK

0.1 mi. N of Jct. SR E17, Jackson, IA

Built 1998 Load: 44.3 t ADT: 4,050

LOCAL

Good

Over: SMITH CREEK

073113507, Jefferson, IA

Built 1970 Load: 44.3 t ADT: 40

NB I-29

Good

Over: PIGEON CREEK

1.4 mi. S of S Jct. I-680, Pottawattamie, IA

Built 2004 Load: 44.3 t ADT: 8,250

Showing 14,951-15,000 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.