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

Fair

Over: SMALL STREAM

095462102, Sioux, IA

Built 1939 Load: 20.5 t ADT: 34

LOCAL

Fair

Over: SMALL STREAM

095462802, Sioux, IA

Built 1977 Load: 20.5 t ADT: 34

LOCAL

Fair

Over: SMALL STREAM

095470801, Sioux, IA

Built 1997 Load: 20.5 t ADT: 11

LOCAL

Fair

Over: DRY CREEK

095470802, Sioux, IA

Built 1938 Load: 20.5 t ADT: 11

LOCAL

Fair

Over: SMALL STREAM

095472302, Sioux, IA

Built 1938 Load: 20.5 t ADT: 26

LOCAL

Fair

Over: SIX MILE CREEK

095473001, Sioux, IA

Built 1979 Load: 20.5 t ADT: 26

LOCAL

Fair

Over: SIX MILE CREEK

095473201, Sioux, IA

Built 1979 Load: 20.5 t ADT: 50

LOCAL

Fair

Over: SMALL

096430201, Sioux, IA

Built 1978 Load: 20.5 t ADT: 50

LOCAL

Fair

Over: FLOYD RIVER

096432701, Sioux, IA

Built 1979 Load: 20.5 t ADT: 20

LOCAL

Fair

Over: SMALL

096432902, Sioux, IA

Built 1978 Load: 20.5 t ADT: 15

LOCAL

Fair

Over: SMALL

096440301, Sioux, IA

Built 1979 Load: 20.5 t ADT: 30

LOCAL

Fair

Over: SMALL

096440601, Sioux, IA

Built 1979 Load: 20.5 t ADT: 40

LOCAL

Fair

Over: SMALL STREAM

096453001, Sioux, IA

Built 1947 Load: 20.5 t ADT: 71

LOCAL

Fair

Over: SMALL STREAM

096461501, Sioux, IA

Built 1977 Load: 20.5 t ADT: 34

LOCAL

Fair

Over: SMALL STREAM

096461502, Sioux, IA

Built 1980 Load: 20.5 t ADT: 100

LOCAL

Fair

Over: SMALL STREAM

096463501, Sioux, IA

Built 1938 Load: 20.5 t ADT: 120

LOCAL

Fair

Over: SMALL

096470202, Sioux, IA

Built 1979 Load: 20.5 t ADT: 30

LOCAL

Fair

Over: NO NAME CREEK

096470203, Sioux, IA

Built 1977 Load: 20.5 t ADT: 20

LOCAL

Fair

Over: DRY CREEK

096472501, Sioux, IA

Built 1966 Load: 20.5 t ADT: 40

LOCAL

Fair

Over: SMALL

097450602, Sioux, IA

Built 1941 Load: 20.5 t ADT: 34

LOCAL

Fair

Over: SM STREAM

097450901, Sioux, IA

Built 1933 Load: 20.5 t ADT: 50

LOCAL

Fair

Over: SMALL STREAM

097451002, Sioux, IA

Built 1981 Load: 20.5 t ADT: 60

LOCAL

Fair

Over: SM STREAM

097451502, Sioux, IA

Built 1977 Load: 20.5 t ADT: 40

LOCAL

Fair

Over: SMALL

097461201, Sioux, IA

Built 1978 Load: 20.5 t ADT: 60

LOCAL

Fair

Over: SM STREAM

097462602, Sioux, IA

Built 1977 Load: 20.5 t ADT: 120

FM

Fair

Over: DRY RUN

097471201, Sioux, IA

Built 1977 Load: 20.5 t ADT: 71

LOCAL

Fair

Over: SMALL STREAM

097471302, Sioux, IA

Built 1900 Load: 20.5 t ADT: 110

LOCAL

Fair

Over: SMALL

097473201, Sioux, IA

Built 1995 Load: 20.5 t ADT: 15

FM

Fair

Over: UPPER IOWA RIVER BRANCH

099101302, Winneshiek, IA

Built 1962 Load: 20.5 t ADT: 79

LOCAL

Fair

Over: DD 107

093250902, Wright, IA

Built 1983 Load: 20.5 t ADT: 26

FM

Fair

Over: SMALL

088393101, Ida, IA

Built 1980 Load: 20.6 t ADT: 20

240TH STREET

Fair

Over: HENSCHALL CREEK

076420702, Pottawattamie, IA

Built 1977 Load: 20.6 t ADT: 34

520TH AVE

Fair

Over: WORRELL CREEK

083241610, Story, IA

Built 1966 Load: 20.6 t ADT: 2,324

FM

Fair

Over: OTTER CREEK

083141801, Tama, IA

Built 1930 Load: 20.6 t ADT: 20

LOCAL

Fair

Over: WHISKEY CREEK

089462401, Woodbury, IA

Built 2005 Load: 20.6 t ADT: 20

LOCAL

Fair

Over: BR PATTERSON CREEK

098060404, Allamakee, IA

Built 1977 Load: 20.7 t ADT: 49

LOCAL

Fair

Over: CREEK

081341002, Audubon, IA

Built 1949 Load: 20.7 t ADT: 21

JONQUIL

Fair

Over: W BR BEAVER DAM CREEK

094213404, Cerro Gordo, IA

Built 1955 Load: 20.7 t ADT: 69

450TH ST

Fair

Over: STREAM

094370501, Clay, IA

Built 1949 Load: 20.7 t ADT: 15

LOCAL

Fair

Over: MILLER CREEK

083370405, Crawford, IA

Built 2008 Load: 20.7 t ADT: 15

265TH ST

Fair

Over: STREAM

880328 5050, Delaware, IA

Built 2016 Load: 20.7 t ADT: 70

LATTNERVILLE LANE

Fair

Over: CREEK

089E13104, Dubuque, IA

Built 1955 Load: 20.7 t ADT: 30

LOCAL

Fair

Over: STREAM

078302703, Guthrie, IA

Built 1940 Load: 20.7 t ADT: 50

FM 13TH ST

Fair

Over: PRAIRIE CREEK

084E33103, Jackson, IA

Built 2000 Load: 20.7 t ADT: 246

LOCAL

Fair

Over: DRY RUN

087E30305, Jackson, IA

Built 1978 Load: 20.7 t ADT: 71

LOCAL

Fair

Over: ALPLANOLP CREEK

081172702, Jasper, IA

Built 1992 Load: 20.7 t ADT: 41

LOCAL

Fair

Over: SMALL STREAM

081200806, Jasper, IA

Built 1995 Load: 20.7 t ADT: 16

LOCAL

Fair

Over: NELSON CR

094412502, O'Brien, IA

Built 1938 Load: 20.7 t ADT: 15

410TH ST

Fair

Over: JOHNSON CREEK

095411801, O'Brien, IA

Built 2019 Load: 20.7 t ADT: 21

FM

Fair

Over: W FK W NISHNABOTNA RIVER

079380704, Shelby, IA

Built 1973 Load: 20.7 t ADT: 159

Showing 2,751-2,800 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.