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

Structurally Deficient

Over: BR LITTLE SIOUX RIVER

093371802, Buena Vista, IA

Built 1971 ADT: 30

LOCAL

Structurally Deficient

Over: STREAM

093373201, Buena Vista, IA

Built 1973 ADT: 5

FM

Structurally Deficient

Over: BR LITTLE SIOUX RIVER

093381005, Buena Vista, IA

Built 1960 ADT: 26

FM

Structurally Deficient

Over: OVFLW W FORK CEDAR RIVER

090150504, Butler, IA

Built 1953 ADT: 874

LOCAL

Structurally Deficient

Over: BEAVER CREEK

090181402, Butler, IA

Built 1910 ADT: 21

LOCAL

Structurally Deficient

Over: SMALL STREAM

092181403, Butler, IA

Built 1951 ADT: 21

QUAIL AVE

Structurally Deficient

Over: FLOOD CREEK

093162604, Butler, IA

Built 1910 ADT: 26

BLUE BIRD DR.

Structurally Deficient

Over: COLD WATER CREEK

093171304, Butler, IA

Built 1905 ADT: 5

LOCAL

Structurally Deficient

Over: D.D. NO.198

086340101, Calhoun, IA

Built 1900 ADT: 20

LOCAL

Structurally Deficient

Over: DD. NO 31

087310601, Calhoun, IA

Built 1971 ADT: 15

LOCAL

Structurally Deficient

Over: SOUTH BRANCH LIZARD

089310301, Calhoun, IA

Built 1957 ADT: 20

LOCAL

Structurally Deficient

Over: BIG CEDAR CR DD 181

089340401, Calhoun, IA

Built 1900 ADT: 15

LOCAL - 680TH

Structurally Deficient

Over: W NODAWAY RIVER

074351604, Cass, IA

Built 1970 ADT: 62

LOCAL - WICHITA

Structurally Deficient

Over: THREE MILE CREEK

074362603, Cass, IA

Built 1972 ADT: 30

LOCAL - 620TH

Structurally Deficient

Over: WATERWAY

074363302, Cass, IA

Built 1977 ADT: 15

LOCAL - 740TH

Structurally Deficient

Over: WATERWAY

075341602, Cass, IA

Built 1985 ADT: 11

LOCAL - QUINCY

Structurally Deficient

Over: WEST NODAWAY RIVER

075342603, Cass, IA

Built 1982 ADT: 41

FM - 710TH

Structurally Deficient

Over: WATERWAY

076351302, Cass, IA

Built 1955 ADT: 26

LOCAL - 675TH

Structurally Deficient

Over: CREEK

076351704, Cass, IA

Built 1961 ADT: 5

FM - 660TH

Structurally Deficient

Over: JIM CREEK

076351902, Cass, IA

Built 1956 ADT: 34

LOCAL

Structurally Deficient

Over: WATERWAY

076371901, Cass, IA

Built 1955 ADT: 26

LOCAL/EASTLAND

Structurally Deficient

Over: BUCK CREEK

077363001, Cass, IA

Built 1974 ADT: 26

LOCAL/BUCK CRK

Structurally Deficient

Over: EAST NISHNABOTNA RIVER

077363206, Cass, IA

Built 1900 ADT: 123

LOCAL/FAIRVIEW

Structurally Deficient

Over: CREEK

077373601, Cass, IA

Built 1959 ADT: 21

ROSE AVE

Structurally Deficient

Over: SMALL

080021302, Cedar, IA

Built 1979 ADT: 15

270TH ST

Structurally Deficient

Over: CROOKED CR

080023203, Cedar, IA

Built 1930 ADT: 20

LOCAL-640TH ST

Structurally Deficient

Over: MAPLE RIVER

090392801, Cherokee, IA

Built 1954 ADT: 11

Q AVE

Structurally Deficient

Over: BR SILVER CR

090401104, Cherokee, IA

Built 1919 ADT: 11

LOCAL- 630TH ST

Structurally Deficient

Over: WILLOW CREEK

090411901, Cherokee, IA

Built 1917 ADT: 15

LOCAL 540TH ST.

Structurally Deficient

Over: PERRY CREEK

091400501, Cherokee, IA

Built 1982 ADT: 26

LOCAL 550TH ST.

Structurally Deficient

Over: WILLOW CREEK

091410701, Cherokee, IA

Built 1918 ADT: 34

FM J AVE.

Structurally Deficient

Over: ROCK CREEK

091412202, Cherokee, IA

Built 1938 ADT: 11

LOCAL 540TH ST

Structurally Deficient

Over: FIDDLE CREEK

091420501, Cherokee, IA

Built 1900 ADT: 11

LOCAL 440TH ST

Structurally Deficient

Over: CREEK

093411205, Cherokee, IA

Built 1900 ADT: 15

FM J AVE

Structurally Deficient

Over: BEAR CREEK

093411502, Cherokee, IA

Built 1940 ADT: 538

570TH ST

Structurally Deficient

Over: PITCHER 153

091392001, Cherokee, IA

Built 1900 ADT: 11

LOCAL

Structurally Deficient

Over: PLUM CREEK

095120301, Chickasaw, IA

Built 1962 ADT: 62

LOCAL

Structurally Deficient

Over: PLUM CREEK

095121101, Chickasaw, IA

Built 1948 ADT: 16

LOCAL

Structurally Deficient

Over: CRANE CREEK RIVER

096113208, Chickasaw, IA

Built 1951 ADT: 16

LOCAL

Structurally Deficient

Over: LITTLE WAPSIPINICON RVR

096131803, Chickasaw, IA

Built 1952 ADT: 30

LOCAL

Structurally Deficient

Over: WAPSIPINICON RIVER

097142001, Chickasaw, IA

Built 1957 ADT: 21

LOCAL

Structurally Deficient

Over: CHARITON CR

071242406, Clarke, IA

Built 1960 ADT: 15

LOCAL

Structurally Deficient

Over: BR WHITE BREAST CREEK

071251404, Clarke, IA

Built 1969 ADT: 5

LOCAL

Structurally Deficient

Over: WHITE BREAST CREEK

072253503, Clarke, IA

Built 1969 ADT: 11

FM

Structurally Deficient

Over: SOUTH WEST CREEK

072261503, Clarke, IA

Built 1960 ADT: 141

FM

Structurally Deficient

Over: WHITE BREAST CREEK

072262605, Clarke, IA

Built 1975 ADT: 45

LOCAL

Structurally Deficient

Over: CREEK

073240603, Clarke, IA

Built 1954 ADT: 40

FM

Structurally Deficient

Over: OTTER CREEK

073241703, Clarke, IA

Built 1968 ADT: 60

LEG NOT OPEN

Structurally Deficient

Over: SMALL

073260203, Clarke, IA

Built 1975 ADT: 11

LOCAL

Structurally Deficient

Over: SOUTH RIVER

073260508, Clarke, IA

Built 1900 ADT: 11

Showing 19,401-19,450 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.