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

Poor

Over: STREAM

077180803, Marion, IA

Built 1958 Load: 27.5 t ADT: 62

FM

Poor

Over: WILLOW CREEK

094401502, O'Brien, IA

Built 1964 Load: 27.5 t ADT: 279

290 TH / E57

Poor

Over: SNAKE CREEK

082291103, Greene, IA

Built 1959 Load: 27.6 t ADT: 108

MULBERRY AVENUE

Poor

Over: STREAM

073331704, Adams, IA

Built 1968 Load: 27.7 t ADT: 40

LOCAL

Poor

Over: DD 12

089312801, Calhoun, IA

Built 1974 Load: 27.7 t ADT: 26

330 AVENUE

Poor

Over: MILL CREEK

068413302, Fremont, IA

Built 1956 Load: 27.7 t ADT: 91

LOCAL

Poor

Over: STREAM

078150810, Poweshiek, IA

Built 1918 Load: 27.7 t ADT: 11

E DUNKERTON RD

Poor

Over: WAPSIPINICON RIVER

90-11-35-03, Black Hawk, IA

Built 1964 Load: 27.8 t ADT: 491

HAYES AVE

Poor

Over: ROCK RUN CREEK

081030806, Cedar, IA

Built 1930 Load: 27.8 t ADT: 26

PLUM CREEK ROAD

Poor

Over: PLUM CREEK

070423006, Fremont, IA

Built 1950 Load: 27.8 t ADT: 294

100 TH

Poor

Over: LOST GROVE CREEK

085290401, Greene, IA

Built 1914 Load: 27.8 t ADT: 21

TOLEDO AVE

Poor

Over: PIGEON CREEK

079412702, Harrison, IA

Built 1951 Load: 27.8 t ADT: 34

200TH ST

Poor

Over: BOHEMIAN CREEK

097111306, Howard, IA

Built 1951 Load: 27.8 t ADT: 730

YOUNG AVE

Poor

Over: BOHEMIAN CREEK

097111301, Howard, IA

Built 1951 Load: 27.8 t ADT: 717

E36

Poor

Over: STEIN CREEK

084132401, Tama, IA

Built 1959 Load: 27.8 t ADT: 314

LOCAL

Poor

Over: TWELVE MILE CREEK

086143002, Tama, IA

Built 1985 Load: 27.8 t ADT: 29

LOCAL ROAD

Poor

Over: WHISKEY CREEK

076062604, Washington, IA

Built 1929 Load: 27.8 t ADT: 20

LOCAL

Poor

Over: SMALL CREEK

084E62004, Jackson, IA

Built 1958 Load: 27.9 t ADT: 60

LOCAL

Poor

Over: SMALL STREAM

080182603, Jasper, IA

Built 1918 Load: 27.9 t ADT: 62

140TH AVE

Poor

Over: CREEK

079E32102, Scott, IA

Built 1967 Load: 27.9 t ADT: 26

FM

Poor

Over: WEST 102 RIVER

069353401, Taylor, IA

Built 1986 Load: 27.9 t ADT: 329

LOCAL

Poor

Over: STREAM

089462402, Woodbury, IA

Built 1980 Load: 27.9 t ADT: 60

LOCAL

Poor

Over: DRAINAGE DITCH

087312501, Calhoun, IA

Built 1974 Load: 28.0 t ADT: 5

EUREKA AVE

Poor

Over: MIDDLE BR WAPSININOC CR

079041104, Cedar, IA

Built 1904 Load: 28.0 t ADT: 5

LOCAL

Poor

Over: FOX RIVER

069152303, Davis, IA

Built 1964 Load: 28.0 t ADT: 20

MAGNOLIA ROAD

Poor

Over: STREAM

076392201, Pottawattamie, IA

Built 1961 Load: 28.0 t ADT: 5

LOCAL

Poor

Over: BR NISHNABOTNA

081343001, Audubon, IA

Built 1959 Load: 28.1 t ADT: 26

120TH ST

Poor

Over: CREEK

081361501, Audubon, IA

Built 1941 Load: 28.1 t ADT: 35

FM

Poor

Over: CREEK

080341202, Audubon, IA

Built 1970 Load: 28.1 t ADT: 26

FM

Poor

Over: CEDAR RIVER

080031803, Cedar, IA

Built 1966 Load: 28.1 t ADT: 1,860

FM

Poor

Over: BUCK CREEK

079163503, Poweshiek, IA

Built 1976 Load: 28.1 t ADT: 30

LOCAL ROAD

Poor

Over: SMALL STREAM

076091501, Washington, IA

Built 1927 Load: 28.1 t ADT: 26

FM

Poor

Over: BEAR CREEK

084092603, Benton, IA

Built 1969 Load: 28.2 t ADT: 2,740

LOCAL

Poor

Over: STREAM

093372901, Buena Vista, IA

Built 1973 Load: 28.2 t ADT: 20

A30 460TH ST

Poor

Over: UNION SLOUGH DITCH

099280201, Kossuth, IA

Built 1951 Load: 28.2 t ADT: 170

FM

Poor

Over: LONG BRANCH CREEK

074212602, Marion, IA

Built 1967 Load: 28.2 t ADT: 880

LOCAL

Poor

Over: BRANCH SQUAW CREEK

073251507, Clarke, IA

Built 1980 Load: 28.3 t ADT: 60

ROOSEVELT ST

Poor

Over: BR NORTH WOLF CREEK

074220703, Warren, IA

Built 1945 Load: 28.3 t ADT: 11

FM

Poor

Over: LONG CREEK

070042702, Des Moines, IA

Built 1966 Load: 28.4 t ADT: 690

LOCAL ROAD

Poor

Over: BRANCH OF WOLF CREEK

086172602, Grundy, IA

Built 1976 Load: 28.4 t ADT: 59

LOCAL

Poor

Over: SUGAR CREEK

068071101, Lee, IA

Built 1978 Load: 28.4 t ADT: 11

LOCAL

Poor

Over: STREAM

080163602, Poweshiek, IA

Built 1967 Load: 28.4 t ADT: 11

LOCAL

Poor

Over: CREEK

081340901, Audubon, IA

Built 1941 Load: 28.5 t ADT: 30

LOCAL

Poor

Over: SMALL STREAM

081030703, Cedar, IA

Built 1991 Load: 28.5 t ADT: 15

LOCAL

Poor

Over: HORTON CREEK

094133002, Chickasaw, IA

Built 1981 Load: 28.5 t ADT: 51

LOCAL

Poor

Over: CREEK

094142401, Chickasaw, IA

Built 1975 Load: 28.5 t ADT: 47

LOCAL

Poor

Over: SMALL STREAM

095122902, Chickasaw, IA

Built 1975 Load: 28.5 t ADT: 82

LOCAL

Poor

Over: DEER CREEK

078311304, Guthrie, IA

Built 1947 Load: 28.5 t ADT: 150

FM

Poor

Over: LITTLE ASHER CR

084182202, Marshall, IA

Built 1968 Load: 28.5 t ADT: 432

FM

Poor

Over: SMALL STREAM

081152402, Poweshiek, IA

Built 1968 Load: 28.5 t ADT: 10

Showing 18,801-18,850 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.