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

FM

Fair

Over: OLD SKUNK RIV CHANNEL

081223006, Polk, IA

Built 1990 Load: 25.2 t ADT: 967

FIELD ENTRANCE

Fair

Over: SIDE DITCH

067341707, Taylor, IA

Built 1900 Load: 25.2 t ADT: 10

FM

Fair

Over: MIDDLE NODAWAY RIVER

074320504, Adair, IA

Built 1967 Load: 25.3 t ADT: 509

FM

Fair

Over: STREAM

077332201, Adair, IA

Built 2001 Load: 25.3 t ADT: 100

LOCAL

Fair

Over: BR WATERLOO CREEK

100061408, Allamakee, IA

Built 1954 Load: 25.3 t ADT: 70

FM

Fair

Over: CREEK

080340502, Audubon, IA

Built 1963 Load: 25.3 t ADT: 26

LOCAL

Fair

Over: E NISHNABOTNA RIVER

081341901, Audubon, IA

Built 1971 Load: 25.3 t ADT: 5

W BENNINGTON RD

Fair

Over: TRIB TO CEDAR RIVER

90-13-21-01-10, Black Hawk, IA

Built 1948 Load: 25.3 t ADT: 29

LOCAL

Fair

Over: COLDWATER CREEK

093180501, Butler, IA

Built 1976 Load: 25.3 t ADT: 44

FM

Fair

Over: NO NAME CREEK

084360602, Carroll, IA

Built 1971 Load: 25.3 t ADT: 728

LOCAL - 670TH

Fair

Over: SEVEN MILE CREEK

075353202, Cass, IA

Built 1978 Load: 25.3 t ADT: 15

LOCAL 550TH ST.

Fair

Over: PERRY CREEK

091400801, Cherokee, IA

Built 1956 Load: 25.3 t ADT: 60

LOC 285 AVE

Fair

Over: SMALL STREAM

087031910, Delaware, IA

Built 1977 Load: 25.3 t ADT: 78

LOC 333RD AVE

Fair

Over: SMALL STREAM

087032508, Delaware, IA

Built 1976 Load: 25.3 t ADT: 97

LOCAL 295 ST

Fair

Over: SMALL STREAM

087051007, Delaware, IA

Built 1987 Load: 25.3 t ADT: 39

LOCAL 200 AVE

Fair

Over: SMALL STREAM

087052602, Delaware, IA

Built 1966 Load: 25.3 t ADT: 70

LOCAL 310 AVE

Fair

Over: STREAM

089032202, Delaware, IA

Built 1966 Load: 25.3 t ADT: 78

LOCAL

Fair

Over: CEDAR FORK

072031704, Des Moines, IA

Built 1962 Load: 25.3 t ADT: 47

ECHO VALLEY RD.

Fair

Over: OTTER CREEK

094082103, Fayette, IA

Built 1971 Load: 25.3 t ADT: 363

RAVEN AVE

Fair

Over: SMALL STREAM

091202310, Franklin, IA

Built 1973 Load: 25.3 t ADT: 26

NB I-35

Fair

Over: FINK CATTLE PASS

0.5 mi. S of Jct. IA 3, Franklin, IA

Built 1973 Load: 25.3 t ADT: 8,250

LOCAL

Fair

Over: MIDDLE FORK BEAVER CREEK

089173002, Grundy, IA

Built 1978 Load: 25.3 t ADT: 5

I 35

Fair

Over: DRAINAGE DITCH

0.8 MILE S OF JCT IA 175, Hamilton, IA

Built 1966 Load: 25.3 t ADT: 27,100

FM

Fair

Over: CREEK

088190204, Hardin, IA

Built 1985 Load: 25.3 t ADT: 5

FM

Fair

Over: BEAVER CREEK

088200804, Hardin, IA

Built 1982 Load: 25.3 t ADT: 15

LOCAL

Fair

Over: BIG CREEK

070051805, Henry, IA

Built 1977 Load: 25.3 t ADT: 62

LOCAL

Fair

Over: BIG MILL CREEK

086E40605, Jackson, IA

Built 1992 Load: 25.3 t ADT: 40

IA 117

Fair

Over: SOUTH SKUNK RIVER

0.7 MILE S OF JCT I-80, Jasper, IA

Built 1967 Load: 25.3 t ADT: 6,300

FM SAND RD

Fair

Over: SNYDER CREEK

078060204, Johnson, IA

Built 1964 Load: 25.3 t ADT: 2,620

RIVER RD.

Fair

Over: SMALL CREEK

086032206, Jones, IA

Built 1976 Load: 25.3 t ADT: 176

URBANA RD

Fair

Over: EAST BLUE CREEK

085080805, Linn, IA

Built 1987 Load: 25.3 t ADT: 1,257

FM

Fair

Over: LONG CREEK

074041804, Louisa, IA

Built 1978 Load: 25.3 t ADT: 40

LOCAL

Fair

Over: SMALL STREAM

075282903, Madison, IA

Built 1986 Load: 25.3 t ADT: 34

FM

Fair

Over: TRIB OF CEDAR CREEK

071190603, Monroe, IA

Built 1963 Load: 25.3 t ADT: 60

LOCAL

Fair

Over: W BR MILL CREEK

096413301, O'Brien, IA

Built 1928 Load: 25.3 t ADT: 15

FM

Fair

Over: SMALL UN-NAMED CREEK

097391202, O'Brien, IA

Built 1935 Load: 25.3 t ADT: 34

IA 9 AT US 59

Fair

Over: BR LITTLE OCHEYEDAN

at the jct. U.S. 59, Osceola, IA

Built 1974 Load: 25.3 t ADT: 2,600

130TH STREET

Fair

Over: E TARKIO RIVER

070372101, Page, IA

Built 1996 Load: 25.3 t ADT: 26

LOCAL

Fair

Over: KEG CREEK

079390702, Shelby, IA

Built 2000 Load: 25.3 t ADT: 41

FM

Fair

Over: WEST NISHNABOTNA RIVER

000000000, Shelby, IA

Built 1969 Load: 25.3 t ADT: 717

LOCAL

Fair

Over: FLOYD RIVER

096432701, Sioux, IA

Built 1979 Load: 25.3 t ADT: 20

LOCAL

Fair

Over: SM STREAM

097430902, Sioux, IA

Built 1960 Load: 25.3 t ADT: 71

FM

Fair

Over: BRANCH SALT CREEK

083141301, Tama, IA

Built 1968 Load: 25.3 t ADT: 59

FM

Fair

Over: ROCK CREEK

085130102, Tama, IA

Built 1968 Load: 25.3 t ADT: 39

FM

Fair

Over: CLEMONS CREEK

075081002, Washington, IA

Built 1956 Load: 25.3 t ADT: 60

FM

Fair

Over: CAMP CR

077072805, Washington, IA

Built 1974 Load: 25.3 t ADT: 120

FM

Fair

Over: BRADYS CREEK

089290104, Webster, IA

Built 1979 Load: 25.3 t ADT: 30

N RAYMOND RD

Fair

Over: CRANE CREEK

90-12-24-02, Black Hawk, IA

Built 1961 Load: 25.4 t ADT: 1,277

330TH ST

Fair

Over: LIME CREEK

087102711, Buchanan, IA

Built 1951 Load: 25.4 t ADT: 992

IA 13

Fair

Over: BRANCH MAQUOKETA RIVER

0.1 mi. N of N jct SR D47, Delaware, IA

Built 1975 Load: 25.4 t ADT: 4,840

Showing 4,251-4,300 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.