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

280TH STREET

Fair

Over: MIDDLE MILL CREEK

067370901, Page, IA

Built 1988 Load: 32.7 t ADT: 399

P AVENUE

Fair

Over: EAST MILL CREEK

067371502, Page, IA

Built 1997 Load: 32.7 t ADT: 11

290TH STREET

Fair

Over: MIDDLE MILL CREEK

067371601, Page, IA

Built 1988 Load: 32.7 t ADT: 34

OAK AVENUE

Fair

Over: MIDDLE MILL CREEK

067371713, Page, IA

Built 1989 Load: 32.7 t ADT: 29

NUTMEG AVENUE

Fair

Over: MIDDLE MILL CREEK

067372006, Page, IA

Built 1992 Load: 32.7 t ADT: 29

OAK AVENUE

Fair

Over: EAST MILL CREEK

067372104, Page, IA

Built 1988 Load: 32.7 t ADT: 40

280TH STREET

Fair

Over: LONG BRANCH

067381101, Page, IA

Built 1997 Load: 32.7 t ADT: 20

160TH STREET

Fair

Over: STREAM

069370401, Page, IA

Built 1988 Load: 32.7 t ADT: 34

120TH STREET

Fair

Over: STREAM

070361501, Page, IA

Built 1990 Load: 32.7 t ADT: 45

UPLAND AVENUE

Fair

Over: STREAM

070362704, Page, IA

Built 1994 Load: 32.7 t ADT: 20

LUMBER AVENUE

Fair

Over: STREAM

070370704, Page, IA

Built 1990 Load: 32.7 t ADT: 15

105TH STREET

Fair

Over: STREAM

070380205, Page, IA

Built 2005 Load: 32.7 t ADT: 26

F AVENUE

Fair

Over: STREAM

070381802, Page, IA

Built 1986 Load: 32.7 t ADT: 34

V AVENUE

Fair

Over: STREAM

070361102, Page, IA

Built 1987 Load: 32.7 t ADT: 20

FIELD ENT.

Fair

Over: STREAM (SDB)

069371502, Page, IA

Built 1995 Load: 32.7 t ADT: 10

LOCAL

Fair

Over: STREAM

095311201, Palo Alto, IA

Built 1973 Load: 32.7 t ADT: 82

LOCAL

Fair

Over: DD #80

096323501, Palo Alto, IA

Built 1984 Load: 32.7 t ADT: 100

300TH ST

Fair

Over: CYLINDER CREEK

097312201, Palo Alto, IA

Built 2006 Load: 32.7 t ADT: 450

FM

Fair

Over: DRAINAGE DITCH

090432702, Plymouth, IA

Built 1932 Load: 32.7 t ADT: 139

FM

Fair

Over: PERRY CREEK

090470901, Plymouth, IA

Built 1940 Load: 32.7 t ADT: 159

FM

Fair

Over: DRAINAGE DITCH

091432101, Plymouth, IA

Built 1933 Load: 32.7 t ADT: 139

FM

Fair

Over: DRAINAGE

091461202, Plymouth, IA

Built 1966 Load: 32.7 t ADT: 190

FM

Fair

Over: MINNIE CREEK

092452702, Plymouth, IA

Built 1975 Load: 32.7 t ADT: 1,446

FM

Fair

Over: DRAINAGE

092483501, Plymouth, IA

Built 1960 Load: 32.7 t ADT: 669

200TH STREET

Fair

Over: FLOYD RIVER

F22030515, Plymouth, IA

Built 2007 Load: 32.7 t ADT: 8,224

FM

Fair

Over: BR N LIZARD CREEK

092331301, Pocahontas, IA

Built 1982 Load: 32.7 t ADT: 230

FM

Fair

Over: LIZARD CREEK DD#114

092331601, Pocahontas, IA

Built 1982 Load: 32.7 t ADT: 230

LOCAL

Fair

Over: PILOT CREEK

093332401, Pocahontas, IA

Built 2005 Load: 32.7 t ADT: 20

I-80

Fair

Over: MUD CREEK

2.3 MILES E OF JCT US 6, Polk, IA

Built 1959 Load: 32.7 t ADT: 38,700

FM

Fair

Over: DRAINAGE DITCH

078220610, Polk, IA

Built 1967 Load: 32.7 t ADT: 3,605

FM

Fair

Over: MUCHIKINOCK CREEK

079230804, Polk, IA

Built 1967 Load: 32.7 t ADT: 747

FM NE 46TH ST

Fair

Over: MUCHIKINOCK CREEK

080233402, Polk, IA

Built 1990 Load: 32.7 t ADT: 270

NW 5TH ST

Fair

Over: ROCK CREEK

080241606, Polk, IA

Built 1981 Load: 32.7 t ADT: 1,820

LOCAL

Fair

Over: CREEK

081250502, Polk, IA

Built 1987 Load: 32.7 t ADT: 60

LOCAL

Fair

Over: TRIB BIG CREEK

081250301, Polk, IA

Built 1992 Load: 32.7 t ADT: 60

E.P.TRUE PARKWY

Fair

Over: JORDON CREEK

000000000, Polk, IA

Built 1986 Load: 32.7 t ADT: 12,612

GUTHRIE AVE

Fair

Over: OVER UP RR

079243600, Polk, IA

Built 1978 Load: 32.7 t ADT: 5,368

INDIANOLA RD

Fair

Over: YEADER CREEK

078242302, Polk, IA

Built 1986 Load: 32.7 t ADT: 8,570

EP TRUE PARKWAY

Fair

Over: JORDON CREEK

000000000, Polk, IA

Built 1990 Load: 32.7 t ADT: 12,809

NE LAKEVIEW DR

Fair

Over: WATERWAY

080241300, Polk, IA

Built 1994 Load: 32.7 t ADT: 523

DELAWARE AVE

Fair

Over: 7TH WARD DITCH

079242800, Polk, IA

Built 1996 Load: 32.7 t ADT: 5,534

PROSPECT RD

Fair

Over: CLOSES CREEK

Prospect Rd. at Closes Cr, Polk, IA

Built 1984 Load: 32.7 t ADT: 2,245

ARMY POST RD

Fair

Over: ORNERY CREEK

Army Post over Ornery Crk, Polk, IA

Built 1956 Load: 32.7 t ADT: 349

I-235

Fair

Over: DRAINAGE DITCH

0.4 MILE EAST OF IOWA 28, Polk, IA

Built 1966 Load: 32.7 t ADT: 118,600

US 6

Fair

Over: LITTLE KEG CREEK

0.2 MI. W OF SR G-60, Pottawattamie, IA

Built 1968 Load: 32.7 t ADT: 4,110

CO RD G18

Fair

Over: KEG CREEK

077411107, Pottawattamie, IA

Built 1990 Load: 32.7 t ADT: 658

CO RD G18

Fair

Over: MIDDLE SILVER CREEK

077401701, Pottawattamie, IA

Built 1990 Load: 32.7 t ADT: 658

CO RD G18

Fair

Over: SILVER CREEK

077401501, Pottawattamie, IA

Built 1992 Load: 32.7 t ADT: 967

CO RD G18

Fair

Over: WEST NISHNABOTNA RIVER

077391703, Pottawattamie, IA

Built 1975 Load: 32.7 t ADT: 967

IA 92

Fair

Over: JORDAN CREEK

3.5 MI. E OF JCT. 59, Pottawattamie, IA

Built 1932 Load: 32.7 t ADT: 1,180

Showing 6,851-6,900 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.