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: GOWER CREEK

081043208, Cedar, IA

Built 1997 Load: 32.7 t ADT: 950

LOCAL

Good

Over: BR MILL CREEK

082020102, Cedar, IA

Built 1990 Load: 32.7 t ADT: 26

FM

Good

Over: MILL CREEK

082022106, Cedar, IA

Built 2003 Load: 32.7 t ADT: 60

LOCAL

Good

Over: SMALL STREAM

082231, Cedar, IA

Built 1995 Load: 32.7 t ADT: 30

LOCAL

Good

Over: BR PIONEER CR

082030801, Cedar, IA

Built 1998 Load: 32.7 t ADT: 45

FRANKLIN AVE

Good

Over: PIONEER CREEK

082041202, Cedar, IA

Built 2006 Load: 32.7 t ADT: 40

LOCAL

Good

Over: SMALL STREAM

081033208, Cedar, IA

Built 1991 Load: 32.7 t ADT: 30

140TH ST

Good

Over: COLD WATER CREEK

094191801, Cerro Gordo, IA

Built 2006 Load: 32.7 t ADT: 11

MALLARD AVE

Good

Over: BEAVER DAM CREEK

0942007, Cerro Gordo, IA

Built 2012 Load: 32.7 t ADT: 29

JONQUIL

Good

Over: SMALL CREEK

094212702, Cerro Gordo, IA

Built 1981 Load: 32.7 t ADT: 59

140TH ST

Good

Over: W BRANCH BEAVER DAM CRK

0.5 MI E S14, Cerro Gordo, IA

Built 2016 Load: 32.7 t ADT: 35

190TH

Good

Over: E BR BEAVER DAM CREEK

095201901, Cerro Gordo, IA

Built 1982 Load: 32.7 t ADT: 41

INDIGO

Good

Over: BEAVER DAM CREEK

095210902, Cerro Gordo, IA

Built 1998 Load: 32.7 t ADT: 82

340TH

Good

Over: SMALL STREAM

097190401, Cerro Gordo, IA

Built 1982 Load: 32.7 t ADT: 25

295TH

Good

Over: GRAVEL CREEK

097192603, Cerro Gordo, IA

Built 2003 Load: 32.7 t ADT: 51

LARK

Good

Over: WHARAM CREEK

097211202, Cerro Gordo, IA

Built 2005 Load: 32.7 t ADT: 21

DOVE

Good

Over: WILLOW CREEK

097223406, Cerro Gordo, IA

Built 1982 Load: 32.7 t ADT: 47

285TH

Good

Over: SMALL STREAM

097213603, Cerro Gordo, IA

Built 2003 Load: 32.7 t ADT: 47

230TH ST

Good

Over: CRANE CREEK

0962134, Cerro Gordo, IA

Built 2012 Load: 32.7 t ADT: 39

150TH ST

Good

Over: UNNAMED CREEK

0.5 Mi E of S56, Cerro Gordo, IA

Built 2010 Load: 32.7 t ADT: 530

B43 210TH ST

Good

Over: E BR BEAVER DAM CREEK

0.5 Mi W of US65, Cerro Gordo, IA

Built 2006 Load: 32.7 t ADT: 412

FM- V AVE

Good

Over: BRANCH PITCHER CREEK

090391002, Cherokee, IA

Built 1993 Load: 32.7 t ADT: 170

FM- 610TH ST

Good

Over: BRANCH SILVER CREEK

090401101, Cherokee, IA

Built 1995 Load: 32.7 t ADT: 1,017

630TH ST

Good

Over: CREEK

090401901, Cherokee, IA

Built 2005 Load: 32.7 t ADT: 15

C 66 (650TH ST)

Good

Over: STRATTON CREEK

090413401, Cherokee, IA

Built 2012 Load: 32.7 t ADT: 180

M21 V AVE

Good

Over: CREEK

091392201, Cherokee, IA

Built 1993 Load: 32.7 t ADT: 390

LOCAL 540TH ST.

Good

Over: SMALL STREAM

091410403, Cherokee, IA

Built 1987 Load: 32.7 t ADT: 60

520TH ST

Good

Over: BADGER CREEK

092402403, Cherokee, IA

Built 1987 Load: 32.7 t ADT: 170

LOCAL-S AVE.

Good

Over: BADGER CREEK

092402404, Cherokee, IA

Built 1985 Load: 32.7 t ADT: 45

500TH ST

Good

Over: DITCH

092411601, Cherokee, IA

Built 2014 Load: 32.7 t ADT: 15

540TH ST

Good

Over: ROCK CREEK(INTERSECTION)

092413402, Cherokee, IA

Built 1987 Load: 32.7 t ADT: 60

F AVE

Good

Over: W FORK LITTLE SIOUX

092420102, Cherokee, IA

Built 2002 Load: 32.7 t ADT: 399

480TH ST

Good

Over: CREEK

092420203, Cherokee, IA

Built 2005 Load: 32.7 t ADT: 219

FM BARNES RD

Good

Over: STREAM

093391904, Cherokee, IA

Built 1989 Load: 32.7 t ADT: 120

FM 450TH ST

Good

Over: CREEK

093402201, Cherokee, IA

Built 1997 Load: 32.7 t ADT: 319

FM C-16/450TH

Good

Over: CREEK

093391903, Cherokee, IA

Built 2002 Load: 32.7 t ADT: 518

470TH ST

Good

Over: BEAK CREEK

093413301, Cherokee, IA

Built 2018 Load: 32.7 t ADT: 30

FM

Good

Over: SPRING CREEK

094110604, Chickasaw, IA

Built 1988 Load: 32.7 t ADT: 795

LOCAL

Good

Over: SMALL

094111902, Chickasaw, IA

Built 2009 Load: 32.7 t ADT: 82

B66 290TH ST

Good

Over: SPRING CREEK

094112601, Chickasaw, IA

Built 2019 Load: 32.7 t ADT: 5

LOCAL

Good

Over: SMALL STREAM

094113302, Chickasaw, IA

Built 2010 Load: 32.7 t ADT: 30

LOCAL

Good

Over: CREEK

094120901, Chickasaw, IA

Built 2004 Load: 32.7 t ADT: 59

FM

Good

Over: SMALL

094123502, Chickasaw, IA

Built 2009 Load: 32.7 t ADT: 44

LOCAL

Good

Over: SMALL

094130501, Chickasaw, IA

Built 2009 Load: 32.7 t ADT: 26

LOCAL

Good

Over: SPRING BRANCH CREEK

094130801, Chickasaw, IA

Built 2007 Load: 32.7 t ADT: 34

HICKORY

Good

Over: SPRING BRANCH CREEK

094130902, Chickasaw, IA

Built 2023 Load: 32.7 t ADT: 79

250TH ST

Good

Over: TWO MILE CREEK

094140101, Chickasaw, IA

Built 2008 Load: 32.7 t ADT: 26

FM

Good

Over: TWO MILE CREEK

094140102, Chickasaw, IA

Built 1997 Load: 32.7 t ADT: 550

LOCAL

Good

Over: CREEK

094140601, Chickasaw, IA

Built 1996 Load: 32.7 t ADT: 113

LOCAL

Good

Over: CREEK

094143205, Chickasaw, IA

Built 2001 Load: 32.7 t ADT: 16

Showing 11,251-11,300 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.