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

JAGUAR RD

Good

Over: ELK CREEK

000000000, Clayton, IA

Built 2009 Load: 42.8 t ADT: 579

A17 130TH ST

Good

Over: W FORK DES MOINES RIVER

100342801, Emmet, IA

Built 2019 Load: 42.8 t ADT: 240

EB US 20

Good

Over: SOUTH FORK IOWA RIVER

1.0 MILE E OF JCT SR S27, Hardin, IA

Built 1999 Load: 42.8 t ADT: 4,650

VIRGINIA AVE

Good

Over: CREEK

T93N R27W Vernon TWP, Humboldt, IA

Built 2020 Load: 42.8 t ADT: 40

B40 210TH ST

Good

Over: E FORK DES MOINES RIVER

095291001, Kossuth, IA

Built 2020 Load: 42.8 t ADT: 1,716

T 40 MONUMENT AVE

Good

Over: CREEK

0.05 miles N of 465th, Mitchell, IA

Built 2022 Load: 42.8 t ADT: 786

IA 37

Good

Over: EAST WILLOW RIVER

0.7 mi. E of SR E54, Monona, IA

Built 1996 Load: 42.8 t ADT: 830

FM

Good

Over: FLOYD RIVER

9345240310, Plymouth, IA

Built 2010 Load: 42.8 t ADT: 249

S GRAND AVE

Good

Over: IOWAY CREEK

0.1 Mi S of S 5th Street, Story, IA

Built 2021 Load: 42.8 t ADT: 4,085

M.L.K. JR DR

Good

Over: OVER CC RR

CITY BRIDGE NO. 53, Black Hawk, IA

Built 1996 Load: 42.9 t ADT: 6,494

140TH STREET

Good

Over: CREEK

083E62801, Clinton, IA

Built 1961 Load: 42.9 t ADT: 860

US 151 NB

Good

Over: N FORK MAQUOKETA RIVER

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

Built 2002 Load: 42.9 t ADT: 4,550

EDGEWOOD RD

Good

Over: PRAIRIE CREEK & UP RR

082070704, Linn, IA

Built 2009 Load: 42.9 t ADT: 10,700

US 61 SB

Good

Over: PINE CREEK

6.3 mi. N of Jct. IA 38, Muscatine, IA

Built 1997 Load: 42.9 t ADT: 5,200

350TH ST

Good

Over: WATERMAN CREEK

Waterman Creek @ 350th St, O'Brien, IA

Built 2017 Load: 42.9 t ADT: 72

230TH ST

Good

Over: BIG WHISKEY SLOUGH

9143110110, Plymouth, IA

Built 2017 Load: 42.9 t ADT: 15

EB I-235

Good

Over: UP RR

1.3 MILES E OF JCT US 6, Polk, IA

Built 2006 Load: 42.9 t ADT: 25,550

NB I 35

Good

Over: CLANTON CREEK

2.4 mi. S of Jct. IA #92, Warren, IA

Built 2007 Load: 42.9 t ADT: 11,400

280TH STREET

Good

Over: CREEK

081E13303, Clinton, IA

Built 2004 Load: 43.0 t ADT: 25

LOCAL

Good

Over: BR FISH CREEK

070061606, Henry, IA

Built 1997 Load: 43.0 t ADT: 145

IA 136

Good

Over: OVRFLW S F MAQUOKETA RVR

8.2 MI. S OF JCT. US 151, Jones, IA

Built 1987 Load: 43.0 t ADT: 770

FM

Good

Over: SUGAR CREEK

069062101, Lee, IA

Built 2001 Load: 43.0 t ADT: 400

FM K-42

Good

Over: DRAINAGE

091460202, Plymouth, IA

Built 2008 Load: 43.0 t ADT: 748

CO RD W64

Good

Over: GOOSE CREEK

076062202, Washington, IA

Built 2004 Load: 43.0 t ADT: 520

CO RD W64

Good

Over: DAVIS CREEK

077063402, Washington, IA

Built 2004 Load: 43.0 t ADT: 790

LOCAL

Good

Over: SOUTH FORK LONG CREEK

075062802, Washington, IA

Built 2009 Load: 43.0 t ADT: 161

250TH ST

Good

Over: W FORK NODAWAY RIVER

0.7 mi E of N54 on 250th, Adair, IA

Built 2021 Load: 43.1 t ADT: 123

FM

Good

Over: BEAVER CREEK

090182701, Butler, IA

Built 2008 Load: 43.1 t ADT: 187

LOCAL

Good

Over: WAPSIPINICON RIVER

094131001, Chickasaw, IA

Built 2013 Load: 43.1 t ADT: 35

232ND TRL

Good

Over: S WYACONDAH DITCH

404, Davis, IA

Built 2013 Load: 43.1 t ADT: 60

STOFFEL RD

Good

Over: STREAM

087001E2303, Dubuque, IA

Built 2018 Load: 43.1 t ADT: 118

X AVE

Good

Over: PINE CREEK

087190304, Hardin, IA

Built 2021 Load: 43.1 t ADT: 51

155TH ST

Good

Over: BOYER RIVER

081413107, Harrison, IA

Built 2018 Load: 43.1 t ADT: 40

LOCAL

Good

Over: BIG CREEK

071061805, Henry, IA

Built 2010 Load: 43.1 t ADT: 113

US 151 NB

Good

Over: KITTY CREEK

1.0 mi. S of Jct. SR X44, Jones, IA

Built 2002 Load: 43.1 t ADT: 6,100

25TH PLACE

Good

Over: COAL CREEK

076212904, Marion, IA

Built 2021 Load: 43.1 t ADT: 30

500TH ST

Good

Over: STREAM

094313201, Palo Alto, IA

Built 2016 Load: 43.1 t ADT: 5

350TH ST

Good

Over: STREAM

096331501, Palo Alto, IA

Built 2016 Load: 43.1 t ADT: 26

NW 70TH AVENUE

Good

Over: BEAVER CREEK

000000000, Polk, IA

Built 1994 Load: 43.1 t ADT: 5,205

UNIVSITY RAMP A

Good

Over: UPRR

0.2 MILES E OF JCT IA 163, Polk, IA

Built 2001 Load: 43.1 t ADT: 2,300

VANDALIA RD

Good

Over: DRAINAGE

078231600, Polk, IA

Built 2020 Load: 43.1 t ADT: 6,300

QUAIL AVE

Good

Over: QUARRY HAUL RD

088280512, Webster, IA

Built 2010 Load: 43.1 t ADT: 7,579

NB I-35

Good

Over: DRAINAGE DITCH #29

1.3 mi N of jct SR C70, Wright, IA

Built 1974 Load: 43.1 t ADT: 8,250

FM

Good

Over: LONG DICK CREEK

086233504, Hamilton, IA

Built 1997 Load: 43.2 t ADT: 559

LOCAL

Good

Over: MIDDLE RIVER

000000000, Adair, IA

Built 2009 Load: 43.3 t ADT: 41

W35 QUASQUETON AVE

Good

Over: SMALL CREEK

087081502, Buchanan, IA

Built 2019 Load: 43.3 t ADT: 1,159

US 18 WB

Good

Over: CERRO GORDO COUNTY TRAIL

5.0 mi. E of Jct. I-35, Cerro Gordo, IA

Built 1997 Load: 43.3 t ADT: 4,450

US 20 EB

Good

Over: BEAVER CREEK

4.4 MILES E OF JCT. US 65, Hardin, IA

Built 2003 Load: 43.3 t ADT: 4,850

US 20 WB

Good

Over: BEAVER CREEK

4.4 MILES EAST JCT US 65, Hardin, IA

Built 2003 Load: 43.3 t ADT: 4,850

LOCAL

Good

Over: PRAIRIE CREEK

093271404, Humboldt, IA

Built 2008 Load: 43.3 t ADT: 50

Showing 14,851-14,900 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.