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

160TH ST

Fair

Over: STREAM

092140301, Bremer, IA

Built 1998 Load: 26.7 t ADT: 33

160TH ST

Fair

Over: STREAM

092140601, Bremer, IA

Built 1997 Load: 26.7 t ADT: 78

110TH ST

Fair

Over: STREAM

093111001, Bremer, IA

Built 1997 Load: 26.7 t ADT: 33

FM

Fair

Over: CREEK

096131302, Chickasaw, IA

Built 2006 Load: 26.7 t ADT: 79

LOCAL

Fair

Over: HONEY CREEK

086210302, Hardin, IA

Built 1963 Load: 26.7 t ADT: 16

80TH AVE.

Fair

Over: LITTLE BEAR CREEK

084021302, Jones, IA

Built 1957 Load: 26.7 t ADT: 16

LCL-350TH ST

Fair

Over: STREAM

071410204, Mills, IA

Built 1964 Load: 26.7 t ADT: 26

LCL-295TH ST

Fair

Over: CREEK

072420104, Mills, IA

Built 1963 Load: 26.7 t ADT: 11

435TH STREET

Fair

Over: STREAM

076391708, Pottawattamie, IA

Built 1995 Load: 26.7 t ADT: 40

S27/650TH AVE

Fair

Over: CALAMUS CREEK

082223404, Story, IA

Built 1962 Load: 26.7 t ADT: 540

FM

Fair

Over: TURKEY RIVER

098102101, Winneshiek, IA

Built 1956 Load: 26.7 t ADT: 766

230TH ST

Fair

Over: SMALL STREAM

098103407, Winneshiek, IA

Built 1974 Load: 26.7 t ADT: 26

JASPER AVE

Fair

Over: MC ELHANEY CREEK

089442402, Woodbury, IA

Built 2003 Load: 26.7 t ADT: 15

LOCAL

Fair

Over: BRANCH YELLOW RIVER

096061604, Allamakee, IA

Built 1962 Load: 26.8 t ADT: 29

LOCAL

Fair

Over: CREEK

078341602, Audubon, IA

Built 1977 Load: 26.8 t ADT: 51

LOCAL

Fair

Over: STREAM

083111901, Benton, IA

Built 2002 Load: 26.8 t ADT: 11

MAIN RD

Fair

Over: TRIB TO ROCK CREEK

87-11-32-05-10, Black Hawk, IA

Built 1974 Load: 26.8 t ADT: 69

LOCAL

Fair

Over: LITTLE ELKHORN CREEK

079011601, Cedar, IA

Built 2001 Load: 26.8 t ADT: 20

170TH ST

Fair

Over: ROCK CR

081031101, Cedar, IA

Built 1975 Load: 26.8 t ADT: 11

FM

Fair

Over: BALDWIN CREEK

081042206, Cedar, IA

Built 1975 Load: 26.8 t ADT: 120

FINCH

Fair

Over: WATERWAY

094222402, Cerro Gordo, IA

Built 1965 Load: 26.8 t ADT: 25

LOCAL

Fair

Over: SMALL

095113102, Chickasaw, IA

Built 1978 Load: 26.8 t ADT: 16

FM

Fair

Over: OTTER CREEK BRANCH

073243303, Clarke, IA

Built 1970 Load: 26.8 t ADT: 40

105TH ST.

Fair

Over: RAT RUN CREEK

083E10403, Clinton, IA

Built 1986 Load: 26.8 t ADT: 11

O CIRCLE

Fair

Over: HICKORY CREEK

079271703, Dallas, IA

Built 1941 Load: 26.8 t ADT: 21

COUNTY ROAD

Fair

Over: BRANCH PANTHER CREEK

079282702, Dallas, IA

Built 1948 Load: 26.8 t ADT: 62

COUNTY ROAD

Fair

Over: BRANCH PANTHER CREEK

080293601, Dallas, IA

Built 1917 Load: 26.8 t ADT: 41

FM

Fair

Over: GRAND RIVER

069262007, Decatur, IA

Built 1967 Load: 26.8 t ADT: 29

LOCAL

Fair

Over: KNOTTY CREEK

071032501, Des Moines, IA

Built 1972 Load: 26.8 t ADT: 123

LOCAL

Fair

Over: CREEK

096181101, Floyd, IA

Built 1989 Load: 26.8 t ADT: 15

M AVE

Fair

Over: STREAM

082300702, Greene, IA

Built 1971 Load: 26.8 t ADT: 62

QUEST AVE/P30

Fair

Over: DEADBRIER CREEK

082303504, Greene, IA

Built 1969 Load: 26.8 t ADT: 210

310 TH

Fair

Over: STREAM

082322101, Greene, IA

Built 1966 Load: 26.8 t ADT: 21

A AVE / N58

Fair

Over: WILLOW CREEK

083323002, Greene, IA

Built 1964 Load: 26.8 t ADT: 358

US 63

Fair

Over: CRANE CREEK

0.7 mi. S of jct. SR B17, Howard, IA

Built 1971 Load: 26.8 t ADT: 4,280

FM 135TH ST

Fair

Over: DRAINAGE DITCH

098111203, Howard, IA

Built 1973 Load: 26.8 t ADT: 25

FM

Fair

Over: DD

092301102, Humboldt, IA

Built 1948 Load: 26.8 t ADT: 34

FM

Fair

Over: UNNAMED CREEK

086393501, Ida, IA

Built 1972 Load: 26.8 t ADT: 159

LOCAL

Fair

Over: SMITH CREEK

072110202, Jefferson, IA

Built 1965 Load: 26.8 t ADT: 30

LOCAL

Fair

Over: COON CREEK

073113307, Jefferson, IA

Built 1954 Load: 26.8 t ADT: 30

US 169

Fair

Over: E FORK DES MOINES RIVER

1.2 mi. S of S.R. B40, Kossuth, IA

Built 1971 Load: 26.8 t ADT: 3,460

FM 310TH ST

Fair

Over: LOTTS CREEK

097301901, Kossuth, IA

Built 1971 Load: 26.8 t ADT: 450

6TH ST

Fair

Over: OVER UP RR

000000000, Linn, IA

Built 1948 Load: 26.8 t ADT: 9,391

IA 9

Fair

Over: BLOODRUN CREEK

0.3 mi. E of Jct. SR K12, Lyon, IA

Built 1977 Load: 26.8 t ADT: 4,520

LOCAL

Fair

Over: LITTLE ROCK RIVER

098452202, Lyon, IA

Built 1987 Load: 26.8 t ADT: 26

US 169

Fair

Over: NORTH RIVER

3.5 MI. N OF N JCT. IA 92, Madison, IA

Built 1969 Load: 26.8 t ADT: 4,280

OLD IA 102

Fair

Over: BRANCH MIDDLE CREEK

077162001, Mahaska, IA

Built 1961 Load: 26.8 t ADT: 1,550

LOCAL

Fair

Over: SKUNK CREEK

084420106, Monona, IA

Built 1990 Load: 26.8 t ADT: 11

US 34

Fair

Over: COAL CREEK

2.0 MI. W OF JCT. IA 5, Monroe, IA

Built 1964 Load: 26.8 t ADT: 3,220

QUORN RD

Fair

Over: WEST FORK LITTLE SIOUX

090442504, Plymouth, IA

Built 1965 Load: 26.8 t ADT: 40

Showing 4,701-4,750 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.