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

C33 180TH ST

Good

Over: SMALL STREAM

092161401, Butler, IA

Built 2015 Load: 34.3 t ADT: 805

180 ST

Good

Over: ALRY RUN CREEK

092171301, Butler, IA

Built 2000 Load: 34.3 t ADT: 285

LOCAL

Good

Over: SMALL CREEK

000000000, Carroll, IA

Built 2011 Load: 34.3 t ADT: 50

310TH ST

Good

Over: BR BIG ELKHORN CR

079012301, Cedar, IA

Built 2019 Load: 34.3 t ADT: 80

Y14 HOOVER HWY

Good

Over: YANKEE RUN CREEK

081010309, Cedar, IA

Built 2015 Load: 34.3 t ADT: 560

F16 18TH ST

Good

Over: BALDWIN CREEK

081041503, Cedar, IA

Built 2022 Load: 34.3 t ADT: 50

S56 THRUSH AVE

Good

Over: BEAVER CREEK

0.2 MI N B47, Cerro Gordo, IA

Built 2018 Load: 34.3 t ADT: 697

LOCAL-510TH ST.

Good

Over: DRAINAGE DITCH

092422201, Cherokee, IA

Built 2001 Load: 34.3 t ADT: 40

300TH AVE

Good

Over: CREEK

081E40901, Clinton, IA

Built 2020 Load: 34.3 t ADT: 51

A AVE

Good

Over: BRANCH MOSQUITO CREEK

079290602, Dallas, IA

Built 2015 Load: 34.3 t ADT: 15

267TH ST

Good

Over: TURTLE CREEK

On 267th 1.25 W of X21, Delaware, IA

Built 2014 Load: 34.3 t ADT: 226

FM 150 ST

Good

Over: SMALL STREAM

090063601, Delaware, IA

Built 1986 Load: 34.3 t ADT: 589

WB US 20

Good

Over: OVER CC RR

0.9 MI. E OF JCT. 13, Delaware, IA

Built 1971 Load: 34.3 t ADT: 3,850

HARTBECKE RD

Good

Over: CURRAN-WHITEWATER CREEK

088012106, Dubuque, IA

Built 2012 Load: 34.3 t ADT: 49

OUTER RD

Good

Over: UNNAMED CREEK

091091004, Fayette, IA

Built 2017 Load: 34.3 t ADT: 20

HICKORY AVE

Good

Over: MASON CREEK

079322902, Guthrie, IA

Built 2017 Load: 34.3 t ADT: 20

S 112TH AVE E

Good

Over: LITTLE ELK CREEK

078182601, Jasper, IA

Built 2022 Load: 34.3 t ADT: 20

S 28TH AVE W

Good

Over: SEVERS CREEK

079200901, Jasper, IA

Built 2022 Load: 34.3 t ADT: 51

S60 S 36TH AVE W

Good

Over: SMALL STREAM

079201203, Jasper, IA

Built 2022 Load: 34.3 t ADT: 90

JEWEL STREET

Good

Over: SMALL STREAM

080171002, Jasper, IA

Built 2023 Load: 34.3 t ADT: 60

N 107TH AVE E

Good

Over: POTATO CREEK

081180801, Jasper, IA

Built 2021 Load: 34.3 t ADT: 20

N 115TH AVE E

Good

Over: LITTLE SNIPE CREEK

081190101, Jasper, IA

Built 2022 Load: 34.3 t ADT: 35

N 115TH AVE W

Good

Over: SMALL STREAM

081190401, Jasper, IA

Built 2022 Load: 34.3 t ADT: 51

NORTH 83RD AVE E

Good

Over: SMALL STREAM

081192501, Jasper, IA

Built 2022 Load: 34.3 t ADT: 26

W 84TH ST N

Good

Over: TURKEY CREEK

081203302, Jasper, IA

Built 2022 Load: 34.3 t ADT: 11

RAILROAD ST

Good

Over: SMALL STREAM

080210300, Jasper, IA

Built 2016 Load: 34.3 t ADT: 112

OAKCRESTHILL RD

Good

Over: DRAINAGE DITCH

T78N, R6W, 28, Johnson, IA

Built 2018 Load: 34.3 t ADT: 1,530

MCCOLLISTER BLV

Good

Over: IOWA RIVER

079062201, Johnson, IA

Built 2009 Load: 34.3 t ADT: 6,000

E26 BURNETT STA RD

Good

Over: INDAIN CREEK

085062901, Linn, IA

Built 2021 Load: 34.3 t ADT: 520

M16 370TH ST

Good

Over: NISHNABOTNA RIVER

073402904, Mills, IA

Built 2018 Load: 34.3 t ADT: 210

120TH ST

Good

Over: CREEK

078041601, Muscatine, IA

Built 2020 Load: 34.3 t ADT: 91

F70 155TH ST

Good

Over: SMALL CREEK

078043501, Muscatine, IA

Built 2019 Load: 34.3 t ADT: 110

ORIOLE AVE

Good

Over: JOHNSON CREEK

095410702, O'Brien, IA

Built 2015 Load: 34.3 t ADT: 210

C38

Good

Over: PERRY CREEK

9247360110, Plymouth, IA

Built 2017 Load: 34.3 t ADT: 948

NE 102ND AVE

Good

Over: DRAINAGE DITCH NO 38

080221401, Polk, IA

Built 2016 Load: 34.3 t ADT: 459

NE SANTIAGO DR

Good

Over: CREEK

080222111, Polk, IA

Built 2017 Load: 34.3 t ADT: 300

LOCAL RD

Good

Over: FOUR MILE CREEK

080231800, Polk, IA

Built 1991 Load: 34.3 t ADT: 7,530

NORTH JAMES ST

Good

Over: LITTLE BEAVER CREEK

080252902, Polk, IA

Built 2017 Load: 34.3 t ADT: 1,534

I 29 SB

Good

Over: MOSQUITO CK,RR,BIKE PATH

0.4 MI. S OF JCT. US 275, Pottawattamie, IA

Built 2016 Load: 34.3 t ADT: 10,200

L22

Good

Over: SMALL STREAM

094430202, Sioux, IA

Built 1955 Load: 34.3 t ADT: 366

FM

Good

Over: CREEK

095440801, Sioux, IA

Built 1965 Load: 34.3 t ADT: 2,992

FM

Good

Over: CREEK

095460201, Sioux, IA

Built 1977 Load: 34.3 t ADT: 1,926

LOCAL

Good

Over: SMALL

097440901, Sioux, IA

Built 1978 Load: 34.3 t ADT: 80

LARCH AVE

Good

Over: SMALL

096432102, Sioux, IA

Built 1954 Load: 34.3 t ADT: 20

W AVE

Good

Over: EAST BRANCH SALT CREEK

085132602, Tama, IA

Built 2014 Load: 34.3 t ADT: 26

120TH ST

Good

Over: CREEK

070081801, Van Buren, IA

Built 2012 Load: 34.3 t ADT: 62

HEATHER AVE

Good

Over: CREEK

070100504, Van Buren, IA

Built 2018 Load: 34.3 t ADT: 25

155TH ST

Good

Over: LIME CREEK

077083303, Washington, IA

Built 2013 Load: 34.3 t ADT: 120

LOCAL

Good

Over: STREAM

068213602, Wayne, IA

Built 2000 Load: 34.3 t ADT: 15

LOCAL

Good

Over: DRAINAGE DITCH #34

087280802, Webster, IA

Built 2001 Load: 34.3 t ADT: 123

Showing 12,651-12,700 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.