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

072291008, Union, IA

Built 1985 Load: 17.8 t ADT: 180

FM

Poor

Over: SKUNK RIVER

074091004, Washington, IA

Built 1957 Load: 17.8 t ADT: 120

FM

Poor

Over: COOPER CREEK

068180702, Appanoose, IA

Built 1948 Load: 17.9 t ADT: 120

LOCAL

Poor

Over: KIRKENDALL CREEK

068192704, Appanoose, IA

Built 1950 Load: 17.9 t ADT: 73

LOCAL - UPLAND

Poor

Over: WHISTLERS BRANCH

074351601, Cass, IA

Built 1983 Load: 17.9 t ADT: 5

LOCAL-U AVE

Poor

Over: OVERFLOW CHANNEL

090390902, Cherokee, IA

Built 1925 Load: 17.9 t ADT: 15

LOCAL 570TH ST.

Poor

Over: PERRY CREEK

091401901, Cherokee, IA

Built 1948 Load: 17.9 t ADT: 11

LOCAL

Poor

Over: SMALL STREAM

080301903, Guthrie, IA

Built 1982 Load: 17.9 t ADT: 29

LOCAL

Poor

Over: BREWERS CR

088260304, Hamilton, IA

Built 1926 Load: 17.9 t ADT: 15

LOCAL

Poor

Over: BUCKLEY CREEK

077170503, Mahaska, IA

Built 1929 Load: 17.9 t ADT: 131

LOCAL

Poor

Over: SOUTH TIMBER CREEK

083173201, Marshall, IA

Built 1949 Load: 17.9 t ADT: 34

LOCAL

Poor

Over: BEAVER CREEK

084283301, Boone, IA

Built 1920 Load: 18.0 t ADT: 20

LOCAL

Poor

Over: BROOKS CREEK

092381101, Buena Vista, IA

Built 1924 Load: 18.0 t ADT: 11

FM

Poor

Over: CROOKED CREEK

079020803, Cedar, IA

Built 1923 Load: 18.0 t ADT: 230

FM

Poor

Over: ROCK CREEK

080031603, Cedar, IA

Built 1967 Load: 18.0 t ADT: 1,660

FM 590TH ST.

Poor

Over: ROCK CREEK

091413301, Cherokee, IA

Built 1970 Load: 18.0 t ADT: 45

FM

Poor

Over: LITTLE CEDAR

095142103, Chickasaw, IA

Built 1964 Load: 18.0 t ADT: 579

LOCAL

Poor

Over: SMALL

097122702, Chickasaw, IA

Built 1979 Load: 18.0 t ADT: 91

FM

Poor

Over: TRIBUTARY TO FOX RIVER

069152403, Davis, IA

Built 1970 Load: 18.0 t ADT: 50

FM

Poor

Over: WELDON RIVER

070240903, Decatur, IA

Built 1973 Load: 18.0 t ADT: 26

LOCAL

Poor

Over: DD #40

100323302, Emmet, IA

Built 1968 Load: 18.0 t ADT: 11

2740 URBAN AVE

Poor

Over: DD #13

096230404, Hancock, IA

Built 1969 Load: 18.0 t ADT: 15

198TH ST

Poor

Over: SMALL CREEK

080422211, Harrison, IA

Built 1950 Load: 18.0 t ADT: 79

FM

Poor

Over: GRITTER CREEK

078123602, Iowa, IA

Built 1970 Load: 18.0 t ADT: 15

LOCAL

Poor

Over: SMALL STREAM

081180401, Jasper, IA

Built 1952 Load: 18.0 t ADT: 16

LOCAL ROAD

Poor

Over: OVERFLOW

098472601, Lyon, IA

Built 1900 Load: 18.0 t ADT: 21

LOCAL RD

Poor

Over: W BR GRAND RIVER

074293005, Madison, IA

Built 1951 Load: 18.0 t ADT: 20

LOCAL

Poor

Over: MUCHAKINOCH CREEK

075160703, Mahaska, IA

Built 1951 Load: 18.0 t ADT: 50

PARKER AVE

Poor

Over: SOUTH TIMBER CREEK

082181004, Marshall, IA

Built 1950 Load: 18.0 t ADT: 21

LOCAL

Poor

Over: NORTH TIMBER CREEK

083191902, Marshall, IA

Built 1951 Load: 18.0 t ADT: 30

LOCAL

Poor

Over: NORTH TIMBER CREEK

083192102, Marshall, IA

Built 1950 Load: 18.0 t ADT: 5

LOCAL

Poor

Over: MINERVA CR

084190602, Marshall, IA

Built 1946 Load: 18.0 t ADT: 30

FM

Poor

Over: STREAM

073170803, Monroe, IA

Built 1951 Load: 18.0 t ADT: 70

LOCAL

Poor

Over: DD 98

094331401, Palo Alto, IA

Built 1972 Load: 18.0 t ADT: 21

MARBLE AVE.

Poor

Over: PLYMOUTH CREEK

092453502, Plymouth, IA

Built 1946 Load: 18.0 t ADT: 5

LOCAL

Poor

Over: E FORK GRAND RIVER

070291201, Ringgold, IA

Built 1969 Load: 18.0 t ADT: 5

FM

Poor

Over: OUTLET GREEN VALLEY LK

073312601, Union, IA

Built 1951 Load: 18.0 t ADT: 159

LOCAL

Poor

Over: SM STREAM

077090103, Washington, IA

Built 1974 Load: 18.0 t ADT: 40

LOCAL

Poor

Over: UPPER IOWA RIVER

098070906, Winneshiek, IA

Built 1900 Load: 18.0 t ADT: 70

POPLAR AVENUE

Poor

Over: STREAM

073332602, Adams, IA

Built 1983 Load: 18.1 t ADT: 29

WELLMAN RD

Poor

Over: TRIB TO SPRING CREEK

87-11-10-01-10, Black Hawk, IA

Built 1968 Load: 18.1 t ADT: 15

LOCAL - 765TH

Poor

Over: WATERWAY

076341104, Cass, IA

Built 1900 Load: 18.1 t ADT: 35

STONE MILL RD

Poor

Over: ROCK RUN CREEK

080032203, Cedar, IA

Built 1974 Load: 18.1 t ADT: 50

FM

Poor

Over: HAWKEYE DOLBEE CHANNEL

072012002, Des Moines, IA

Built 1953 Load: 18.1 t ADT: 25

FM TULIP AVE

Poor

Over: W FORK CEDAR CRK OVRFLW

093192804, Franklin, IA

Built 1960 Load: 18.1 t ADT: 137

305 AVENUE

Poor

Over: DRISCALL CREEK

070410706, Fremont, IA

Built 1958 Load: 18.1 t ADT: 63

LOCAL 25TH ST

Poor

Over: UPPER IOWA RIVER

100131303, Howard, IA

Built 1880 Load: 18.1 t ADT: 26

LOCAL

Poor

Over: SMALL

080112001, Iowa, IA

Built 1978 Load: 18.1 t ADT: 11

LOCAL

Poor

Over: STREAM

077102204, Keokuk, IA

Built 1969 Load: 18.1 t ADT: 26

LOCAL

Poor

Over: BRANCH N TIMBER CREEK

083192603, Marshall, IA

Built 1920 Load: 18.1 t ADT: 30

Showing 17,751-17,800 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.