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

R30 130TH ST

Good

Over: BEAVER CREEK

081271001, Dallas, IA

Built 2017 Load: 32.4 t ADT: 329

AURORA AVE

Good

Over: WALNUT CREEK

AURORA AVE, Dallas, IA

Built 2012 Load: 32.4 t ADT: 356

MEREDITH DR WB

Good

Over: WALNUT CREEK

MEREDITH DR WB, Dallas, IA

Built 2013 Load: 32.4 t ADT: 1,107

MEREDITH DR EB

Good

Over: WALNUT CREEK

MEREDITH DR EB, Dallas, IA

Built 2013 Load: 32.4 t ADT: 1,168

156TH ST NB

Good

Over: WALNUT CREEK

200 ft North of Brookview, Dallas, IA

Built 2015 Load: 32.4 t ADT: 222

WESTGATE PARKWAY

Good

Over: LITTLE WALNUT CREEK

079262200, Dallas, IA

Built 2020 Load: 32.4 t ADT: 289

WINDCREST DRIVE

Good

Over: OXLEY CREEK

080260100, Dallas, IA

Built 2021 Load: 32.4 t ADT: 6

GRAND AVE

Good

Over: SUGAR CREEK

EB Grand Ave o SugarCreek, Dallas, IA

Built 2023 Load: 32.4 t

MULBERRY AVE

Good

Over: SMALL STREAM

067130802, Davis, IA

Built 2017 Load: 32.4 t ADT: 20

ROBIN BVLD

Good

Over: S WYACONDAH DITCH

067131205, Davis, IA

Built 2018 Load: 32.4 t ADT: 50

MAHOGANY AVE

Good

Over: TRIB S WYACONDAH DITCH

068131902, Davis, IA

Built 2021 Load: 32.4 t ADT: 26

KEY BLVD

Good

Over: S WYACONDAH DITCH

68140204, Davis, IA

Built 2016 Load: 32.4 t ADT: 70

JEWEL AVE

Good

Over: S WYACONDAH DITCH

068140304, Davis, IA

Built 2020 Load: 32.4 t ADT: 30

JADE AVE

Good

Over: CARTER CREEK

068142702, Davis, IA

Built 2021 Load: 32.4 t ADT: 25

EBONY AVE

Good

Over: FABIUS CREEK

68153506, Davis, IA

Built 2016 Load: 32.4 t ADT: 45

192ND ST

Good

Over: FOX RIVER

069141803, Davis, IA

Built 2019 Load: 32.4 t ADT: 25

DRIFTWOOD BLVD

Good

Over: CREEK

069151506, Davis, IA

Built 2014 Load: 32.4 t ADT: 70

208TH ST

Good

Over: FOX RIVER

069152009, Davis, IA

Built 2019 Load: 32.4 t ADT: 30

CEDAR AVE

Good

Over: CENTER BRANCH FOX RIVER

069152102, Davis, IA

Built 2022 Load: 32.4 t ADT: 11

ECHO AVE

Good

Over: FOX RIVER

069152306, Davis, IA

Built 2014 Load: 32.4 t ADT: 50

CEDAR AVE

Good

Over: TRIB FOX RIVER

069152804, Davis, IA

Built 2021 Load: 32.4 t ADT: 15

APPLE AVE

Good

Over: TRIB S WYACONDAH DITCH

069153004, Davis, IA

Built 2017 Load: 32.4 t ADT: 20

PLEASANTON RD

Good

Over: MCGRUDER CREEK

068250406, Decatur, IA

Built 2015 Load: 32.4 t ADT: 329

R15 125TH AVE

Good

Over: GRAND RIVER

070271604, Decatur, IA

Built 2018 Load: 32.4 t ADT: 219

R15 125TH AVE

Good

Over: SAND CREEK

070272110, Decatur, IA

Built 2019 Load: 32.4 t ADT: 219

LOC 225 ST

Good

Over: SMALL STREAM

088040306, Delaware, IA

Built 1984 Load: 32.4 t ADT: 39

240TH ST

Good

Over: MAQUOKETA RIVER

00000, Delaware, IA

Built 2011 Load: 32.4 t ADT: 1,080

FM 140TH AVE

Good

Over: SAND CREEK

1.1 Mi. North of CR D34, Delaware, IA

Built 2011 Load: 32.4 t ADT: 49

310TH AVE

Good

Over: STREAM

89 03 10 0065, Delaware, IA

Built 2013 Load: 32.4 t ADT: 49

265TH AVE

Good

Over: PLUM CREEK

1 mile North of 195th St., Delaware, IA

Built 2012 Load: 32.4 t ADT: 15

218TH ST

Good

Over: PLUM CREEK

218th St. SE of Earlville, Delaware, IA

Built 2012 Load: 32.4 t ADT: 118

190TH AVE

Good

Over: HONEY CREEK

89 05 10 04, Delaware, IA

Built 2012 Load: 32.4 t ADT: 39

200TH ST

Good

Over: SMALL STREAM

89 04 30 01, Delaware, IA

Built 2013 Load: 32.4 t ADT: 11

US 61 NB

Good

Over: FLINT CREEK

0.6 M N of Memorial Pk RD, Des Moines, IA

Built 2023 Load: 32.4 t

FM

Good

Over: RUNNING SLOUGH DRAIN

071010401, Des Moines, IA

Built 2010 Load: 32.4 t ADT: 260

H40 SPERRY RD

Good

Over: YELLOW SPRING CREEK

071020803, Des Moines, IA

Built 2019 Load: 32.4 t ADT: 227

155TH ST

Good

Over: YELLOW SPRING CREEK

071023507, Des Moines, IA

Built 2014 Load: 32.4 t ADT: 90

US 61 SB

Good

Over: FLINT CREEK

0.3 mi Sof Flint River Rd, Des Moines, IA

Built 2020 Load: 32.4 t ADT: 3,100

190TH AVE

Good

Over: LITTLE SIOUX RIVER

098371502, Dickinson, IA

Built 2022 Load: 32.4 t ADT: 250

FM

Good

Over: CATFISH CREEK

088E22005, Dubuque, IA

Built 2017 Load: 32.4 t ADT: 737

DERBY GRANGE RD

Good

Over: CLOIE BRANCH

089E20805, Dubuque, IA

Built 2011 Load: 32.4 t ADT: 638

N CASCADE RD

Good

Over: SOUTH FORK CATFISH CREEK

88N02ES33NW, Dubuque, IA

Built 2012 Load: 32.4 t ADT: 2,259

SOUTH MOUND RD

Good

Over: NO FORK MAQUOKETA RIVER

9001 28 2010, Dubuque, IA

Built 2016 Load: 32.4 t ADT: 250

BRUNSKILL RD

Good

Over: NORTH CATFISH CREEK

W. OF SOUTH GATE DR., Dubuque, IA

Built 2013 Load: 32.4 t ADT: 865

E 16TH ST

Good

Over: BEE BRANCH

W OF SYCAMORE ST, Dubuque, IA

Built 2011 Load: 32.4 t ADT: 4,265

US 20 EB ON RAMP

Good

Over: S FORK CATFISH CREEK

US 20 & IA 52 SW ARTERIAL, Dubuque, IA

Built 2019 Load: 32.4 t ADT: 2,420

US 20 ON RAMP

Good

Over: S FORK CATFISH CREEK

US 20 & IA 52 SW ARTERIAL, Dubuque, IA

Built 2018 Load: 32.4 t ADT: 1,570

US 52 NB

Good

Over: CATFISH CREEK

US 52 NB OVER CATFISH CRK, Dubuque, IA

Built 2019 Load: 32.4 t ADT: 3,150

AIRBORNE ROAD

Good

Over: S FORK CATFISH CREEK

0.2 MI. S. OF SEIPPEL RD., Dubuque, IA

Built 2019 Load: 32.4 t ADT: 110

US 52 SB

Good

Over: CATFISH CREEK

US 52 SB OVER CATFISH CRK, Dubuque, IA

Built 2019 Load: 32.4 t ADT: 3,150

Showing 10,551-10,600 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.