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

FM

Fair

Over: BUCK CREEK

090102903, Buchanan, IA

Built 1965 Load: 18.8 t ADT: 88

FM

Fair

Over: NISHNABOTNA RIVER

082353303, Carroll, IA

Built 1900 Load: 18.8 t ADT: 45

PLUM AVE

Fair

Over: SUGAR CR

080022704, Cedar, IA

Built 1960 Load: 18.8 t ADT: 30

145TH ST

Fair

Over: STREAM

095052805, Clayton, IA

Built 1925 Load: 18.8 t ADT: 137

LOCAL

Fair

Over: S WYACONDAH DITCH

068140405, Davis, IA

Built 1970 Load: 18.8 t ADT: 60

LOCAL

Fair

Over: STREAM

068252908, Decatur, IA

Built 1958 Load: 18.8 t ADT: 51

NATURE RD

Fair

Over: ODELL BRANCH

090041706, Delaware, IA

Built 1939 Load: 18.8 t ADT: 59

LOCAL

Fair

Over: SOLDIER CREEK

100322602, Emmet, IA

Built 1970 Load: 18.8 t ADT: 15

IA 3 & 150

Fair

Over: OTTER CREEK

1.2 MI. E OF N JCT IA 150, Fayette, IA

Built 1955 Load: 18.8 t ADT: 2,580

70TH STREET C55

Fair

Over: FOCKLER CREEK

090191201, Franklin, IA

Built 1965 Load: 18.8 t ADT: 29

LOCAL

Fair

Over: SOUTH RACOON

080323406, Guthrie, IA

Built 1965 Load: 18.8 t ADT: 199

LOCAL

Fair

Over: CREEK

084E32503, Jackson, IA

Built 1900 Load: 18.8 t ADT: 20

FM

Fair

Over: CREEK

073091604, Jefferson, IA

Built 1965 Load: 18.8 t ADT: 15

TIMBER RD

Fair

Over: WET CREEK

086042408, Jones, IA

Built 2000 Load: 18.8 t ADT: 82

LOCAL

Fair

Over: SUGAR CREEK

066061101, Lee, IA

Built 1977 Load: 18.8 t ADT: 90

LOCAL

Fair

Over: LOST CREEK

068041004, Lee, IA

Built 1975 Load: 18.8 t ADT: 71

FM

Fair

Over: WOLF CREEK

071212201, Lucas, IA

Built 1984 Load: 18.8 t ADT: 70

S33 235TH TRL

Fair

Over: LITTLE WHITEBREAST CREEK

073213204, Lucas, IA

Built 1957 Load: 18.8 t ADT: 130

LOCAL RD

Fair

Over: NORTH RIVER

077273412, Madison, IA

Built 1966 Load: 18.8 t ADT: 29

FA-RAINS AV

Fair

Over: MCPHERRON CREEK

071423101, Mills, IA

Built 1961 Load: 18.8 t ADT: 79

FM

Fair

Over: MILLER CREEK

073162904, Monroe, IA

Built 1980 Load: 18.8 t ADT: 25

LOCAL ROAD

Fair

Over: LITTLE TARKIO CREEK

072372301, Montgomery, IA

Built 1960 Load: 18.8 t ADT: 15

LOCAL

Fair

Over: SEVEN MILE CREEK

073361704, Montgomery, IA

Built 1983 Load: 18.8 t ADT: 11

LOCAL

Fair

Over: MILL CREEK

096412602, O'Brien, IA

Built 1935 Load: 18.8 t ADT: 15

160TH STREET

Fair

Over: NEELY BRANCH

069370103, Page, IA

Built 1983 Load: 18.8 t ADT: 40

180TH STREET

Fair

Over: EAST TARKIO RIVER

069371801, Page, IA

Built 1984 Load: 18.8 t ADT: 20

180TH STREET

Fair

Over: W TARKIO RIVER

069381601, Page, IA

Built 1985 Load: 18.8 t ADT: 26

150TH STREET

Fair

Over: EAST TARKIO RIVER

070373201, Page, IA

Built 1984 Load: 18.8 t ADT: 26

130TH STREET

Fair

Over: MIDDLE TARKIO RIVER

070382401, Page, IA

Built 1984 Load: 18.8 t ADT: 11

LOCAL

Fair

Over: WEST FORK GRAND RIVER

070300305, Ringgold, IA

Built 1984 Load: 18.8 t ADT: 34

FM RD M56

Fair

Over: LONG BRANCH CREEK

80337, Shelby, IA

Built 1958 Load: 18.8 t ADT: 50

LOCAL

Fair

Over: SILVER CREEK

803439, Shelby, IA

Built 1994 Load: 18.8 t ADT: 45

FM

Fair

Over: ROCK RIVER

096470303, Sioux, IA

Built 1961 Load: 18.8 t ADT: 159

LOCAL

Fair

Over: MIDDLE BRANCH 102 RIVER

069340301, Taylor, IA

Built 1978 Load: 18.8 t ADT: 29

FM

Fair

Over: WEST BRANCH 102 RIVER

070343201, Taylor, IA

Built 1979 Load: 18.8 t ADT: 20

FM

Fair

Over: MIDDLE BRANCH 102 RIVER

070343401, Taylor, IA

Built 1979 Load: 18.8 t ADT: 29

LOCAL

Fair

Over: BEAR CREEK

072152406, Wapello, IA

Built 1970 Load: 18.8 t ADT: 40

LOCAL

Fair

Over: OTTER CREEK

075233302, Warren, IA

Built 1984 Load: 18.8 t ADT: 35

FM

Fair

Over: CEDAR CREEK

075083501, Washington, IA

Built 1962 Load: 18.8 t ADT: 120

FM

Fair

Over: DAVIS CREEK

076071101, Washington, IA

Built 1962 Load: 18.8 t ADT: 90

NUTHATCH

Fair

Over: ELK CREEK

099202904, Worth, IA

Built 1961 Load: 18.8 t ADT: 41

LOCAL

Fair

Over: BOONE RIVER

092262005, Wright, IA

Built 1979 Load: 18.8 t ADT: 31

FM

Fair

Over: GRAND RIVER

070273403, Decatur, IA

Built 1956 Load: 18.9 t ADT: 627

FM

Fair

Over: ENGLISH RIVER

079122907, Iowa, IA

Built 1952 Load: 18.9 t ADT: 70

527TH ST

Fair

Over: WHITEBREAST CREEK

073223305, Lucas, IA

Built 2016 Load: 18.9 t ADT: 62

LOCAL

Fair

Over: LITTLE OCHEYDAN RIVER

098401102, Osceola, IA

Built 1938 Load: 18.9 t ADT: 21

LOCAL

Fair

Over: STREAM

100423002, Osceola, IA

Built 1900 Load: 18.9 t ADT: 21

SB US 75

Fair

Over: DRAINAGE DITCH

3.0 mi. N of SR C60, Plymouth, IA

Built 1948 Load: 18.9 t ADT: 7,000

NB US 61

Fair

Over: WAPSIPINICON BAYOU

1.8 MI. N OF SR F33., Scott, IA

Built 1981 Load: 18.9 t ADT: 8,800

LOCAL

Fair

Over: SMALL STREAM

803440, Shelby, IA

Built 1950 Load: 18.9 t ADT: 30

Showing 2,301-2,350 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.