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 ROAD

Fair

Over: MOON CREEK

100463601, Lyon, IA

Built 1900 Load: 23.9 t ADT: 62

LOCAL

Fair

Over: FLY CREEK

076213108, Marion, IA

Built 1976 Load: 23.9 t ADT: 41

LOCAL

Fair

Over: STREAM

077200204, Marion, IA

Built 1997 Load: 23.9 t ADT: 26

LCL-325TH ST

Fair

Over: CREEK

072412104, Mills, IA

Built 1967 Load: 23.9 t ADT: 71

SUNSET AVE

Fair

Over: DD

091432302, Plymouth, IA

Built 1956 Load: 23.9 t ADT: 15

PIONEER AVE

Fair

Over: DRAINAGE

092440302, Plymouth, IA

Built 1991 Load: 23.9 t ADT: 30

FM-JUNIPER ROAD

Fair

Over: LITTLE WALNUT CREEK

076383301, Pottawattamie, IA

Built 1954 Load: 23.9 t ADT: 20

SYCAMORE ROAD

Fair

Over: SILVER CREEK

077403001, Pottawattamie, IA

Built 1940 Load: 23.9 t ADT: 15

LOCAL

Fair

Over: E FK GRAND RIVER

069290101, Ringgold, IA

Built 1958 Load: 23.9 t ADT: 11

LOCAL

Fair

Over: E FK GRAND RIVER

069293507, Ringgold, IA

Built 1989 Load: 23.9 t ADT: 29

LOCAL

Fair

Over: BRANCH OF SALT CREEK

082130206, Tama, IA

Built 1991 Load: 23.9 t ADT: 33

LOCAL

Fair

Over: WOLF CREEK

083131806, Tama, IA

Built 1940 Load: 23.9 t ADT: 70

FM

Fair

Over: BRANCH MIDDLE 102 RIVER

068341601, Taylor, IA

Built 1999 Load: 23.9 t ADT: 15

LOCAL

Fair

Over: SMALL

070331301, Taylor, IA

Built 1980 Load: 23.9 t ADT: 34

JESUP ST

Fair

Over: FELTERS BRANCH

076243001, Warren, IA

Built 2013 Load: 23.9 t ADT: 91

LOCAL

Fair

Over: SMALL STREAM

088421201, Woodbury, IA

Built 1986 Load: 23.9 t ADT: 15

FM

Fair

Over: WILLIAMS CREEK

096050808, Allamakee, IA

Built 1958 Load: 24.0 t ADT: 589

LOCAL

Fair

Over: CREEK

092113102, Bremer, IA

Built 1996 Load: 24.0 t ADT: 59

LOC 302 ST

Fair

Over: SMALL STREAM

087031403, Delaware, IA

Built 1964 Load: 24.0 t ADT: 49

LOC 325TH ST

Fair

Over: SMALL STREAM

087042703, Delaware, IA

Built 2001 Load: 24.0 t ADT: 33

LOCAL 130 AVE

Fair

Over: SMALL STREAM

088063402, Delaware, IA

Built 1967 Load: 24.0 t ADT: 11

LOCAL

Fair

Over: WHITE WATER CREEK

087010103, Dubuque, IA

Built 1982 Load: 24.0 t ADT: 71

US 20 & IA 17

Fair

Over: WATERWAY

2.1 MI E OF W JCT IA 17, Hamilton, IA

Built 1977 Load: 24.0 t ADT: 11,200

LOCAL 115TH ST

Fair

Over: TURKEY CREEK

099113107, Howard, IA

Built 1987 Load: 24.0 t ADT: 59

IRIS AVE

Fair

Over: BEAVER CREEK

099130402, Howard, IA

Built 1951 Load: 24.0 t ADT: 30

FM

Fair

Over: MAQUOKETA RIVER

084E21307, Jackson, IA

Built 1966 Load: 24.0 t ADT: 1,170

95TH ST.

Fair

Over: SMALL STREAM

084032003, Jones, IA

Built 1982 Load: 24.0 t ADT: 51

LOCAL

Fair

Over: W BR MILL CREEK

096413201, O'Brien, IA

Built 1947 Load: 24.0 t ADT: 30

S 35TH ST

Fair

Over: STREAM

000000000, Polk, IA

Built 1991 Load: 24.0 t ADT: 1,252

ROSEWOOD ROAD

Fair

Over: KEG CREEK

076410401, Pottawattamie, IA

Built 1976 Load: 24.0 t ADT: 20

FM-SYCAMORE RD

Fair

Over: PIGEON CREEK

077423001, Pottawattamie, IA

Built 1958 Load: 24.0 t ADT: 45

LOCAL

Fair

Over: SMALL STREAM

095443602, Sioux, IA

Built 1965 Load: 24.0 t ADT: 199

LOCAL

Fair

Over: SMALL STREAM

095471402, Sioux, IA

Built 1963 Load: 24.0 t ADT: 5

LOCAL

Fair

Over: SMALL STREAM

096432701, Sioux, IA

Built 1965 Load: 24.0 t ADT: 20

FM

Fair

Over: DRY CREEK

096450701, Sioux, IA

Built 1965 Load: 24.0 t ADT: 60

LOCAL

Fair

Over: PLATTE BRANCH

068323103, Taylor, IA

Built 1989 Load: 24.0 t ADT: 5

LOCAL

Fair

Over: CREEK

096071701, Winneshiek, IA

Built 1900 Load: 24.0 t ADT: 29

EB US 20

Fair

Over: BLACKHAWK CREEK

0.7 MI. W OF JCT. US 63, Black Hawk, IA

Built 1983 Load: 24.1 t ADT: 12,400

FM

Fair

Over: FIELD STREAM

082341304, Carroll, IA

Built 1951 Load: 24.1 t ADT: 45

LOCAL

Fair

Over: SOUTH OTTER CREEK

072230602, Lucas, IA

Built 1998 Load: 24.1 t ADT: 5

IA 144

Fair

Over: EAST BUTTRICK CREEK

2.2 mi S of IA 175, Webster, IA

Built 1955 Load: 24.1 t ADT: 670

LOCAL

Fair

Over: STREAM

089420401, Woodbury, IA

Built 1955 Load: 24.1 t ADT: 26

FM

Fair

Over: STREAM

074323506, Adair, IA

Built 1950 Load: 24.2 t ADT: 40

FM-UNION AVENUE

Fair

Over: STREAM

072323402, Adams, IA

Built 1960 Load: 24.2 t ADT: 34

B15 330TH ST

Fair

Over: SPRING CREEK

097200903, Cerro Gordo, IA

Built 1957 Load: 24.2 t ADT: 570

B-15

Fair

Over: BEAVER CREEK

000000000, Cerro Gordo, IA

Built 1957 Load: 24.2 t ADT: 579

130TH

Fair

Over: COLDWATER CREEK

094192001, Cerro Gordo, IA

Built 1974 Load: 24.2 t ADT: 11

INDIGO

Fair

Over: W FORK BEAVER DAM CREEK

094210902, Cerro Gordo, IA

Built 1940 Load: 24.2 t ADT: 16

200TH

Fair

Over: BEAVER DAM CREEK

095211601, Cerro Gordo, IA

Built 1918 Load: 24.2 t ADT: 5

250TH

Fair

Over: WINNEBAGO RIVER

096191903, Cerro Gordo, IA

Built 1923 Load: 24.2 t ADT: 51

Showing 3,801-3,850 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.