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

LOCAL

Good

Over: SMALL STREAM

091171902, Butler, IA

Built 1994 Load: 36.6 t ADT: 62

LOCAL

Good

Over: BIG MARSH

091172701, Butler, IA

Built 1994 Load: 36.6 t ADT: 41

FM

Good

Over: WEST FORK CEDAR RIVER

092182104, Butler, IA

Built 2003 Load: 36.6 t ADT: 619

FM

Good

Over: TROUBLESOME CREEK

077353007, Cass, IA

Built 2005 Load: 36.6 t ADT: 30

LOCAL

Good

Over: TROUBLESOME CREEK

077353103, Cass, IA

Built 2004 Load: 36.6 t ADT: 15

SB I-35

Good

Over: IMRL RR

0.2 MI. S OF JCT. 18, Cerro Gordo, IA

Built 1970 Load: 36.6 t ADT: 10,800

LOCAL-510TH ST

Good

Over: WILLOW CREEK

092412001, Cherokee, IA

Built 1999 Load: 36.6 t ADT: 30

YOUNG WAY

Good

Over: DRY RUN

095110110, Chickasaw, IA

Built 2000 Load: 36.6 t ADT: 5

LOCAL

Good

Over: EAST WAPSIPINICON RIVER

096130901, Chickasaw, IA

Built 1988 Load: 36.6 t ADT: 30

400TH ST

Good

Over: STREAM

095361101, Clay, IA

Built 2014 Load: 36.6 t ADT: 5

197TH ST

Good

Over: SMALL

082E42407, Clinton, IA

Built 1980 Load: 36.6 t ADT: 26

360TH AVE.

Good

Over: CREEK

082E50902, Clinton, IA

Built 1994 Load: 36.6 t ADT: 51

100TH ST.

Good

Over: N BRANCH OF ELK RIVER

083E60405, Clinton, IA

Built 1996 Load: 36.6 t ADT: 59

FM

Good

Over: S WYACONDAH DITCH

067130205, Davis, IA

Built 2001 Load: 36.6 t ADT: 25

LOCAL

Good

Over: CREEK

095182401, Floyd, IA

Built 1990 Load: 36.6 t ADT: 49

LOCAL

Good

Over: SMALL STREAM

097182001, Floyd, IA

Built 1996 Load: 36.6 t ADT: 44

INDIGO AVE

Good

Over: DRAINAGE DITCH NO 55

93211802, Franklin, IA

Built 2018 Load: 36.6 t ADT: 26

SB I-29

Good

Over: WAUBONSIE DITCH

0.5 mi. S of Jct. SR L31, Fremont, IA

Built 2011 Load: 36.6 t ADT: 6,450

390 AVENUE

Good

Over: WALNUT CREEK

070403402, Fremont, IA

Built 1993 Load: 36.6 t ADT: 21

3220 REED AVE

Good

Over: SILVER CREEK DD 7

097241204, Hancock, IA

Built 2005 Load: 36.6 t ADT: 153

235TH TRAIL

Good

Over: WILLOW CREEK

079431003, Harrison, IA

Built 2006 Load: 36.6 t ADT: 29

US 52

Good

Over: DME RR

2.6 mi. N of jct. IA 62, Jackson, IA

Built 1996 Load: 36.6 t ADT: 3,100

S 12TH AVE E

Good

Over: SUGAR CREEK

079170105, Jasper, IA

Built 2000 Load: 36.6 t ADT: 82

HALFMOON AVE

Good

Over: STREAM

080073204, Johnson, IA

Built 2003 Load: 36.6 t ADT: 410

I 80 WB

Good

Over: IOWA RIVER

3.0 MI. W OF JCT. IA 1, Johnson, IA

Built 1960 Load: 36.6 t ADT: 32,050

F44 HOOVER HWY NE

Good

Over: BR WAPSINONOC CREEK

0507900375, Johnson, IA

Built 2022 Load: 36.6 t ADT: 3,390

TEMPLE HILL RD

Good

Over: S FORK MAQUOKETA RIVER

085010808, Jones, IA

Built 1991 Load: 36.6 t ADT: 25

LOC 320TH ST

Good

Over: BUFFALO CREEK

097281601, Kossuth, IA

Built 1990 Load: 36.6 t ADT: 26

LOCAL

Good

Over: BIG SUGAR CREEK

068061103, Lee, IA

Built 1987 Load: 36.6 t ADT: 26

IA 146

Good

Over: DRAINAGE DITCH

2.5 MILES S OF JCT US 30, Marshall, IA

Built 1979 Load: 36.6 t ADT: 2,160

US 61 & IA 22

Good

Over: MAD CREEK

0.5 MI. S OF JCT. IA 38, Muscatine, IA

Built 1984 Load: 36.6 t ADT: 18,300

LOCAL

Good

Over: FLOYD RIVER

097401902, O'Brien, IA

Built 1987 Load: 36.6 t ADT: 15

OTTER AVE

Good

Over: PLYMOUTH CREEK

9244290210, Plymouth, IA

Built 2016 Load: 36.6 t ADT: 34

NW 100TH STREET

Good

Over: LITTLE BEAVER CREEK

0.1 MI. S. OF NW 82ND AVE, Polk, IA

Built 2017 Load: 36.6 t ADT: 230

I 80 WB OFF RAMP

Good

Over: DRAINAGE

0.2 MILES E OF US 69, Polk, IA

Built 1999 Load: 36.6 t ADT: 4,080

CHESTNUT ROAD

Good

Over: GRAYBILL CREEK

074401301, Pottawattamie, IA

Built 1997 Load: 36.6 t ADT: 45

BEECHNUT ROAD

Good

Over: SILVER CREEK

074412201, Pottawattamie, IA

Built 1997 Load: 36.6 t ADT: 60

320TH STREET

Good

Over: SILVER CREEK

075410902, Pottawattamie, IA

Built 2016 Load: 36.6 t ADT: 20

ELMTREE ROAD

Good

Over: LITTLE SILVER CREEK

075422501, Pottawattamie, IA

Built 2017 Load: 36.6 t ADT: 26

420TH ST

Good

Over: DRAINAGE

00000, Pottawattamie, IA

Built 2011 Load: 36.6 t ADT: 29

M23 (410TH ST)

Good

Over: STREAM

077401202, Pottawattamie, IA

Built 2012 Load: 36.6 t ADT: 79

TEAKWOOD ROAD

Good

Over: SILVER CREEK

077402201, Pottawattamie, IA

Built 1999 Load: 36.6 t ADT: 15

I 29 NB TO I 80 EB

Good

Over: CBEC RR

I-29 TO I-80 EB RAMP D, Pottawattamie, IA

Built 2019 Load: 36.6 t ADT: 2,720

IA 2

Good

Over: DRAINAGE DITCH

1.7 MI. W OF Jct. SR P33, Ringgold, IA

Built 1988 Load: 36.6 t ADT: 1,150

DAYTON AVE

Good

Over: UPRR

A88500545, Story, IA

Built 2002 Load: 36.6 t ADT: 10,233

FM

Good

Over: WEST 102 RIVER

067352701, Taylor, IA

Built 2006 Load: 36.6 t ADT: 34

FM

Good

Over: EAST FORK CROOKED CREEK

074072410, Washington, IA

Built 1990 Load: 36.6 t ADT: 490

LOCAL

Good

Over: SOUTH FORK LONG CREEK

076073202, Washington, IA

Built 1991 Load: 36.6 t ADT: 110

US 218 SB

Good

Over: N. FORK LONG CREEK

1.0 MI. S OF JCT. IA 92, Washington, IA

Built 1997 Load: 36.6 t ADT: 5,400

LOCAL

Good

Over: BASS CREEK

090291006, Webster, IA

Built 1998 Load: 36.6 t ADT: 35

Showing 13,251-13,300 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.