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

LOC 110TH AVE

Fair

Over: MUD CREEK

098291102, Kossuth, IA

Built 1983 Load: 21.2 t ADT: 26

LOC 350TH ST

Fair

Over: MUD CREEK

098293603, Kossuth, IA

Built 1978 Load: 21.2 t ADT: 112

LOC 210TH AVE

Fair

Over: DRAINAGE DITCH #90

099273302, Kossuth, IA

Built 1983 Load: 21.2 t ADT: 35

LOC 480TH ST

Fair

Over: MIDDLE BRANCH BLUE EARTH

100273001, Kossuth, IA

Built 1976 Load: 21.2 t ADT: 21

LOC 470TH ST

Fair

Over: MIDDLE BRANCH BLUE EARTH

100273101, Kossuth, IA

Built 1976 Load: 21.2 t ADT: 30

LOCAL

Fair

Over: JACK CREEK

066050501, Lee, IA

Built 1928 Load: 21.2 t ADT: 11

LOCAL

Fair

Over: STREAM

067050501, Lee, IA

Built 1974 Load: 21.2 t ADT: 131

LOCAL

Fair

Over: FIVE MILE CREEK

071223301, Lucas, IA

Built 1977 Load: 21.2 t ADT: 16

FM

Fair

Over: FIVE MILE CREEK

071223402, Lucas, IA

Built 1977 Load: 21.2 t ADT: 80

LOCAL

Fair

Over: STONY CREEK

073220301, Lucas, IA

Built 1975 Load: 21.2 t ADT: 15

LOCAL

Fair

Over: NORTH CLANTON CREEK

074280605, Madison, IA

Built 1988 Load: 21.2 t ADT: 20

FM

Fair

Over: STREAM

071180605, Monroe, IA

Built 1968 Load: 21.2 t ADT: 30

LOCAL

Fair

Over: COAL CREEK

072172903, Monroe, IA

Built 1983 Load: 21.2 t ADT: 120

110TH STREET

Fair

Over: EAST TARKIO RIVER

070371001, Page, IA

Built 1977 Load: 21.2 t ADT: 60

FM

Fair

Over: BULL RUN CREEK

092483601, Plymouth, IA

Built 1960 Load: 21.2 t ADT: 838

LOCAL

Fair

Over: BEAR CREEK

081162604, Poweshiek, IA

Built 1970 Load: 21.2 t ADT: 50

FM

Fair

Over: SAND CREEK

070280304, Ringgold, IA

Built 1986 Load: 21.2 t ADT: 50

FM

Fair

Over: SMALL STREAM

086373303, Sac, IA

Built 1984 Load: 21.2 t ADT: 60

LOCAL

Fair

Over: CREEK

079E20902, Scott, IA

Built 1965 Load: 21.2 t ADT: 150

264TH ST.

Fair

Over: CREEK

080E53203, Scott, IA

Built 1962 Load: 21.2 t ADT: 90

LOCAL

Fair

Over: OTTER CR

097430702, Sioux, IA

Built 1963 Load: 21.2 t ADT: 11

FM

Fair

Over: OTTER CREEK

097430801, Sioux, IA

Built 1962 Load: 21.2 t ADT: 619

LOCAL

Fair

Over: OTTER CREEK

097430802, Sioux, IA

Built 1962 Load: 21.2 t ADT: 45

FM

Fair

Over: OTTER CREEK

097441201, Sioux, IA

Built 1962 Load: 21.2 t ADT: 619

FM

Fair

Over: BRANCH WOLF CREEK

085150301, Tama, IA

Built 1968 Load: 21.2 t ADT: 15

LOCAL

Fair

Over: SMALL

069342401, Taylor, IA

Built 1980 Load: 21.2 t ADT: 26

LOCAL

Fair

Over: CREEK

070340302, Taylor, IA

Built 1950 Load: 21.2 t ADT: 20

LOCAL

Fair

Over: SHORT CREEK

076232204, Warren, IA

Built 1949 Load: 21.2 t ADT: 134

FM

Fair

Over: BR SOUTH RIVER

077223306, Warren, IA

Built 1940 Load: 21.2 t ADT: 71

LOCAL

Fair

Over: WHITE FOX CREEK

090252402, Wright, IA

Built 1983 Load: 21.2 t ADT: 21

LOCAL

Fair

Over: DRAINAGE DITCH 36

091251703, Wright, IA

Built 1982 Load: 21.2 t ADT: 41

LOCAL

Fair

Over: OTTER CREEK

092262104, Wright, IA

Built 1982 Load: 21.2 t ADT: 36

LOCAL

Fair

Over: EAGLE CREEK(DD#36)

093253402, Wright, IA

Built 1984 Load: 21.2 t ADT: 31

KEYSTONE AVE.

Fair

Over: STREAM

093172602, Butler, IA

Built 2011 Load: 21.3 t ADT: 39

LOCAL

Fair

Over: CREEK

097173401, Floyd, IA

Built 1900 Load: 21.3 t ADT: 39

HOLLY AVE

Fair

Over: MEAD CREEK

098133204, Howard, IA

Built 1958 Load: 21.3 t ADT: 82

FM

Fair

Over: BUFFALO CREEK

088393101, Ida, IA

Built 1980 Load: 21.3 t ADT: 20

LOCAL

Fair

Over: CREEK

076111701, Keokuk, IA

Built 1947 Load: 21.3 t ADT: 30

LOCAL

Fair

Over: STREAM

077180702, Marion, IA

Built 1977 Load: 21.3 t ADT: 5

OLD IA 105

Fair

Over: TURTLE CREEK

099182306, Mitchell, IA

Built 1930 Load: 21.3 t ADT: 746

LOCAL

Fair

Over: TARKIO CREEK

072372301, Montgomery, IA

Built 1958 Load: 21.3 t ADT: 15

LOCAL RD

Fair

Over: LITTLE TARKIO CREEK

072382401, Montgomery, IA

Built 1957 Load: 21.3 t ADT: 34

255TH STREET

Fair

Over: WEST MILL CREEK

068372903, Page, IA

Built 1957 Load: 21.3 t ADT: 15

160TH STREET

Fair

Over: STREAM

069370803, Page, IA

Built 1961 Load: 21.3 t ADT: 26

170TH STREET

Fair

Over: NEELY BRANCH

069371203, Page, IA

Built 1957 Load: 21.3 t ADT: 45

IA 92

Fair

Over: WALNUT CREEK

0.9 MI. E OF SR M-47, Pottawattamie, IA

Built 1938 Load: 21.3 t ADT: 1,180

LOCAL

Fair

Over: LOTTS CREEK

067292303, Ringgold, IA

Built 1990 Load: 21.3 t ADT: 15

LOCAL

Fair

Over: INDIAN CREEK

071290702, Union, IA

Built 1999 Load: 21.3 t ADT: 11

FM

Fair

Over: SOUTH WOLF CREEK

074221901, Warren, IA

Built 1949 Load: 21.3 t ADT: 89

FM

Fair

Over: TURKEY RIVER

096091601, Winneshiek, IA

Built 1957 Load: 21.3 t ADT: 491

Showing 2,951-3,000 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.