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

C30 190TH ST

Good

Over: PLYMOUTH CREEK

9244190110, Plymouth, IA

Built 2020 Load: 49.9 t ADT: 789

MARSH AVE

Good

Over: SMALL STREAM

095431202, Sioux, IA

Built 2017 Load: 49.9 t ADT: 30

305TH ST

Good

Over: INDIAN CREEK

082221605, Story, IA

Built 2005 Load: 49.9 t ADT: 80

LOCAL

Good

Over: PRATT CREEK

085110701, Benton, IA

Built 1997 Load: 50.0 t ADT: 26

165TH ST

Good

Over: BUCK CREEK

092110403, Bremer, IA

Built 1998 Load: 50.0 t ADT: 49

FM THOMAS AVE

Good

Over: DRY CREEK

087073106, Buchanan, IA

Built 1989 Load: 50.0 t ADT: 59

LOCAL UNION AVE

Good

Over: DRY CREEK

087073204, Buchanan, IA

Built 1997 Load: 50.0 t ADT: 98

FM

Good

Over: W BR BUFFALO CREEK

090080506, Buchanan, IA

Built 2004 Load: 50.0 t ADT: 334

FM

Good

Over: W BR BUFFALO CR

090081601, Buchanan, IA

Built 2003 Load: 50.0 t ADT: 373

LOC 150TH ST

Good

Over: HUNTER CR

090093103, Buchanan, IA

Built 2006 Load: 50.0 t ADT: 135

LOCAL

Good

Over: RACOON RIVER

092362801, Buena Vista, IA

Built 2004 Load: 50.0 t ADT: 30

FM

Good

Over: EAST CEDAR CREEK

087311001, Calhoun, IA

Built 1996 Load: 50.0 t ADT: 26

LOCAL

Good

Over: BR BIG ELKHORN CREEK

079013503, Cedar, IA

Built 2004 Load: 50.0 t ADT: 35

ROOSEVELT AVE

Good

Over: MILL CR

082020106, Cedar, IA

Built 2005 Load: 50.0 t ADT: 40

LOCAL

Good

Over: SPRING BRANCH

095133502, Chickasaw, IA

Built 2005 Load: 50.0 t ADT: 41

165TH ST

Good

Over: SILVER CREEK

094050505, Clayton, IA

Built 1990 Load: 50.0 t ADT: 137

SPOOK CAVE RD

Good

Over: BLOODY RUN

095042204, Clayton, IA

Built 2004 Load: 50.0 t ADT: 113

FM

Good

Over: SMALL STREAM

082380101, Crawford, IA

Built 2004 Load: 50.0 t ADT: 180

FM

Good

Over: HOCKET CREEK

082380101, Crawford, IA

Built 2004 Load: 50.0 t ADT: 180

FM

Good

Over: JONATHAN CREEK

069240601, Decatur, IA

Built 2003 Load: 50.0 t ADT: 421

180TH AVE

Good

Over: LINDSEY CREEK

090052802, Delaware, IA

Built 2004 Load: 50.0 t ADT: 108

FM

Good

Over: CEDAR FORK FLINT CREEK

072032905, Des Moines, IA

Built 2006 Load: 50.0 t ADT: 1,080

FM WREN AVE

Good

Over: N BEAVER CREEK

090192604, Franklin, IA

Built 2002 Load: 50.0 t ADT: 511

LOCAL RD

Good

Over: BLACK HAWK CREEK

088161402, Grundy, IA

Built 2007 Load: 50.0 t ADT: 29

LOCAL

Good

Over: BLACKHAWK CREEK BRANCH

089153102, Grundy, IA

Built 2004 Load: 50.0 t ADT: 49

LOCAL ROAD

Good

Over: MIDDLE FORK BEAVER CREEK

089182801, Grundy, IA

Built 2006 Load: 50.0 t ADT: 59

LOCAL

Good

Over: TIPTON CREEK

087212603, Hardin, IA

Built 2003 Load: 50.0 t ADT: 30

FM

Good

Over: MIDDLE ENGLISH

078122202, Iowa, IA

Built 2002 Load: 50.0 t ADT: 310

FM

Good

Over: SMALL STREAM

081111202, Iowa, IA

Built 2000 Load: 50.0 t ADT: 1,230

FM

Good

Over: STREAM

076122302, Keokuk, IA

Built 2001 Load: 50.0 t ADT: 680

LOCAL

Good

Over: SHORT CREEK

075051305, Louisa, IA

Built 1995 Load: 50.0 t ADT: 104

FM

Good

Over: BLOOD RUN CREEK

100481201, Lyon, IA

Built 2000 Load: 50.0 t ADT: 439

FM

Good

Over: BURNETT CREEK

084170401, Marshall, IA

Built 1994 Load: 50.0 t ADT: 304

FM

Good

Over: MINERVA CREEK

085200906, Marshall, IA

Built 1997 Load: 50.0 t ADT: 147

M-41 / E AVE

Good

Over: UNAMED CREEK

070393604, Page, IA

Built 2004 Load: 50.0 t ADT: 199

FM C-60

Good

Over: DEEP CREEK

090430801, Plymouth, IA

Built 1990 Load: 50.0 t ADT: 290

300TH ST

Good

Over: DRY BRANCH

090441601, Plymouth, IA

Built 2002 Load: 50.0 t ADT: 45

NOBLE AVE

Good

Over: MUD CREEK

090441902, Plymouth, IA

Built 2002 Load: 50.0 t ADT: 26

FM C-60

Good

Over: BIG WHISKEY CREEK

090450801, Plymouth, IA

Built 2006 Load: 50.0 t ADT: 628

QUARTZ AVE

Good

Over: CLEAR CREEK

091440102, Plymouth, IA

Built 2000 Load: 50.0 t ADT: 30

250TH ST

Good

Over: PERRY CREEK

091472201, Plymouth, IA

Built 2003 Load: 50.0 t ADT: 45

FM

Good

Over: DEER CREEK

091482204, Plymouth, IA

Built 2003 Load: 50.0 t ADT: 429

NOBLE AVE

Good

Over: PLYMOUTH CREEK

092441902, Plymouth, IA

Built 2000 Load: 50.0 t ADT: 80

FM

Good

Over: BULL RUN

092473201, Plymouth, IA

Built 1995 Load: 50.0 t ADT: 838

FM

Good

Over: LITTLE CEDAR CREEK

090340503, Pocahontas, IA

Built 2008 Load: 50.0 t ADT: 34

OLD IA 950 FM

Good

Over: E FOURMILE CK

079233510, Polk, IA

Built 1987 Load: 50.0 t ADT: 8,366

FM

Good

Over: ORANGE CITY SLOUGH

094451501, Sioux, IA

Built 2002 Load: 50.0 t ADT: 823

LOCAL

Good

Over: W BRANCH

095450101, Sioux, IA

Built 1990 Load: 50.0 t ADT: 40

LOCAL

Good

Over: WEST BRANCH

096443101, Sioux, IA

Built 2007 Load: 50.0 t ADT: 20

LOCAL

Good

Over: W BR FLOYD RIVER

096443102, Sioux, IA

Built 2004 Load: 50.0 t ADT: 60

Showing 15,801-15,850 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.