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

LOCAL

Fair

Over: SUGAR CREEK BRANCH

068061802, Lee, IA

Built 1949 Load: 24.5 t ADT: 20

FM

Fair

Over: LOST CREEK

069052604, Lee, IA

Built 1975 Load: 24.5 t ADT: 60

FM

Fair

Over: CREEK

069053009, Lee, IA

Built 1958 Load: 24.5 t ADT: 330

LOCAL

Fair

Over: CREEK

069070201, Lee, IA

Built 1950 Load: 24.5 t ADT: 80

LOCAL

Fair

Over: SM STREAM

076051902, Louisa, IA

Built 1970 Load: 24.5 t ADT: 40

LOCAL

Fair

Over: BR OF WHITEBREAST CREEK

072221803, Lucas, IA

Built 1958 Load: 24.5 t ADT: 30

A50 260TH ST

Fair

Over: SMALL STREAM

098483103, Lyon, IA

Built 1968 Load: 24.5 t ADT: 888

FM

Fair

Over: DRY RUN CREEK

099440702, Lyon, IA

Built 1958 Load: 24.5 t ADT: 270

LOCAL ROAD

Fair

Over: EMERY CREEK

099442002, Lyon, IA

Built 1900 Load: 24.5 t ADT: 15

FM

Fair

Over: SMALL STREAM

100442001, Lyon, IA

Built 1978 Load: 24.5 t ADT: 71

LOCAL

Fair

Over: DRAINAGE

077142003, Mahaska, IA

Built 1951 Load: 24.5 t ADT: 30

115TH PL

Fair

Over: TETER CREEK

076201404, Marion, IA

Built 2013 Load: 24.5 t ADT: 26

LOCAL

Fair

Over: WALNUT CREEK

077210301, Marion, IA

Built 1999 Load: 24.5 t ADT: 62

LAMBERT AVE

Fair

Over: SMALL NATURAL STREAM

1.9 mi W of I-29/U.S. #34, Mills, IA

Built 1947 Load: 24.5 t ADT: 468

WALNUT AVE

Fair

Over: SMALL STREAM

099150202, Mitchell, IA

Built 1950 Load: 24.5 t ADT: 462

FM

Fair

Over: WILLOW CREEK

082423308, Monona, IA

Built 1955 Load: 24.5 t ADT: 15

PLUM AVE

Fair

Over: LOCAL STREAM

082432205, Monona, IA

Built 1950 Load: 24.5 t ADT: 40

FM

Fair

Over: BEAVER CR

083441506, Monona, IA

Built 1974 Load: 24.5 t ADT: 150

FM

Fair

Over: STREAM

084433005, Monona, IA

Built 1956 Load: 24.5 t ADT: 40

FM

Fair

Over: WALNUT CREEK TRIB

071392802, Montgomery, IA

Built 1965 Load: 24.5 t ADT: 153

LOCAL

Fair

Over: CREEK

076041406, Muscatine, IA

Built 1948 Load: 24.5 t ADT: 73

LOCAL

Fair

Over: STREAM

099412901, Osceola, IA

Built 1955 Load: 24.5 t ADT: 62

FM

Fair

Over: MINK CREEK

093462702, Plymouth, IA

Built 1961 Load: 24.5 t ADT: 628

7TH STREET

Fair

Over: INDIAN CREEK

7th St over Indian Creek, Pottawattamie, IA

Built 2002 Load: 24.5 t ADT: 1,328

53RD AVE

Fair

Over: CROW CREEK

Bettendorf, IA, Scott, IA

Built 2003 Load: 24.5 t ADT: 6,000

LOCAL

Fair

Over: BUCK CREEK

078370501, Shelby, IA

Built 1950 Load: 24.5 t

260TH ST

Fair

Over: EAST BR INDIAN CREEK

083222701, Story, IA

Built 1912 Load: 24.5 t ADT: 80

590TH AVE

Fair

Over: BEAR CREEK

085232202, Story, IA

Built 1970 Load: 24.5 t ADT: 60

4TH ST

Fair

Over: WALNUT CREEK

B35000505, Story, IA

Built 1974 Load: 24.5 t ADT: 278

FM

Fair

Over: BRANCH IOWA RIVER

084152902, Tama, IA

Built 1949 Load: 24.5 t ADT: 39

LOCAL

Fair

Over: BRANCH WOLF CREEK

085152001, Tama, IA

Built 1987 Load: 24.5 t ADT: 15

FM

Fair

Over: CREEK

070322001, Taylor, IA

Built 1940 Load: 24.5 t ADT: 60

FM

Fair

Over: MIDDLE BRANCH 102 RIVER

070331201, Taylor, IA

Built 1968 Load: 24.5 t ADT: 110

WEBSTER ST

Fair

Over: STREAM

072143500, Wapello, IA

Built 1976 Load: 24.5 t ADT: 969

ADELINE RD

Fair

Over: DRAINAGE

072143607, Wapello, IA

Built 1984 Load: 24.5 t ADT: 118

SO. RANSOM ST

Fair

Over: DRAINAGE

072143600, Wapello, IA

Built 1983 Load: 24.5 t ADT: 165

LOC

Fair

Over: WHITEBREAST CK

074223504, Warren, IA

Built 1991 Load: 24.5 t ADT: 41

WILSON ST

Fair

Over: BRANCH WALNUT CREEK

074253303, Warren, IA

Built 1970 Load: 24.5 t ADT: 11

FM

Fair

Over: GOOSE CREEK

076061804, Washington, IA

Built 1983 Load: 24.5 t ADT: 60

LOCAL

Fair

Over: CROOKED CREEK

076092502, Washington, IA

Built 1987 Load: 24.5 t ADT: 40

FM

Fair

Over: BADGER CREEK

090283004, Webster, IA

Built 1965 Load: 24.5 t ADT: 459

WILLIAMS DRIVE

Fair

Over: SOLDIER CREEK

089291700, Webster, IA

Built 1955 Load: 24.5 t ADT: 1,809

FM

Fair

Over: STREAM

087442104, Woodbury, IA

Built 1958 Load: 24.5 t ADT: 71

LOCAL

Fair

Over: CLEAR CREEK

100052304, Allamakee, IA

Built 1995 Load: 24.6 t ADT: 33

LOCAL

Fair

Over: TRIBUTARY PRAIRIE CREEK

084250304, Boone, IA

Built 1900 Load: 24.6 t ADT: 15

GRANITE AVE

Fair

Over: DRY HOLLOW

094041904, Clayton, IA

Built 1950 Load: 24.6 t ADT: 35

FM 190 AVE

Fair

Over: SMALL STREAM

087050302, Delaware, IA

Built 1968 Load: 24.6 t ADT: 157

LOCAL 200 AVE

Fair

Over: SMALL STREAM

087051104, Delaware, IA

Built 1967 Load: 24.6 t ADT: 49

LOCAL 170 AVE

Fair

Over: SMALL STREAM

087051702, Delaware, IA

Built 1970 Load: 24.6 t ADT: 20

210TH AVE

Fair

Over: SMALL STREAM

087052502, Delaware, IA

Built 1994 Load: 24.6 t ADT: 11

Showing 4,001-4,050 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.