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: ROCK CREEK

081171702, Jasper, IA

Built 1954 Load: 15.9 t ADT: 26

LOCAL

Poor

Over: STREAM

071090103, Jefferson, IA

Built 1953 Load: 15.9 t ADT: 45

FM

Poor

Over: DRAINAGE

072080301, Jefferson, IA

Built 1954 Load: 15.9 t ADT: 50

LOCAL

Poor

Over: BR OF WHITEBREAST CREEK

072222906, Lucas, IA

Built 1951 Load: 15.9 t ADT: 47

LOCAL

Poor

Over: N COAL CREEK

074170204, Mahaska, IA

Built 1955 Load: 15.9 t ADT: 11

LOCAL

Poor

Over: DRAINAGE

075142208, Mahaska, IA

Built 1957 Load: 15.9 t ADT: 30

LOCAL

Poor

Over: SPRING CREEK

075150807, Mahaska, IA

Built 1965 Load: 15.9 t ADT: 120

LOCAL

Poor

Over: ST JOSEPH CREEK

075172507, Mahaska, IA

Built 1959 Load: 15.9 t ADT: 71

FM

Poor

Over: BUCKLEY CREEK

077172707, Mahaska, IA

Built 1956 Load: 15.9 t ADT: 140

LOCAL

Poor

Over: BR WOLF CREEK

085170401, Marshall, IA

Built 1953 Load: 15.9 t ADT: 33

LOCAL

Poor

Over: BR RAVEN CREEK

082171304, Marshall, IA

Built 1986 Load: 15.9 t ADT: 26

LOCAL RD

Poor

Over: BRANCH TARKIO CREEK

073372604, Montgomery, IA

Built 1959 Load: 15.9 t ADT: 15

LOCAL

Poor

Over: CRYSTAL CREEK

084160102, Tama, IA

Built 1951 Load: 15.9 t ADT: 49

FM

Poor

Over: UPPER IOWA RIVER

099083104, Winneshiek, IA

Built 1937 Load: 15.9 t ADT: 324

LOCAL

Poor

Over: WHITE FOX CREEK

090251201, Wright, IA

Built 1968 Load: 15.9 t ADT: 26

LOCAL

Poor

Over: BR BLUE GRASS CREEK

079351008, Audubon, IA

Built 1925 Load: 16.0 t ADT: 21

PARRISH AVE

Poor

Over: PINE CR

088082804, Buchanan, IA

Built 1960 Load: 16.0 t ADT: 82

LOCAL

Poor

Over: DD 13

088323304, Calhoun, IA

Built 1974 Load: 16.0 t ADT: 20

FM

Poor

Over: PEDEE CREEK

079031304, Cedar, IA

Built 1965 Load: 16.0 t ADT: 110

LOCAL

Poor

Over: CREEK

089220801, Hardin, IA

Built 1978 Load: 16.0 t ADT: 15

VICTORY AVE

Poor

Over: UPPER IOWA

100112206, Howard, IA

Built 1949 Load: 16.0 t ADT: 393

FM

Poor

Over: LICK CREEK

071112305, Jefferson, IA

Built 1951 Load: 16.0 t ADT: 120

FM

Poor

Over: STREAM

076121802, Keokuk, IA

Built 1956 Load: 16.0 t ADT: 35

FM

Poor

Over: NORTH RIVER

076281006, Madison, IA

Built 1960 Load: 16.0 t ADT: 100

FM

Poor

Over: IOWA RIVER

083170104, Marshall, IA

Built 1953 Load: 16.0 t ADT: 1,365

LOCAL

Poor

Over: DRAINAGE

072173305, Monroe, IA

Built 1968 Load: 16.0 t ADT: 110

PARK AVE W

Poor

Over: MAD CREEK

000000000, Muscatine, IA

Built 1924 Load: 16.0 t ADT: 184

LOCAL

Poor

Over: LIZARD CREEK

090310302, Pocahontas, IA

Built 1957 Load: 16.0 t ADT: 26

LOCAL

Poor

Over: GRAYBILL CREEK

074390601, Pottawattamie, IA

Built 1950 Load: 16.0 t ADT: 29

MAGNOLIA ROAD

Poor

Over: STREAM

076432003, Pottawattamie, IA

Built 1982 Load: 16.0 t ADT: 11

LOCAL RD

Poor

Over: SMALL

089370801, Sac, IA

Built 1977 Load: 16.0 t ADT: 30

100TH ST

Poor

Over: SUGAR CREEK

072132105, Wapello, IA

Built 1950 Load: 16.0 t ADT: 270

LOCAL RD

Poor

Over: SKILLET CREEK

086271606, Webster, IA

Built 1982 Load: 16.0 t ADT: 50

LOCAL

Poor

Over: MCELHANEY CREEK

089441301, Woodbury, IA

Built 1981 Load: 16.0 t ADT: 20

LOCAL

Poor

Over: SMALL STREAM

070173107, Appanoose, IA

Built 1954 Load: 16.1 t ADT: 91

LOCAL

Poor

Over: LITTLE BEAVER CREEK

082273308, Boone, IA

Built 1939 Load: 16.1 t ADT: 26

LOCAL

Poor

Over: DRAINAGE DITCH

092353202, Buena Vista, IA

Built 1977 Load: 16.1 t ADT: 50

LOCAL-V AVE.

Poor

Over: MAPLE RIVER

092392202, Cherokee, IA

Built 1957 Load: 16.1 t ADT: 34

FM

Poor

Over: SPRING BRANCH

095133501, Chickasaw, IA

Built 1951 Load: 16.1 t ADT: 118

FARM DRIVE

Poor

Over: BRANCH ELK CREEK

097132904, Chickasaw, IA

Built 1974 Load: 16.1 t ADT: 10

FM

Poor

Over: BR WAPSIPINICON RIVER

097142903, Chickasaw, IA

Built 1960 Load: 16.1 t ADT: 29

LOCAL

Poor

Over: STREAM

069123608, Davis, IA

Built 1988 Load: 16.1 t ADT: 11

LOCAL

Poor

Over: MIDDLE RACOON RIVER

079302505, Guthrie, IA

Built 1959 Load: 16.1 t ADT: 71

FM

Poor

Over: SOUTH RACOON RIVER

079302908, Guthrie, IA

Built 1957 Load: 16.1 t ADT: 50

LOCAL

Poor

Over: CREEK

087203503, Hardin, IA

Built 1983 Load: 16.1 t ADT: 41

LOC 210TH ST

Poor

Over: LITTLE PIGEON

080413501, Harrison, IA

Built 1930 Load: 16.1 t ADT: 11

LOCAL

Poor

Over: DICKEY CREEK

071063602, Henry, IA

Built 1956 Load: 16.1 t ADT: 73

LOCAL

Poor

Over: SUGAR CREEK

073072802, Henry, IA

Built 1976 Load: 16.1 t ADT: 41

LOCAL ROAD

Poor

Over: STREAM

074103103, Keokuk, IA

Built 1968 Load: 16.1 t ADT: 20

LOCAL RD

Poor

Over: DRAINAGE

074293505, Madison, IA

Built 1978 Load: 16.1 t ADT: 40

Showing 17,401-17,450 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.