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

FOREST AVE

Fair

Over: SMALL STREAM

092181202, Butler, IA

Built 2012 Load: 17.5 t ADT: 21

LOCAL

Fair

Over: WEST NISHNABOTNA RIVER

082360902, Carroll, IA

Built 1959 Load: 17.5 t ADT: 60

LOCAL

Fair

Over: SMALL

087E11003, Dubuque, IA

Built 1977 Load: 17.5 t ADT: 30

US 30

Fair

Over: STREAM

2.4 mi. E of SR F-32, Harrison, IA

Built 1924 Load: 17.5 t ADT: 3,090

FM

Fair

Over: EAST FORK CROOKED CREEK

073051501, Henry, IA

Built 1965 Load: 17.5 t ADT: 140

FM

Fair

Over: HONEY CREEK

081122306, Iowa, IA

Built 1960 Load: 17.5 t ADT: 45

ORCHARD AVE

Fair

Over: SUGAR CREEK

079210205, Jasper, IA

Built 1958 Load: 17.5 t ADT: 26

150TH AVE

Fair

Over: SUGAR CREEK

068071202, Lee, IA

Built 1962 Load: 17.5 t ADT: 40

FM

Fair

Over: OTTER CREEK

073030403, Louisa, IA

Built 1959 Load: 17.5 t ADT: 50

LOCAL RD

Fair

Over: NORTH RIVER

076290502, Madison, IA

Built 1962 Load: 17.5 t ADT: 20

LCL-330TH ST

Fair

Over: RAINES BRANCH

072411502, Mills, IA

Built 1955 Load: 17.5 t ADT: 60

FM

Fair

Over: CEDAR CREEK

073190404, Monroe, IA

Built 1963 Load: 17.5 t ADT: 45

LOCAL

Fair

Over: LITTLE WATERMAN CREEK

096402402, O'Brien, IA

Built 1940 Load: 17.5 t ADT: 30

LOCAL

Fair

Over: DEEP CREEK

092430604, Plymouth, IA

Built 1953 Load: 17.5 t ADT: 609

260TH STREET

Fair

Over: STREAM

075420902, Pottawattamie, IA

Built 1992 Load: 17.5 t ADT: 20

LOCAL

Fair

Over: STREAM

068283401, Ringgold, IA

Built 2003 Load: 17.5 t ADT: 26

LOCAL

Fair

Over: FLOYD RIVER

095443602, Sioux, IA

Built 1965 Load: 17.5 t ADT: 199

LOCAL

Fair

Over: SM STREAM

097470101, Sioux, IA

Built 1900 Load: 17.5 t ADT: 34

LOCAL

Fair

Over: CREEK

069330101, Taylor, IA

Built 1950 Load: 17.5 t ADT: 11

LOCAL

Fair

Over: CREEK

068102502, Van Buren, IA

Built 1953 Load: 17.5 t ADT: 47

LOCAL

Fair

Over: EAST MEDICINE CREEK

067212001, Wayne, IA

Built 1982 Load: 17.5 t ADT: 15

RUBY TRAIL

Fair

Over: SIX MILE CREEK

079421210, Harrison, IA

Built 1945 Load: 17.6 t ADT: 26

FM

Fair

Over: SUGAR CREEK

065062401, Lee, IA

Built 1951 Load: 17.6 t ADT: 35

LOCAL

Fair

Over: MIDDLE CREEK

076152504, Mahaska, IA

Built 1965 Load: 17.6 t ADT: 30

LOCAL

Fair

Over: DD 175

095331801, Palo Alto, IA

Built 1921 Load: 17.6 t ADT: 5

160TH ST

Fair

Over: BROKEN KETTLE CREEK

092470401, Plymouth, IA

Built 1964 Load: 17.6 t ADT: 20

FM

Fair

Over: MINK CREEK

093462702, Plymouth, IA

Built 1961 Load: 17.6 t ADT: 628

LOCAL

Fair

Over: SMALL STREAM

086373402, Sac, IA

Built 1922 Load: 17.6 t ADT: 5

550TH AVE

Fair

Over: BALLARD CREEK

082231909, Story, IA

Built 1950 Load: 17.6 t ADT: 110

FM

Fair

Over: SOUTH RIVER

074250102, Warren, IA

Built 1950 Load: 17.6 t ADT: 11

LOCAL

Fair

Over: WEST NISHNABOTNA RIVER

082360301, Carroll, IA

Built 1962 Load: 17.7 t ADT: 40

LOCAL

Fair

Over: WEST NISHNABOTNA RIVER

082360901, Carroll, IA

Built 1965 Load: 17.7 t ADT: 11

FM

Fair

Over: PURGATORY CREEK

084330103, Carroll, IA

Built 1961 Load: 17.7 t ADT: 34

LOCAL

Fair

Over: PURGATORY CREEK

085332501, Carroll, IA

Built 1963 Load: 17.7 t ADT: 29

LOCAL

Fair

Over: HINSON CREEK

071010603, Des Moines, IA

Built 1965 Load: 17.7 t ADT: 11

LOCAL

Fair

Over: HAWKEYE CREEK

072021307, Des Moines, IA

Built 1963 Load: 17.7 t ADT: 16

LOCAL

Fair

Over: STONY CREEK

098382101, Dickinson, IA

Built 1963 Load: 17.7 t ADT: 11

ACORN RD.

Fair

Over: MINK CR

093072404, Fayette, IA

Built 1970 Load: 17.7 t ADT: 44

LOC 370TH ST

Fair

Over: UNION SLOUGH DITCH

098282301, Kossuth, IA

Built 1963 Load: 17.7 t ADT: 26

LOCAL

Fair

Over: CROW CREEK

075211703, Marion, IA

Built 1960 Load: 17.7 t ADT: 35

LOCAL

Fair

Over: STREAM

077212801, Marion, IA

Built 1975 Load: 17.7 t ADT: 123

DOGWOOD AVE

Fair

Over: INDIAN CREEK

093481102, Plymouth, IA

Built 1984 Load: 17.7 t ADT: 11

330TH STREET

Fair

Over: LITTLE SILVER CREEK

076412702, Pottawattamie, IA

Built 1940 Load: 17.7 t ADT: 34

LOCAL

Fair

Over: CEDAR CREEK

072120402, Wapello, IA

Built 1963 Load: 17.7 t ADT: 20

FM

Fair

Over: CEDAR CREEK

073123204, Wapello, IA

Built 1962 Load: 17.7 t ADT: 25

FILBERT AVENUE

Fair

Over: WEST FORK 102 RIVER

071343101, Adams, IA

Built 1972 Load: 17.8 t ADT: 11

FM - 710TH

Fair

Over: WATERWAY

077353604, Cass, IA

Built 1966 Load: 17.8 t ADT: 71

140TH

Fair

Over: BEAVER DAM CREEK

094201801, Cerro Gordo, IA

Built 1923 Load: 17.8 t ADT: 11

LOCAL

Fair

Over: W FK W NISHNABOTNA RVR

083372301, Crawford, IA

Built 2004 Load: 17.8 t ADT: 21

LOCAL

Fair

Over: SMALL STREAM

083372301, Crawford, IA

Built 2004 Load: 17.8 t ADT: 21

Showing 1,951-2,000 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.