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

FIELD ENTRANCE

Fair

Over: DRAINAGE

074433304, Pottawattamie, IA

Built 1997 Load: 25.6 t ADT: 10

FM

Fair

Over: WALNUT CREEK

078382303, Shelby, IA

Built 1952 Load: 25.6 t ADT: 60

US 18

Fair

Over: WEST FORK FLOYD RIVER

2.0 mi. E of Jct. SR K64, Sioux, IA

Built 1976 Load: 25.6 t ADT: 5,200

527/660TH AVE

Fair

Over: EAST BR INDIAN CREEK

084220202, Story, IA

Built 1962 Load: 25.6 t ADT: 429

LOCAL

Fair

Over: CRYSTAL CREEK

085153102, Tama, IA

Built 1997 Load: 25.6 t ADT: 15

LOCAL

Fair

Over: NORTH RIVER

077303402, Adair, IA

Built 2004 Load: 25.7 t ADT: 21

TEXAS ST

Fair

Over: SINK CREEK

CITY BRIDGENO. 25, Black Hawk, IA

Built 1952 Load: 25.7 t ADT: 1,009

KEYSTONE AVE.

Fair

Over: STREAM

093172602, Butler, IA

Built 1964 Load: 25.7 t ADT: 39

FM - SEATTLE

Fair

Over: SEVEN MILE CREEK

074360503, Cass, IA

Built 1968 Load: 25.7 t ADT: 71

FM - YANKTON

Fair

Over: SEVEN MILE CREEK

074363105, Cass, IA

Built 1974 Load: 25.7 t ADT: 15

LOCAL - HAMBURG

Fair

Over: CREEK

076341003, Cass, IA

Built 1983 Load: 25.7 t ADT: 41

LOCAL - 760TH

Fair

Over: CREEK

076342602, Cass, IA

Built 1983 Load: 25.7 t ADT: 5

LOCAL - HAMBURG

Fair

Over: CREEK

076350203, Cass, IA

Built 1988 Load: 25.7 t ADT: 35

LOCAL - HAMPTON

Fair

Over: SMALL STREAM

076350707, Cass, IA

Built 1986 Load: 25.7 t ADT: 26

FM - 610TH

Fair

Over: TURKEY CREEK

076363204, Cass, IA

Built 1973 Load: 25.7 t ADT: 50

LOCAL - CHICAGO

Fair

Over: WATERWAY

077341403, Cass, IA

Built 1985 Load: 25.7 t ADT: 11

FM

Fair

Over: BROWN CR

099330703, Emmet, IA

Built 1971 Load: 25.7 t ADT: 409

LOCAL

Fair

Over: BROWN CR

100333201, Emmet, IA

Built 1964 Load: 25.7 t ADT: 20

310 AVENUE

Fair

Over: STREAM

070410802, Fremont, IA

Built 1969 Load: 25.7 t ADT: 319

LOCAL

Fair

Over: CREEK

086182501, Grundy, IA

Built 1978 Load: 25.7 t ADT: 44

FM

Fair

Over: BEAVER CREEK

078310406, Guthrie, IA

Built 1968 Load: 25.7 t ADT: 40

FM

Fair

Over: CREEK

088190304, Hardin, IA

Built 1970 Load: 25.7 t ADT: 1,493

FM

Fair

Over: ELK CREEK

088192707, Hardin, IA

Built 1964 Load: 25.7 t ADT: 491

FM-150TH ST

Fair

Over: BRANCH CRANE CREEK

098132201, Howard, IA

Built 1968 Load: 25.7 t ADT: 579

FM

Fair

Over: BLOODY RUN CREEK

093283204, Humboldt, IA

Built 1966 Load: 25.7 t ADT: 450

IA 92

Fair

Over: CLEAR CREEK

2.4 mi. W of Jct SR W15, Keokuk, IA

Built 1967 Load: 25.7 t ADT: 1,560

FM

Fair

Over: TOM CREEK

100432202, Lyon, IA

Built 1980 Load: 25.7 t ADT: 60

FA-BROTHERS AVE

Fair

Over: FARM CREEK

073401201, Mills, IA

Built 1968 Load: 25.7 t ADT: 270

LOCAL

Fair

Over: CREEK

077041801, Muscatine, IA

Built 1967 Load: 25.7 t ADT: 60

FM

Fair

Over: PRAIRIE CREEK

095311401, Palo Alto, IA

Built 1965 Load: 25.7 t ADT: 60

FM

Fair

Over: BR SILVER CREEK

095342401, Palo Alto, IA

Built 1963 Load: 25.7 t ADT: 538

FM

Fair

Over: ROCK CREEK

081133202, Poweshiek, IA

Built 1975 Load: 25.7 t ADT: 50

FM

Fair

Over: CEDAR CREEK

073123102, Wapello, IA

Built 1967 Load: 25.7 t ADT: 810

LOCAL ROAD

Fair

Over: SOUTH FORK LONG CREEK

075071102, Washington, IA

Built 1967 Load: 25.7 t ADT: 30

LOCAL ROAD

Fair

Over: SOUTH FORK LONG CREEK

075071401, Washington, IA

Built 1966 Load: 25.7 t ADT: 50

KIWI AVE

Fair

Over: CLEMONS CREEK

075081404, Washington, IA

Built 1971 Load: 25.7 t ADT: 100

FM

Fair

Over: INDIAN CREEK

075083106, Washington, IA

Built 1968 Load: 25.7 t ADT: 60

LOCAL

Fair

Over: SMALL STREAM

076083001, Washington, IA

Built 1969 Load: 25.7 t ADT: 34

LOCAL ROAD

Fair

Over: SMALL STREAM

077080201, Washington, IA

Built 1966 Load: 25.7 t ADT: 140

HAMILTON BLVD

Fair

Over: PERRY CREEK

000000000, Woodbury, IA

Built 1971 Load: 25.7 t ADT: 18,291

FM

Fair

Over: IOWAY CREEK

085252201, Boone, IA

Built 1963 Load: 25.8 t ADT: 1,108

FM & 194TH ST

Fair

Over: WILLOW RIVER

080432303, Harrison, IA

Built 1968 Load: 25.8 t ADT: 100

FM

Fair

Over: MUD CREEK

068041203, Lee, IA

Built 1965 Load: 25.8 t ADT: 650

NORTH ST

Fair

Over: DRY CREEK

000000000, Linn, IA

Built 1959 Load: 25.8 t ADT: 530

FM

Fair

Over: BUTCHER CREEK

075200402, Marion, IA

Built 1968 Load: 25.8 t ADT: 190

FM

Fair

Over: PINE CREEK

077E11716, Muscatine, IA

Built 1963 Load: 25.8 t ADT: 180

LOCAL

Fair

Over: BRANCH WOLF CREEK

085160501, Tama, IA

Built 1998 Load: 25.8 t ADT: 15

IA 2

Fair

Over: STEELE CREEK

2.0 MI. E OF SR R-69, Wayne, IA

Built 1963 Load: 25.8 t ADT: 930

FM

Fair

Over: DRAINAGE DITCH

099251702, Winnebago, IA

Built 1955 Load: 25.8 t ADT: 90

LOCAL

Fair

Over: BRANCH PAINT CREEK

097041609, Allamakee, IA

Built 1995 Load: 25.9 t ADT: 78

Showing 4,351-4,400 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.