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

LOCAL LINN-DEL

Fair

Over: STREAM

087053101, Delaware, IA

Built 1975 Load: 22.7 t ADT: 59

LOCAL 137 ST

Fair

Over: SMALL STREAM

090042205, Delaware, IA

Built 1939 Load: 22.7 t ADT: 44

LOCAL

Fair

Over: SMALL

087022503, Dubuque, IA

Built 1979 Load: 22.7 t ADT: 50

FM

Fair

Over: SMALL

088E10105, Dubuque, IA

Built 1980 Load: 22.7 t ADT: 71

FM

Fair

Over: HEWITT CREEK

089021303, Dubuque, IA

Built 1983 Load: 22.7 t ADT: 226

FM

Fair

Over: HEWITT CREEK

089021303, Dubuque, IA

Built 1983 Load: 22.7 t ADT: 226

FM

Fair

Over: SMALL

089021403, Dubuque, IA

Built 1983 Load: 22.7 t ADT: 216

LOCAL

Fair

Over: CREEK

090E11507, Dubuque, IA

Built 1957 Load: 22.7 t ADT: 160

FM

Fair

Over: CREEK

090E13104, Dubuque, IA

Built 1960 Load: 22.7 t ADT: 190

FM

Fair

Over: LITTLE MAQUOKETA RIVER

090E23103, Dubuque, IA

Built 1983 Load: 22.7 t ADT: 890

LOCAL

Fair

Over: CREEK

090021107, Dubuque, IA

Built 1993 Load: 22.7 t ADT: 140

RUPP HALLLOW RD

Fair

Over: ROADSIDE DITCH

00000, Dubuque, IA

Built 1980 Load: 22.7 t ADT: 49

LOCAL

Fair

Over: BLACK CAT CREEK

098310402, Emmet, IA

Built 1955 Load: 22.7 t ADT: 20

IA 150

Fair

Over: ALEXANDER CREEK

1.1 MI. N OF JCT. IA 187, Fayette, IA

Built 1959 Load: 22.7 t ADT: 2,660

IA 187

Fair

Over: BRUCE CREEK

1.2 MI. S OF JCT. IA 3, Fayette, IA

Built 1955 Load: 22.7 t ADT: 1,560

6TH AVE SW

Fair

Over: DRY RUN CREEK

000000000, Fayette, IA

Built 1976 Load: 22.7 t ADT: 1,009

200TH STREET

Fair

Over: SMALL STREAM

092220101, Franklin, IA

Built 1966 Load: 22.7 t ADT: 10

IA 2

Fair

Over: W NISHNABOTNA RIVER OVFL

1.1 MI. E OF E JCT US 275, Fremont, IA

Built 1953 Load: 22.7 t ADT: 2,050

S75 B AVE

Fair

Over: BRANCH OF BEAR CREEK

087181902, Grundy, IA

Built 1966 Load: 22.7 t ADT: 442

US 69

Fair

Over: DRAINAGE DITCH

2.2 mi. S of S jct. US 18, Hancock, IA

Built 1930 Load: 22.7 t ADT: 2,450

FM 190TH ST.

Fair

Over: DRAINAGE DITCH

097111101, Howard, IA

Built 1976 Load: 22.7 t ADT: 79

135TH ST

Fair

Over: DRAINAGE DITCH

098110903, Howard, IA

Built 1973 Load: 22.7 t ADT: 62

FM-130TH ST

Fair

Over: DRAINAGE DITCH

098121101, Howard, IA

Built 1974 Load: 22.7 t ADT: 49

LOC 115TH ST

Fair

Over: BRANCH TURKEY RIVER

099123103, Howard, IA

Built 1978 Load: 22.7 t ADT: 25

FM DOUGLAS

Fair

Over: LITTLE WAPSIPINICAN RVR

099143406, Howard, IA

Built 1950 Load: 22.7 t ADT: 88

FM 25TH ST

Fair

Over: UPPER IOWA

100121403, Howard, IA

Built 1950 Load: 22.7 t ADT: 39

FM

Fair

Over: WAPSIPINICON RIVER

098141804, Howard, IA

Built 1966 Load: 22.7 t ADT: 884

FM

Fair

Over: DM RIVER

092300705, Humboldt, IA

Built 1958 Load: 22.7 t ADT: 679

LOCAL

Fair

Over: SMALL STREAM

080091802, Iowa, IA

Built 1974 Load: 22.7 t ADT: 40

FM

Fair

Over: SMALL CREEK

084E32205, Jackson, IA

Built 1953 Load: 22.7 t ADT: 177

FM

Fair

Over: CREEK

085E41004, Jackson, IA

Built 1971 Load: 22.7 t ADT: 500

E 124TH ST S

Fair

Over: SMALL STREAM

079173302, Jasper, IA

Built 1976 Load: 22.7 t ADT: 910

FM

Fair

Over: SMALL STREAM

080212001, Jasper, IA

Built 1972 Load: 22.7 t ADT: 450

CO RD X64

Fair

Over: WAPSIPINICON RIVER

083012810, Jones, IA

Built 1949 Load: 22.7 t ADT: 393

35TH ST.

Fair

Over: SOUTH FORK WALNUT CREEK

083041905, Jones, IA

Built 1979 Load: 22.7 t ADT: 33

BUNKER HILL RD.

Fair

Over: BEERS CREEK TRIBUTARY

084011403, Jones, IA

Built 1956 Load: 22.7 t ADT: 11

140TH AVE.

Fair

Over: MINERAL CREEK

085033602, Jones, IA

Built 1970 Load: 22.7 t ADT: 41

FM

Fair

Over: STREAM

076101502, Keokuk, IA

Built 1948 Load: 22.7 t ADT: 30

BLAIRSFERRY RD

Fair

Over: TRIB TO CEDAR RIVER

000000000, Linn, IA

Built 1968 Load: 22.7 t ADT: 9,300

50TH AVE SOUTHWEST

Fair

Over: DRAINAGE DITCH

087070905, Linn, IA

Built 1960 Load: 22.7 t ADT: 1,949

FM

Fair

Over: SHORT CREEK

075050502, Louisa, IA

Built 1970 Load: 22.7 t ADT: 30

LOCAL

Fair

Over: SMALL STREAM

076051906, Louisa, IA

Built 1973 Load: 22.7 t ADT: 26

LOCAL

Fair

Over: SMALL STREAM

075043005, Louisa, IA

Built 1982 Load: 22.7 t ADT: 123

LOCAL

Fair

Over: HONEY CREEK

071201002, Lucas, IA

Built 1975 Load: 22.7 t ADT: 41

LOCAL

Fair

Over: HONEY CREEK

071222508, Lucas, IA

Built 1974 Load: 22.7 t ADT: 35

FM

Fair

Over: HAMILTON CREEK

071232201, Lucas, IA

Built 1978 Load: 22.7 t ADT: 35

LOCAL

Fair

Over: BR OF LITTLE WHITEBREAST

072212105, Lucas, IA

Built 1974 Load: 22.7 t ADT: 41

FM

Fair

Over: MOUSE CREEK

073232902, Lucas, IA

Built 1973 Load: 22.7 t ADT: 30

LOCAL

Fair

Over: STREAM

077180701, Marion, IA

Built 1977 Load: 22.7 t ADT: 35

FM

Fair

Over: SMALL

084200202, Marshall, IA

Built 1983 Load: 22.7 t ADT: 509

Showing 3,501-3,550 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.