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

FM

Good

Over: CREEK

089193501, Hardin, IA

Built 1991 Load: 34.6 t ADT: 69

US 20

Good

Over: IOWA RIVER

1.5 mi. W of Jct. SR S56, Hardin, IA

Built 2003 Load: 34.6 t ADT: 9,200

180TH STREET

Good

Over: BOYER RIVER

080421203, Harrison, IA

Built 2002 Load: 34.6 t ADT: 79

QUINCY TRAIL

Good

Over: BOYER RIVER

080422805, Harrison, IA

Built 1994 Load: 34.6 t ADT: 15

FM

Good

Over: E.FK DES MOINES RIVER

092281003, Humboldt, IA

Built 1994 Load: 34.6 t ADT: 190

WB IA 163

Good

Over: WALNUT CREEK

2.4 Mi. W of Jct. IA 117, Jasper, IA

Built 1993 Load: 34.6 t ADT: 5,800

OAKCRESTHILL RD

Good

Over: OLD MAN CREEK

078062114, Johnson, IA

Built 2005 Load: 34.6 t ADT: 1,530

SW NAPLES AVE

Good

Over: OLD MAN'SCREEK

078060508, Johnson, IA

Built 1985 Load: 34.6 t ADT: 150

CO RD W15

Good

Over: SKUNK RIVER

074100204, Keokuk, IA

Built 2004 Load: 34.6 t ADT: 620

I 380 NB

Good

Over: WEST BLUE CREEK

2.7 mi. N of S.R. W36, Linn, IA

Built 1982 Load: 34.6 t ADT: 10,750

LOCAL

Good

Over: WHITEBREAST CREEK

073220201, Lucas, IA

Built 2003 Load: 34.6 t ADT: 60

WB US 30

Good

Over: TIMBER CREEK

3.0 MILES E OF JCT IA 14, Marshall, IA

Built 1995 Load: 34.6 t ADT: 7,300

FM

Good

Over: CEDAR CREEK

073182703, Monroe, IA

Built 2002 Load: 34.6 t ADT: 60

FM

Good

Over: POLLY CREEK

099421301, Osceola, IA

Built 1978 Load: 34.6 t ADT: 968

300TH STREET

Good

Over: TARKIO RIVER

067382001, Page, IA

Built 2006 Load: 34.6 t ADT: 5

LOCAL

Good

Over: DD 81

094312903, Palo Alto, IA

Built 1996 Load: 34.6 t ADT: 72

FM NE 118TH

Good

Over: SKUNK RIVER

080220505, Polk, IA

Built 1992 Load: 34.6 t ADT: 45

NB I-29

Good

Over: HONEY CREEK

4.7 MI. S OF N JCT. I-680, Pottawattamie, IA

Built 2009 Load: 34.6 t ADT: 10,300

SB I-29

Good

Over: HONEY CREEK

4.7 MI. S OF N JCT. I-680, Pottawattamie, IA

Built 2009 Load: 34.6 t ADT: 10,300

300TH STREET

Good

Over: MIDDLE SILVER CREEK

074411902, Pottawattamie, IA

Built 2003 Load: 34.6 t ADT: 79

TAYLOR-PAGE AVE

Good

Over: E NODAWAY RIVER

069350602, Taylor, IA

Built 2002 Load: 34.6 t ADT: 40

LOCAL

Good

Over: STREAM

068203102, Wayne, IA

Built 2000 Load: 34.6 t ADT: 26

LOCAL

Good

Over: IOWA RIVER

091232402, Wright, IA

Built 1998 Load: 34.6 t ADT: 21

110TH ST

Good

Over: MIDDLE RIVER

3.1 mi E of N54 on 110th, Adair, IA

Built 2015 Load: 34.7 t ADT: 51

G61 310TH ST

Good

Over: UNNAMED CREEK

2.4 mi E of N72 on G61, Adair, IA

Built 2015 Load: 34.7 t ADT: 468

FOX RD

Good

Over: TRIB TO SPRING CREEK

88-11-23-01-10, Black Hawk, IA

Built 2000 Load: 34.7 t ADT: 49

E AIRLINE HWY

Good

Over: TRIB TO ELK RUN CREEK

89-12-11-01-10, Black Hawk, IA

Built 2000 Load: 34.7 t ADT: 15

W 27TH ST

Good

Over: TRIB TO BEAVER CREEK

89-14-19-01-10, Black Hawk, IA

Built 1994 Load: 34.7 t ADT: 854

VIKING RD

Good

Over: STREAM

000000000, Black Hawk, IA

Built 1990 Load: 34.7 t ADT: 7,193

GRAND AVE

Good

Over: STREAM

091131804, Bremer, IA

Built 2022 Load: 34.7 t ADT: 216

V65

Good

Over: SMALL STREAM

088100608, Buchanan, IA

Built 2014 Load: 34.7 t ADT: 2,917

T16 DOUGLAS AVE

Good

Over: SMALL STREAM

091181502, Butler, IA

Built 2017 Load: 34.7 t ADT: 579

G43 NEWPORT RD

Good

Over: WEST NODAWAY CREEK

075341201, Cass, IA

Built 2019 Load: 34.7 t ADT: 29

FM M21

Good

Over: SMALL STREAM

091391504, Cherokee, IA

Built 1974 Load: 34.7 t ADT: 390

LOCAL 560TH ST.

Good

Over: SMALL CREEK

091411301, Cherokee, IA

Built 2001 Load: 34.7 t ADT: 26

LOCAL-480TH ST.

Good

Over: CREEK

092410201, Cherokee, IA

Built 1999 Load: 34.7 t ADT: 34

L51 140TH ST

Good

Over: WILLOW CREEK

0.35 Mi S NW Cor 11-83-41, Crawford, IA

Built 2015 Load: 34.7 t ADT: 358

E46 O AVE

Good

Over: WILLOW CREEK

083411602, Crawford, IA

Built 2017 Load: 34.7 t ADT: 40

PRAIRIE CREEK RD

Good

Over: CREEK

087E10303, Dubuque, IA

Built 2018 Load: 34.7 t ADT: 59

REA RD

Good

Over: CREEK

087E11602, Dubuque, IA

Built 2017 Load: 34.7 t ADT: 25

WUCHTER RD

Good

Over: CREEK

088020406, Dubuque, IA

Built 2013 Load: 34.7 t ADT: 70

US 218

Good

Over: STREAM

5.1 miles S of Jct. IA 14, Floyd, IA

Built 1998 Load: 34.7 t ADT: 10,000

LOCAL

Good

Over: BR HAMMERS CREEK

089151402, Grundy, IA

Built 2002 Load: 34.7 t ADT: 29

US 20 WB

Good

Over: STREAM

0.9 MILES W OF JCT SR T55, Grundy, IA

Built 2000 Load: 34.7 t ADT: 6,800

US 20 WB

Good

Over: S BEAVER CREEK

3.5 MILES W OF JCT SR T19, Grundy, IA

Built 2003 Load: 34.7 t ADT: 4,900

US 20 EB

Good

Over: S BEAVER CREEK

3.5 MILES W OF JCT SR T19, Grundy, IA

Built 2003 Load: 34.7 t ADT: 4,900

203RD ST

Good

Over: LYON CREEK

089252603, Hamilton, IA

Built 2019 Load: 34.7 t ADT: 40

LOCAL

Good

Over: BIG CREEK

072063404, Henry, IA

Built 1985 Load: 34.7 t ADT: 140

KANSAS AVE

Good

Over: CREEK

091292304, Humboldt, IA

Built 2017 Load: 34.7 t ADT: 26

US 20

Good

Over: MAPLE RIVER OVERFLOW

4.0 mi. E of E jct. US 59, Ida, IA

Built 2016 Load: 34.7 t ADT: 5,100

Showing 12,751-12,800 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.