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

150TH ST

Good

Over: SMALL STREAM

090073103, Buchanan, IA

Built 2018 Load: 30.4 t ADT: 60

OVERLAND AVE

Good

Over: SMALL STREAM

0870821, Buchanan, IA

Built 2020 Load: 30.4 t ADT: 20

LOCAL

Good

Over: DD NO 1

089332902, Calhoun, IA

Built 1974 Load: 30.4 t ADT: 15

FM

Good

Over: MIDDLE RACCOON RIVER

082332704, Carroll, IA

Built 1968 Load: 30.4 t ADT: 737

140TH AVE

Good

Over: STONY CREEK

097381102, Clay, IA

Built 1978 Load: 30.4 t ADT: 46

FM

Good

Over: TRINKLE CREEK

085371702, Crawford, IA

Built 1977 Load: 30.4 t ADT: 219

ROSE RD

Good

Over: LITTLE TURKEY RIVER

095092906, Fayette, IA

Built 1976 Load: 30.4 t ADT: 432

LOCAL

Good

Over: ACKLEY CREEK

094171902, Floyd, IA

Built 1985 Load: 30.4 t ADT: 20

255 TH

Good

Over: HARDIN CREEK

083302203, Greene, IA

Built 1981 Load: 30.4 t ADT: 35

FM-TOLEDO AVE

Good

Over: EAST PICAYUNE CREEK

080410304, Harrison, IA

Built 1977 Load: 30.4 t ADT: 60

FM/CANTON AVE

Good

Over: SOLDIER RIVER

080451402, Harrison, IA

Built 1974 Load: 30.4 t ADT: 29

LOCAL

Good

Over: OTTER CREEK

073030401, Louisa, IA

Built 1978 Load: 30.4 t ADT: 91

FM

Good

Over: SMALL

093461201, Plymouth, IA

Built 1978 Load: 30.4 t ADT: 450

FM

Good

Over: DRAINAGE

074383604, Pottawattamie, IA

Built 1963 Load: 30.4 t ADT: 34

FM

Good

Over: SILVER CREEK

074412804, Pottawattamie, IA

Built 1975 Load: 30.4 t ADT: 50

IA 2

Good

Over: W FORK OF GRAND RIVER

0.8 MI. W OF Jct. SR P33, Ringgold, IA

Built 1976 Load: 30.4 t ADT: 1,180

K64

Good

Over: FLOYD RIVER

094443302, Sioux, IA

Built 1975 Load: 30.4 t ADT: 995

FM

Good

Over: W BRANCH FLOYD RIVER

094453201, Sioux, IA

Built 1977 Load: 30.4 t ADT: 71

US 151

Good

Over: KNAPP CREEK

1.3 mi. N of SR E66, Benton, IA

Built 1995 Load: 30.5 t ADT: 7,800

IA 346

Good

Over: LITTLE CEDAR CREEK

0.1 mi. W of Jct. SR T76, Chickasaw, IA

Built 1991 Load: 30.5 t ADT: 2,460

308TH AVE

Good

Over: AMES CREEK

081E40906, Clinton, IA

Built 1979 Load: 30.5 t ADT: 70

220TH AVE

Good

Over: DEEP CREEK

082E30602, Clinton, IA

Built 2013 Load: 30.5 t ADT: 35

240TH AVE

Good

Over: NO NAME CREEK

082E32802, Clinton, IA

Built 1970 Load: 30.5 t ADT: 30

250TH ST

Good

Over: N WYACONDAH CREEK

068131601, Davis, IA

Built 2011 Load: 30.5 t ADT: 80

LOCAL 145 ST

Good

Over: SMALL STREAM

090032603, Delaware, IA

Built 1990 Load: 30.5 t ADT: 88

C50 (40TH ST)

Good

Over: UNNAMED CREEK

091102001, Fayette, IA

Built 2012 Load: 30.5 t ADT: 108

COUNTY RD E-34

Good

Over: WAPSIPINICON RIVER

084041004, Jones, IA

Built 1994 Load: 30.5 t ADT: 3,896

KENNEDY ST

Good

Over: COMPETINE CREEK

076193401, Marion, IA

Built 2021 Load: 30.5 t ADT: 160

US 59

Good

Over: MILL CREEK

0.4 mi. N of Jct. SR B24, O'Brien, IA

Built 1973 Load: 30.5 t ADT: 980

FM

Good

Over: WILLOW CREEK

95 42 30 02, O'Brien, IA

Built 2010 Load: 30.5 t ADT: 478

FM K-13

Good

Over: WESTFIELD CREEK

092482902, Plymouth, IA

Built 1988 Load: 30.5 t ADT: 180

FM

Good

Over: W BRANCH FLOYD RIVER

093450803, Plymouth, IA

Built 1976 Load: 30.5 t ADT: 658

FM

Good

Over: RICHLAND CREEK

082162201, Tama, IA

Built 2007 Load: 30.5 t ADT: 29

LOCAL

Good

Over: RICHLAND CREEK

082162402, Tama, IA

Built 2008 Load: 30.5 t ADT: 26

LOCAL

Good

Over: EAST BRANCH SALT CREEK

084132305, Tama, IA

Built 2003 Load: 30.5 t ADT: 5

LOCAL

Good

Over: EAST BRANCH SALT CREEK

084132404, Tama, IA

Built 2002 Load: 30.5 t ADT: 33

US 20

Good

Over: DRAINAGE DITCH #4

At Jct. SR P73, Webster, IA

Built 1986 Load: 30.5 t ADT: 9,500

NORTH WINN RD

Good

Over: CANOE CREEK

099080904, Winneshiek, IA

Built 1959 Load: 30.5 t ADT: 570

FM

Good

Over: S. BEAR CREEK

100073404, Winneshiek, IA

Built 1975 Load: 30.5 t ADT: 236

FM

Good

Over: ROCK RUN CREEK

081030805, Cedar, IA

Built 2008 Load: 30.6 t ADT: 30

LOCAL 560TH ST

Good

Over: WEST FORK LITTLE SIOUX

091421501, Cherokee, IA

Built 1985 Load: 30.6 t ADT: 26

FM

Good

Over: BEAVER CREEK

081281105, Dallas, IA

Built 1979 Load: 30.6 t ADT: 210

LOCAL

Good

Over: SMALL STREAM

094160601, Floyd, IA

Built 1987 Load: 30.6 t ADT: 39

260TH ST

Good

Over: TRIB. TO TROUBLESOME

079332901, Guthrie, IA

Built 2012 Load: 30.6 t ADT: 11

WB US 34

Good

Over: KEG CREEK

0.2 mi. E of jct. SR L35, Mills, IA

Built 1969 Load: 30.6 t ADT: 3,650

IA 175

Good

Over: DRAINAGE DITCH

0.7 mi. W of jct. SR E34, Monona, IA

Built 1973 Load: 30.6 t ADT: 1,140

LOCAL

Good

Over: LITTLE FLOYD RIVER

096421001, O'Brien, IA

Built 1975 Load: 30.6 t ADT: 46

LOCAL

Good

Over: SO BR LITTLE FLOYD RIVER

096421201, O'Brien, IA

Built 1975 Load: 30.6 t ADT: 35

FM C-60

Good

Over: KETTLE CREEK

090461101, Plymouth, IA

Built 1969 Load: 30.6 t ADT: 628

FM

Good

Over: BROKEN KETTLE CREEK

090480305, Plymouth, IA

Built 1976 Load: 30.6 t ADT: 489

Showing 10,151-10,200 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.