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 145 ST

Fair

Over: BEAR CREEK

090032803, Delaware, IA

Built 1976 Load: 24.6 t ADT: 78

LOC 120TH AVE

Fair

Over: STREAM

090062804, Delaware, IA

Built 1977 Load: 24.6 t ADT: 26

LOC 150TH ST

Fair

Over: SANDHAGEN CREEK

090063201, Delaware, IA

Built 1976 Load: 24.6 t ADT: 44

M AVE.

Fair

Over: COULEE CREEK

093081804, Fayette, IA

Built 1949 Load: 24.6 t ADT: 97

FM

Fair

Over: BRANCH BEAR CREEK

087183101, Grundy, IA

Built 1964 Load: 24.6 t ADT: 98

LOCAL

Fair

Over: SMALL CREEK

085E43405, Jackson, IA

Built 1992 Load: 24.6 t ADT: 29

SW BLACKHAWK AV

Fair

Over: MILLER CREEK

078081904, Johnson, IA

Built 2004 Load: 24.6 t ADT: 11

BUNKER HILL RD

Fair

Over: BEERS CREEK

084011303, Jones, IA

Built 1981 Load: 24.6 t ADT: 11

BUNKER HILL RD.

Fair

Over: BEERS CREEK

084011305, Jones, IA

Built 1977 Load: 24.6 t ADT: 11

LINN-JONES RD.

Fair

Over: SILVER CREEK

086041802, Jones, IA

Built 1990 Load: 24.6 t ADT: 44

PARIS RD

Fair

Over: WAPSIPINICON RIVER

086062901, Linn, IA

Built 1954 Load: 24.6 t ADT: 344

FM

Fair

Over: ALBERTSON CREEK

0984715, Lyon, IA

Built 1973 Load: 24.6 t ADT: 100

LOCAL

Fair

Over: DRAINAGE

076293301, Madison, IA

Built 1938 Load: 24.6 t ADT: 29

LOCAL

Fair

Over: MUD CREEK

078E10408, Muscatine, IA

Built 1967 Load: 24.6 t ADT: 155

VALLEY WEST DRIVE

Fair

Over: JORDAN CREEK

000000000, Polk, IA

Built 1984 Load: 24.6 t ADT: 11,678

LOCAL

Fair

Over: FLOYD RIV

096431401, Sioux, IA

Built 1954 Load: 24.6 t ADT: 50

FM

Fair

Over: OTTER CREEK 2ND CHANNEL

097441201, Sioux, IA

Built 1962 Load: 24.6 t ADT: 619

LOCAL

Fair

Over: STREAM

086431403, Woodbury, IA

Built 2006 Load: 24.6 t ADT: 50

LOCAL

Fair

Over: SMALL STREAM

091152803, Butler, IA

Built 1967 Load: 24.7 t ADT: 16

LOCAL

Fair

Over: STREAM

082360602, Carroll, IA

Built 1999 Load: 24.7 t ADT: 5

545TH ST

Fair

Over: CLARKS BRANCH

074373104, Cass, IA

Built 2016 Load: 24.7 t ADT: 11

LOCAL

Fair

Over: JACK CREEK

098320901, Emmet, IA

Built 1973 Load: 24.7 t ADT: 20

LOCAL

Fair

Over: DD #40

099320601, Emmet, IA

Built 1973 Load: 24.7 t ADT: 10

FM 210TH ST

Fair

Over: W FORK CEDAR RIVER

093193401, Franklin, IA

Built 1987 Load: 24.7 t ADT: 422

NB I-380

Fair

Over: IOWA RIVER

7.9 MI. N OF JCT I-80, Johnson, IA

Built 1972 Load: 24.7 t ADT: 27,200

LOCAL

Fair

Over: HOWERDON CREEK

076292502, Madison, IA

Built 1992 Load: 24.7 t ADT: 11

FM

Fair

Over: LIZARD CK DD #53

091322301, Pocahontas, IA

Built 1951 Load: 24.7 t ADT: 20

LOCAL

Fair

Over: BIG CEDAR CREEK

092341101, Pocahontas, IA

Built 1956 Load: 24.7 t ADT: 20

LOCAL

Fair

Over: BRANCH IOWA RIVER

081140301, Poweshiek, IA

Built 1951 Load: 24.7 t ADT: 50

LOCAL

Fair

Over: SMALL STREAM

067280105, Ringgold, IA

Built 1990 Load: 24.7 t ADT: 15

LOCAL

Fair

Over: CREEK

082132703, Tama, IA

Built 1950 Load: 24.7 t ADT: 10

FM

Fair

Over: BRANCH IOWA RIVER

083141702, Tama, IA

Built 1990 Load: 24.7 t ADT: 98

FM

Fair

Over: HONEY CREEK

074091707, Washington, IA

Built 1969 Load: 24.7 t ADT: 50

FM

Fair

Over: CAMP CREEK

077072905, Washington, IA

Built 1968 Load: 24.7 t ADT: 120

MARION AVE

Fair

Over: STREAM

074310602, Adair, IA

Built 1992 Load: 24.8 t ADT: 26

NAVAHO AVE

Fair

Over: CRANE CREEK

092121702, Bremer, IA

Built 1994 Load: 24.8 t ADT: 59

MONROE AVE.

Fair

Over: SIBLES CREEK

082020702, Cedar, IA

Built 2003 Load: 24.8 t ADT: 60

310TH

Fair

Over: WINNEBAGO RIVER

097222001, Cerro Gordo, IA

Built 1960 Load: 24.8 t ADT: 992

FM

Fair

Over: BRANCH BEAR CREEK

087183102, Grundy, IA

Built 1966 Load: 24.8 t ADT: 520

FM

Fair

Over: BEAR CREEK ,BRANCH

087183201, Grundy, IA

Built 1964 Load: 24.8 t ADT: 98

LOCAL

Fair

Over: SMALL

078330202, Guthrie, IA

Built 1979 Load: 24.8 t ADT: 20

LOCAL

Fair

Over: SMALL STREAM

078333602, Guthrie, IA

Built 1982 Load: 24.8 t ADT: 11

LOCAL

Fair

Over: LONE GROVE CREEK

079320504, Guthrie, IA

Built 1983 Load: 24.8 t ADT: 20

LOCAL

Fair

Over: TRIB. TO TROUBLESOME

079332102, Guthrie, IA

Built 1977 Load: 24.8 t ADT: 5

LOCAL

Fair

Over: TRIB. TO TROUBLESOME

079332801, Guthrie, IA

Built 1977 Load: 24.8 t ADT: 20

LOCAL

Fair

Over: HONEY CREEK

087222301, Hardin, IA

Built 1980 Load: 24.8 t ADT: 26

FM 335TH ST

Fair

Over: BOYER RIVER

078442301, Harrison, IA

Built 1959 Load: 24.8 t ADT: 788

LOCAL

Fair

Over: ODEBOLT CREEK

087392104, Ida, IA

Built 1981 Load: 24.8 t ADT: 62

LOCAL RD

Fair

Over: STREAM

076120301, Keokuk, IA

Built 1939 Load: 24.8 t ADT: 15

US 59

Fair

Over: STREAM

1.5 mi. N of Jct. IA 48, Page, IA

Built 1930 Load: 24.8 t ADT: 1,780

Showing 4,051-4,100 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.