State profile · Above median Poor share

Iowa bridge safety

Condition ratings, load ratings, and Poor-condition data for every public highway bridge in Iowa, based on the FHWA National Bridge Inventory.

20,753
Public bridges
36.5%
Good condition
20.0%
Poor condition

Data updated May 2026

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 whose lowest applicable component is rated 0-4

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 - Poor-condition share 66.7%
National avg

Lower is better. Bar maxes at 30% (worst-state ceiling). National average sits at 7.0%.

Condition Distribution

Iowa38.5%40.4%21.1%GoodFairPoor
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 by Poor-condition share (lower share = better)

States are ranked by the share of bridges whose lowest applicable component rating is 4 or below. This describes recorded condition; it does not measure funding effectiveness or live crossing safety. States here sit immediately above and below Iowa on the same metric.

WV

West Virginia

16.02% top marginal rate
Structure
Progressive
Burden @ $100K
$7,679

SD

South Dakota

16.24% top marginal rate
Structure
Progressive
Burden @ $100K
$5,905
Selected

IA

Iowa

20.01% top marginal rate
Structure
Progressive
Burden @ $100K
$20,753

VI

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 the portal's composite display score. Inspection intervals are risk-based under current NBIS rules.

270TH STREET

Poor

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

Poor

Over: MUD CREEK

87-12-15-02-10, Black Hawk, IA

Built 1948 Load: 2.7 t ADT: 11

LOCAL - 700TH

Poor

Over: TRIB TROUBLESOME CREEK

077351402, Cass, IA

Built 1983 Load: 2.7 t ADT: 11

LOCAL - DAYTONA

Poor

Over: BUCK CREEK

077361903, Cass, IA

Built 1980 Load: 2.7 t ADT: 35

100TH ST.

Poor

Over: UNION CREEK

083E20101, Clinton, IA

Built 1900 Load: 2.7 t ADT: 78

All Bridges in Iowa

LOCAL ROAD

Poor

Over: CREEK

087151304, Grundy, IA

Built 1977 Load: 21.7 t ADT: 15

MARTIN CR.RD.

Poor

Over: MARTINS CR

083061105, Linn, IA

Built 1972 Load: 21.7 t ADT: 120

HILLS MILL RD

Poor

Over: BUFFALO CREEK

086052912, Linn, IA

Built 1940 Load: 21.7 t ADT: 88

R AVENUE

Poor

Over: STREAM

068371204, Page, IA

Built 1980 Load: 21.7 t ADT: 26

200TH ST

Poor

Over: CLEAR CREEK

092433003, Plymouth, IA

Built 1946 Load: 21.7 t ADT: 5

515TH STREET

Poor

Over: STREAM

077382206, Pottawattamie, IA

Built 1991 Load: 21.7 t ADT: 5

LOCAL

Poor

Over: LONG BRANCH

801637, Shelby, IA

Built 1940 Load: 21.7 t ADT: 51

LOCAL

Poor

Over: SALT CREEK

085143002, Tama, IA

Built 1910 Load: 21.7 t ADT: 15

J35

Poor

Over: DRAINAGE DITCH

069332801, Taylor, IA

Built 1938 Load: 21.7 t ADT: 210

FIELD ENTRANCE

Poor

Over: STREAM (SDB)

069201906, Wayne, IA

Built 1900 Load: 21.7 t ADT: 10

FM

Poor

Over: WEST FORK LITTLE SIOUX

087451605, Woodbury, IA

Built 1955 Load: 21.7 t ADT: 429

FM

Poor

Over: ROCK CREEK

082031504, Cedar, IA

Built 1958 Load: 21.8 t ADT: 60

LOCAL 430TH ST

Poor

Over: CREEK

093401003, Cherokee, IA

Built 1936 Load: 21.8 t ADT: 20

LOCAL

Poor

Over: LOCAL CREEK

071250304, Clarke, IA

Built 1968 Load: 21.8 t ADT: 20

FM

Poor

Over: STREAM

068142404, Davis, IA

Built 1966 Load: 21.8 t ADT: 480

FM

Poor

Over: WINNEBAGO RIVER

096183108, Floyd, IA

Built 1964 Load: 21.8 t ADT: 442

LOCAL ROAD

Poor

Over: MUNNS CREEK

087162102, Grundy, IA

Built 1971 Load: 21.8 t ADT: 29

LOCAL

Poor

Over: STREAM

078300302, Guthrie, IA

Built 1943 Load: 21.8 t ADT: 20

FM

Poor

Over: DRAINAGE DITCH

089231006, Hamilton, IA

Built 1960 Load: 21.8 t ADT: 319

S 112TH AVE W

Poor

Over: PRAIRIE CREEK

078212503, Jasper, IA

Built 1950 Load: 21.8 t ADT: 47

LOCAL

Poor

Over: SMALL STREAM

081171701, Jasper, IA

Built 1948 Load: 21.8 t ADT: 11

LOCAL

Poor

Over: LINN CR

084193002, Marshall, IA

Built 1945 Load: 21.8 t ADT: 44

LOCAL

Poor

Over: LITTLE ASHER CR

085181504, Marshall, IA

Built 1984 Load: 21.8 t ADT: 39

LOCAL

Poor

Over: DRAINAGE

074380401, Pottawattamie, IA

Built 1995 Load: 21.8 t ADT: 11

LOCAL

Poor

Over: PIGEON CREEK

803140, Shelby, IA

Built 1947 Load: 21.8 t

FM

Poor

Over: HOG BRANCH

069320804, Taylor, IA

Built 1975 Load: 21.8 t ADT: 390

FM

Poor

Over: N. FORK LONG CREEK

076073304, Washington, IA

Built 1961 Load: 21.8 t ADT: 440

LOCAL

Poor

Over: UPPER IOWA RIVER

098081206, Winneshiek, IA

Built 1985 Load: 21.8 t ADT: 207

LOCAL - AKRON

Poor

Over: SMALL STREAM

077340401, Cass, IA

Built 1987 Load: 21.9 t ADT: 11

130TH ST

Poor

Over: MILL CR

082022201, Cedar, IA

Built 1930 Load: 21.9 t ADT: 20

160TH ST

Poor

Over: UNAMED CREEK

093092301, Fayette, IA

Built 1970 Load: 21.9 t ADT: 33

LOC 160TH ST

Poor

Over: PRAIRIE CREEK

094270501, Kossuth, IA

Built 1986 Load: 21.9 t ADT: 5

LOC 170TH ST

Poor

Over: DRAINAGE DITCH NO 9

095303601, Kossuth, IA

Built 1977 Load: 21.9 t ADT: 21

FM

Poor

Over: DRAINAGE

077271501, Madison, IA

Built 1960 Load: 21.9 t ADT: 40

LOCAL

Poor

Over: PILOT CREEK

093330102, Pocahontas, IA

Built 1975 Load: 21.9 t ADT: 30

LOCAL

Poor

Over: N LIZARD CREEK

093340101, Pocahontas, IA

Built 1974 Load: 21.9 t ADT: 20

LOCAL

Poor

Over: SMALL STREAM

086373102, Sac, IA

Built 1971 Load: 21.9 t ADT: 26

LOCAL

Poor

Over: SMALL STREAM

073303401, Union, IA

Built 1992 Load: 21.9 t ADT: 21

FM

Poor

Over: SMALL STREAM

077061903, Washington, IA

Built 1925 Load: 21.9 t ADT: 270

LOCAL

Poor

Over: DRAINAGE DITCH

098240301, Winnebago, IA

Built 1928 Load: 21.9 t ADT: 82

D-25

Poor

Over: ELLIOT CREEK

088463110, Woodbury, IA

Built 1957 Load: 21.9 t ADT: 977

EDLORA RD

Poor

Over: TRIB TO BLACK HAWK CREEK

87-14-05-03-10, Black Hawk, IA

Built 1947 Load: 22.0 t ADT: 59

LOCAL PHEASANT

Poor

Over: SMALL STREAM

087041303, Delaware, IA

Built 1973 Load: 22.0 t ADT: 97

LOCAL 215 AVE

Poor

Over: SMALL STREAM

087052504, Delaware, IA

Built 1965 Load: 22.0 t ADT: 11

FM 280 AVE

Poor

Over: SMALL STREAM

090033002, Delaware, IA

Built 1973 Load: 22.0 t ADT: 79

LOCAL

Poor

Over: STREAM

087011804, Dubuque, IA

Built 1981 Load: 22.0 t ADT: 90

LOCAL

Poor

Over: SMALL

081332004, Guthrie, IA

Built 1979 Load: 22.0 t ADT: 26

STONE CITY RD.

Poor

Over: CROW CREEK

084040603, Jones, IA

Built 1975 Load: 22.0 t ADT: 295

LOCAL

Poor

Over: DRAINAGE

076293602, Madison, IA

Built 1960 Load: 22.0 t ADT: 26

LOCAL

Poor

Over: DRAINAGE

077280202, Madison, IA

Built 1955 Load: 22.0 t ADT: 131

Showing 19,501-19,550 of 20,753 bridges

Related

All states → | National rankings → | Understanding conditions → | Retired SD term explained →
Data sourced from the FHWA National Bridge Inventory (NBI), latest released cycle. See our methodology for details. Retrieved and formatted by PlainBridges.

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). Poor condition is an inspection-record category, not a closure or unsafe-to-cross designation. Consult the bridge owner for current status.

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.

Every figure on PlainBridge is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.