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

140TH ST

Poor

Over: FLOYD RIVER

093452605, Plymouth, IA

Built 1954 Load: 6.4 t ADT: 60

LOCAL

Poor

Over: CREEK

096100403, Winneshiek, IA

Built 1900 Load: 6.4 t ADT: 88

LOCAL

Poor

Over: STREAM

088430602, Woodbury, IA

Built 1950 Load: 6.4 t ADT: 5

FM

Poor

Over: IOWA RIVER OVERFLOW

082132002, Tama, IA

Built 1968 Load: 6.5 t ADT: 786

LOCAL

Poor

Over: SMALL STREAM

069091501, Van Buren, IA

Built 1976 Load: 6.5 t ADT: 26

LOCAL

Poor

Over: BROWN CREEK

100332001, Emmet, IA

Built 1971 Load: 6.8 t ADT: 15

340 AVENUE

Poor

Over: DEER CREEK

070411102, Fremont, IA

Built 1962 Load: 6.8 t ADT: 5

LOCAL

Poor

Over: DD

093293502, Humboldt, IA

Built 1938 Load: 6.8 t ADT: 11

LOCAL

Poor

Over: BRANCH MIDDLE NODAWAY R

074333602, Adair, IA

Built 1960 Load: 6.9 t ADT: 15

COUNTY ROAD

Poor

Over: PANTHER CREEK

079280502, Dallas, IA

Built 1964 Load: 6.9 t ADT: 35

LOCAL

Poor

Over: MCPHERSON CREEK

070430106, Fremont, IA

Built 1979 Load: 6.9 t ADT: 5

LOCAL

Poor

Over: HONEY CREEK

086211402, Hardin, IA

Built 1982 Load: 6.9 t ADT: 29

LCL-QUIGG AVE

Poor

Over: SPRING VALLEY CR

071422605, Mills, IA

Built 1940 Load: 6.9 t ADT: 11

FM

Poor

Over: MILL CREEK

082020104, Cedar, IA

Built 1956 Load: 7.1 t ADT: 550

LOCAL 220 AVE

Poor

Over: STREAM

089043102, Delaware, IA

Built 1967 Load: 7.1 t ADT: 26

LOCAL ROAD

Poor

Over: BRANCH BIG CREEK

072052005, Henry, IA

Built 1977 Load: 7.1 t ADT: 11

BIG CREEK RD.

Poor

Over: BIG CREEK

000000000, Linn, IA

Built 1929 Load: 7.2 t ADT: 130

FARM ENTRANCE

Poor

Over: DRAINAGE DITCH(SDB)

076020702, Muscatine, IA

Built 1920 Load: 7.2 t ADT: 10

LOCAL

Poor

Over: STREAM

089370502, Sac, IA

Built 1960 Load: 7.2 t ADT: 15

LOCAL

Poor

Over: SMALL

097462203, Sioux, IA

Built 1965 Load: 7.2 t ADT: 11

LOCAL

Poor

Over: BOYER RIVER

085382303, Crawford, IA

Built 1980 Load: 7.3 t ADT: 15

ENTRANCE

Poor

Over: SIDE DITCH BRIDGE

094083303, Fayette, IA

Built 1948 Load: 7.3 t ADT: 10

LOCAL ROAD

Poor

Over: WILLIAMS CREEK

073060505, Henry, IA

Built 1966 Load: 7.3 t ADT: 11

S 68TH AVE E

Poor

Over: SLATER CREEK

079183601, Jasper, IA

Built 1927 Load: 7.3 t ADT: 70

LOCAL

Poor

Over: DRAINAGE

077152301, Mahaska, IA

Built 1900 Load: 7.3 t ADT: 5

FM

Poor

Over: NORTH BEAR CREEK

100071502, Winneshiek, IA

Built 1957 Load: 7.3 t ADT: 39

LOCAL

Poor

Over: ELK GROVE BRANCH

080330304, Guthrie, IA

Built 1985 Load: 7.4 t ADT: 34

LOCAL

Poor

Over: CREEK

083190503, Marshall, IA

Built 1917 Load: 7.4 t ADT: 35

LOCAL 540TH ST

Poor

Over: SMALL CREEK

091420103, Cherokee, IA

Built 1919 Load: 7.5 t ADT: 11

LOCAL

Poor

Over: SMALL STREAM

085401102, Crawford, IA

Built 1962 Load: 7.5 t ADT: 26

LOCAL

Poor

Over: STEEL CREEK

068242303, Decatur, IA

Built 1927 Load: 7.5 t ADT: 11

290 STREET

Poor

Over: MILL CREEK

067411501, Fremont, IA

Built 1920 Load: 7.5 t ADT: 15

LOCAL

Poor

Over: HONEY CREEK

086202208, Hardin, IA

Built 1984 Load: 7.5 t ADT: 73

E 132ND ST S

Poor

Over: TURNER CREEK

079170302, Jasper, IA

Built 1928 Load: 7.5 t ADT: 62

LCL-FRY AVE

Poor

Over: MUD CREEK

073413605, Mills, IA

Built 1940 Load: 7.5 t ADT: 26

FM

Poor

Over: STREAM

087353502, Sac, IA

Built 1924 Load: 7.5 t ADT: 50

LOCAL

Poor

Over: DM RIVER

093280503, Humboldt, IA

Built 1911 Load: 7.6 t ADT: 60

RED BRIDGE RD

Poor

Over: BUFFALO CR

086051903, Linn, IA

Built 1900 Load: 7.6 t ADT: 15

LOCAL ROAD

Poor

Over: WOLF CREEK

074221704, Warren, IA

Built 1958 Load: 7.6 t ADT: 30

SUTTON RD

Poor

Over: WAPSIPINICON RIVER

086061904, Linn, IA

Built 1879 Load: 7.7 t ADT: 140

FIR AVE

Poor

Over: BROKEN KETTLE CREEK

092470402, Plymouth, IA

Built 1900 Load: 7.7 t ADT: 30

LOCAL ROAD

Poor

Over: CANOE CREEK

099073304, Winneshiek, IA

Built 1908 Load: 7.7 t ADT: 49

220TH STREET

Poor

Over: EAST NODAWAY RIVER

071340203, Adams, IA

Built 1930 Load: 7.8 t ADT: 33

LOCAL

Poor

Over: BEAVER CREEK

085401102, Crawford, IA

Built 1962 Load: 7.8 t ADT: 26

LOC 100TH AVE

Poor

Over: BLACK CAT CREEK

096291002, Kossuth, IA

Built 1964 Load: 7.8 t ADT: 46

LOCAL

Poor

Over: STREAM

096331002, Palo Alto, IA

Built 1915 Load: 7.8 t ADT: 5

LOCAL

Poor

Over: KEG CREEK

078400606, Shelby, IA

Built 1924 Load: 7.8 t ADT: 20

LOCAL

Poor

Over: MUCHAKINOCK CREEK

076172704, Mahaska, IA

Built 1957 Load: 7.9 t ADT: 100

FM

Poor

Over: SUN VALLEY CREEK

070302502, Ringgold, IA

Built 1961 Load: 7.9 t ADT: 50

FM

Poor

Over: DRAINAGE DITCH

067342703, Taylor, IA

Built 1940 Load: 7.9 t ADT: 26

Showing 16,701-16,750 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.