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

096462002, Sioux, IA

Built 1995 Load: 50.0 t ADT: 90

FM

Good

Over: DRY CREEK

096462101, Sioux, IA

Built 2004 Load: 50.0 t ADT: 857

LOCAL

Good

Over: SMALL STREAM

097471501, Sioux, IA

Built 1988 Load: 50.0 t ADT: 40

560TH AVE

Good

Over: SMALL STREAM

082231804, Story, IA

Built 1994 Load: 50.0 t ADT: 259

LOCAL

Good

Over: BRANCH IOWA RIVER

084162402, Tama, IA

Built 2002 Load: 50.0 t ADT: 59

N 99TH AVE E

Good

Over: ROCK CREEK

081171801, Jasper, IA

Built 2012 Load: 50.1 t ADT: 5

RACCOON

Good

Over: NINE MILE CREEK

070233501, Wayne, IA

Built 2016 Load: 50.1 t ADT: 15

H20 125TH ST

Good

Over: MIDDLE NODAWAY RIVER

073341409, Adams, IA

Built 2015 Load: 50.2 t ADT: 170

US 65

Good

Over: MINERVA CREEK

0.7 MILES S OF JCT SR D65, Hardin, IA

Built 1985 Load: 50.2 t ADT: 1,330

584TH AVE

Good

Over: SMALL CREEK

084E63602, Jackson, IA

Built 2018 Load: 50.2 t ADT: 29

T 12

Good

Over: N SKUNK RIVER

080180604, Jasper, IA

Built 2017 Load: 50.2 t ADT: 1,030

E34(CO HOME RD)

Good

Over: BERRYS RUN

East of N Marion Rd, Linn, IA

Built 2013 Load: 50.2 t ADT: 6,874

260TH ST

Good

Over: CREEK

091462901, Plymouth, IA

Built 2002 Load: 50.2 t ADT: 26

32ND ST SE

Good

Over: MUD CREEK

079220700, Polk, IA

Built 2005 Load: 50.2 t ADT: 530

I 29

Good

Over: DRAINAGE DITCH

2.4 miles south I-880, Pottawattamie, IA

Built 2022 Load: 50.2 t ADT: 20,600

LOCAL

Good

Over: STREAM

068220503, Wayne, IA

Built 2000 Load: 50.2 t ADT: 11

S34 140TH ST

Good

Over: STREAM

069213202, Wayne, IA

Built 2017 Load: 50.2 t ADT: 130

290TH ST

Good

Over: WOLF CREEK

086451103, Woodbury, IA

Built 2013 Load: 50.2 t ADT: 30

240TH ST

Good

Over: STREAM

087421401, Woodbury, IA

Built 2020 Load: 50.2 t ADT: 20

367TH AVE

Good

Over: SMALL STREAM

082E53306, Clinton, IA

Built 1998 Load: 50.3 t ADT: 25

LOCAL ROAD

Good

Over: TARKIO CREEK

073372201, Montgomery, IA

Built 1996 Load: 50.3 t ADT: 34

NB IA 27 RAMP

Good

Over: DRY RUN CREEK BIKE PATH

1.3 MI.S.OF JCT.US 218, Black Hawk, IA

Built 1992 Load: 50.4 t ADT: 3,360

140TH STREET

Good

Over: CREEK

083E22601, Clinton, IA

Built 1988 Load: 50.4 t ADT: 47

FM

Good

Over: CHARITON RIVER

072213004, Lucas, IA

Built 1998 Load: 50.4 t ADT: 230

SB US 65

Good

Over: DES MONES RIVER

2.6 MI. S OF JCT. IA 163, Polk, IA

Built 1997 Load: 50.4 t ADT: 12,300

110TH ST

Good

Over: NORTH RIVER

3.4 mi E of IA25 on 110th, Adair, IA

Built 2021 Load: 50.5 t ADT: 26

ORANGE AVE

Good

Over: STREAM

77312105, Adair, IA

Built 2014 Load: 50.5 t ADT: 15

180TH ST

Good

Over: ROCK CREEK

069091601, Van Buren, IA

Built 2019 Load: 50.5 t ADT: 91

FM

Good

Over: BRANCH NORTH TURKEY CRK

076310901, Adair, IA

Built 2002 Load: 50.7 t ADT: 79

IA 187

Good

Over: PRAIRIE CREEK

1.6 MI. N OF US #20, Buchanan, IA

Built 1989 Load: 50.7 t ADT: 1,960

262ND AVE

Good

Over: CREEK

081E33504, Clinton, IA

Built 2017 Load: 50.9 t ADT: 62

R30 150TH AVE

Good

Over: EAST FORK BIG CREEK

068273602, Decatur, IA

Built 2017 Load: 50.9 t ADT: 210

RAMP BR D-4

Good

Over: CITY ST ROW

0.3 mi. N of Jct 922, Linn, IA

Built 1979 Load: 50.9 t ADT: 7,500

FM

Good

Over: THREE MILE CREEK

073301306, Union, IA

Built 2010 Load: 50.9 t ADT: 350

IA 83

Good

Over: DRAINAGE DITCH

0.6 MI. E OF S.R. N28, Cass, IA

Built 1987 Load: 51.0 t ADT: 2,120

150TH ST.

Good

Over: STREAM

083E13509, Clinton, IA

Built 1991 Load: 51.0 t ADT: 80

LOCAL

Good

Over: STREAM

070273102, Decatur, IA

Built 1996 Load: 51.0 t ADT: 5

LCL-DEACON RD

Good

Over: PONY CREEK

072430918, Mills, IA

Built 1992 Load: 51.0 t ADT: 278

FM

Good

Over: NODAWAY RIVER

076330401, Adair, IA

Built 2002 Load: 51.1 t ADT: 139

65TH ST

Good

Over: MUD CREEK

084112201, Benton, IA

Built 2000 Load: 51.1 t ADT: 45

VERMONT AVE

Good

Over: ROCK CR

081013402, Cedar, IA

Built 2000 Load: 51.1 t ADT: 20

US 59

Good

Over: GREY CREEK

2.0 mi N of Jct. IA 3, Cherokee, IA

Built 1985 Load: 51.1 t ADT: 2,000

I 380

Good

Over: DRAINAGE DITCH

0.5 mi. S of Jct. IA 150, Benton, IA

Built 1982 Load: 51.2 t ADT: 21,300

INDIAN CREEK RD

Good

Over: TRIB TO SPRING CREEK

88-11-15-01-10, Black Hawk, IA

Built 1994 Load: 51.2 t ADT: 49

160TH ST

Good

Over: DD NO 11

082E10201, Clinton, IA

Built 2022 Load: 51.2 t ADT: 51

190TH STREET

Good

Over: CREEK

082E32401, Clinton, IA

Built 1961 Load: 51.2 t ADT: 710

FM

Good

Over: SOUTH RACCOON RIVER

078290210, Dallas, IA

Built 1981 Load: 51.2 t ADT: 170

MITCHELL MILL RD

Good

Over: SMALL STREAM

088E33204, Dubuque, IA

Built 2017 Load: 51.2 t ADT: 34

LOVERS LANE

Good

Over: CREEK

090E20903, Dubuque, IA

Built 2019 Load: 51.2 t ADT: 45

INDIGO AVE

Good

Over: DRAINAGE DITCH #3

091210902, Franklin, IA

Built 2012 Load: 51.2 t ADT: 21

Showing 15,851-15,900 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.