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

430TH

Fair

Over: BEAVER CREEK

099151901, Mitchell, IA

Built 1953 Load: 22.7 t ADT: 403

420TH

Fair

Over: BIG CEDAR RIVER

099182603, Mitchell, IA

Built 1963 Load: 22.7 t ADT: 422

465TH

Fair

Over: DRAINAGE

100173303, Mitchell, IA

Built 1935 Load: 22.7 t ADT: 619

LOCAL RD

Fair

Over: GARD CREEK

084440810, Monona, IA

Built 1954 Load: 22.7 t ADT: 5

AIRPORT RD-FM

Fair

Over: STREAM

072172605, Monroe, IA

Built 1967 Load: 22.7 t ADT: 390

US 71

Fair

Over: LONG BRANCH CREEK

3.4 mi. N of N jct. H34, Montgomery, IA

Built 1970 Load: 22.7 t ADT: 1,390

LOCAL

Fair

Over: BRANCH BIG SLOUGH CREEK

078043004, Muscatine, IA

Built 1985 Load: 22.7 t ADT: 45

LOCAL SEC RD

Fair

Over: MUD CREEK

094420202, O'Brien, IA

Built 1934 Load: 22.7 t ADT: 103

LOCAL

Fair

Over: LAKE CREEK

095400901, O'Brien, IA

Built 1992 Load: 22.7 t ADT: 21

LOCAL

Fair

Over: LAKE CREEK

095400902, O'Brien, IA

Built 2006 Load: 22.7 t ADT: 30

LOCAL

Fair

Over: SWEENEY CREEK

096 42 02 01, O'Brien, IA

Built 2013 Load: 22.7 t ADT: 50

LOCAL

Fair

Over: FLOYD RIVER OVERFLOW

097421502, O'Brien, IA

Built 1933 Load: 22.7 t ADT: 26

FM

Fair

Over: STREAM

100422002, Osceola, IA

Built 1939 Load: 22.7 t ADT: 60

LOCAL

Fair

Over: CYLINDER CREEK

095311003, Palo Alto, IA

Built 1962 Load: 22.7 t ADT: 72

FM

Fair

Over: STREAM

079161501, Poweshiek, IA

Built 1958 Load: 22.7 t ADT: 410

LOCAL

Fair

Over: SMALL STREAM

087380902, Sac, IA

Built 1986 Load: 22.7 t ADT: 15

LOCAL

Fair

Over: RACCOON RIVER

088361001, Sac, IA

Built 1985 Load: 22.7 t ADT: 20

FM

Fair

Over: RACOON RIVER

088361404, Sac, IA

Built 1970 Load: 22.7 t ADT: 319

305TH ST

Fair

Over: STREAM

080E31003, Scott, IA

Built 1976 Load: 22.7 t ADT: 90

FM

Fair

Over: SALT CREEK

083130904, Tama, IA

Built 1979 Load: 22.7 t ADT: 25

LOCAL

Fair

Over: MIDDLE 102 RIVER

070331501, Taylor, IA

Built 1990 Load: 22.7 t ADT: 20

HARRISON ST

Fair

Over: BR MIDDLE RIVER

076240907, Warren, IA

Built 1949 Load: 22.7 t ADT: 62

LOCAL ROAD

Fair

Over: WALNUT CREEK

074080405, Washington, IA

Built 1962 Load: 22.7 t ADT: 40

LOCAL ROAD

Fair

Over: EAST WALNUT CREEK

074081404, Washington, IA

Built 1968 Load: 22.7 t ADT: 50

LOCAL ROAD

Fair

Over: BURR OAK CREEK

074093603, Washington, IA

Built 1968 Load: 22.7 t ADT: 100

FM

Fair

Over: N. FORK LONG CREEK

076071903, Washington, IA

Built 1970 Load: 22.7 t ADT: 230

LOCAL ROAD

Fair

Over: SMALL STREAM

076091402, Washington, IA

Built 1968 Load: 22.7 t ADT: 40

LOCAL

Fair

Over: SMALL STREAM

076091701, Washington, IA

Built 1967 Load: 22.7 t ADT: 15

LOCAL ROAD

Fair

Over: SMALL STREAM

077082203, Washington, IA

Built 1975 Load: 22.7 t ADT: 15

FM

Fair

Over: LIME CREEK

077082801, Washington, IA

Built 1964 Load: 22.7 t ADT: 60

LK DARLING ST PK

Fair

Over: HONEY CREEK

IN LAKE DARLING ST.PARK, Washington, IA

Built 1929 Load: 22.7 t

LOCAL ROAD

Fair

Over: CANOE CREEK

100081901, Winneshiek, IA

Built 1900 Load: 22.7 t ADT: 26

355TH

Fair

Over: DRAINAGE DITCH

098222503, Worth, IA

Built 1900 Load: 22.7 t ADT: 29

RT E45

Fair

Over: MIDDLE RACCOON RIVER

083341301, Carroll, IA

Built 1974 Load: 22.8 t ADT: 100

LOCAL

Fair

Over: MIDDLE RACCOON RIVER

084351502, Carroll, IA

Built 1970 Load: 22.8 t ADT: 29

LOCAL

Fair

Over: GIZZARD CREEK

094140601, Chickasaw, IA

Built 1997 Load: 22.8 t ADT: 113

FARMERSBURG RD

Fair

Over: ROBERTS CREEK

094051403, Clayton, IA

Built 1933 Load: 22.8 t ADT: 25

LOCAL

Fair

Over: SMALL STREAM

096161304, Floyd, IA

Built 1988 Load: 22.8 t ADT: 78

FM

Fair

Over: LONE GROVE CREEK

080323204, Guthrie, IA

Built 1983 Load: 22.8 t ADT: 20

GROVE AVE

Fair

Over: BR CRANE CREEK

098130604, Howard, IA

Built 1986 Load: 22.8 t ADT: 11

LOCAL

Fair

Over: STONY FORK

073221601, Lucas, IA

Built 1998 Load: 22.8 t ADT: 21

SUNSET AVE

Fair

Over: DD

091430202, Plymouth, IA

Built 1950 Load: 22.8 t ADT: 30

150TH ST

Fair

Over: MINK CREEK

093463301, Plymouth, IA

Built 1961 Load: 22.8 t ADT: 26

IA 92

Fair

Over: GRAYBILL CREEK

1.2 MI. E OF JCT. U.S. 59, Pottawattamie, IA

Built 1957 Load: 22.8 t ADT: 1,180

OLD IA HWY 25

Fair

Over: SMALL STREAM

068313102, Ringgold, IA

Built 1934 Load: 22.8 t ADT: 289

FM

Fair

Over: NORTH RIVER

077301901, Adair, IA

Built 1950 Load: 22.9 t ADT: 131

LOCAL

Fair

Over: LONG BRANCH

067161106, Appanoose, IA

Built 1998 Load: 22.9 t ADT: 16

FM

Fair

Over: BEAVER CREEK

082280301, Boone, IA

Built 1948 Load: 22.9 t ADT: 279

C 33

Fair

Over: SMALL STREAM

092151705, Butler, IA

Built 1966 Load: 22.9 t ADT: 1,002

EVERGREEN AVE

Fair

Over: SMALL STREAM

092181404, Butler, IA

Built 2012 Load: 22.9 t ADT: 16

Showing 3,551-3,600 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.