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

C14

Fair

Over: CREEK

093090101, Fayette, IA

Built 1926 Load: 25.4 t ADT: 432

C14

Fair

Over: COULEE CREEK

093090201, Fayette, IA

Built 1925 Load: 25.4 t ADT: 432

205 TH

Fair

Over: STREAM

084302503, Greene, IA

Built 1937 Load: 25.4 t ADT: 51

LOCAL

Fair

Over: IA RIVER

088220304, Hardin, IA

Built 1957 Load: 25.4 t ADT: 26

IRIS AVE

Fair

Over: BEAVER CREEK

099130402, Howard, IA

Built 1952 Load: 25.4 t ADT: 30

LOCAL

Fair

Over: MILL CREEK

086E30109, Jackson, IA

Built 1959 Load: 25.4 t ADT: 5

SB I-380

Fair

Over: IOWA RIVER

7.9 MI. N OF JCT. I-80, Johnson, IA

Built 1972 Load: 25.4 t ADT: 27,200

FM

Fair

Over: STREAM

074110901, Keokuk, IA

Built 1950 Load: 25.4 t ADT: 30

LOCAL

Fair

Over: CEDAR CREEK

074142802, Mahaska, IA

Built 1900 Load: 25.4 t ADT: 5

IA 330

Fair

Over: CHICKEN CREEK

3.9 MILES W OF JCT IA 14, Marshall, IA

Built 1957 Load: 25.4 t ADT: 1,490

350TH

Fair

Over: SPRING CREEK

098163201, Mitchell, IA

Built 1973 Load: 25.4 t ADT: 33

IA 22

Fair

Over: DRAINAGE DITCH

3.5 MI. E of Jct. IA 38, Muscatine, IA

Built 1978 Load: 25.4 t ADT: 1,730

LOCAL

Fair

Over: WALNUT CREEK

081141402, Poweshiek, IA

Built 1955 Load: 25.4 t ADT: 30

LOCAL

Fair

Over: E BR KEG CREEK

078401701, Shelby, IA

Built 1957 Load: 25.4 t ADT: 26

FM

Fair

Over: DRAINAGE DITCH

067321203, Taylor, IA

Built 1940 Load: 25.4 t ADT: 79

FM

Fair

Over: INDIAN CREEK

068110104, Van Buren, IA

Built 1987 Load: 25.4 t ADT: 500

LOCAL

Fair

Over: STREAM

088463304, Woodbury, IA

Built 1985 Load: 25.4 t ADT: 50

LOCAL (LWC)

Fair

Over: PRATT CREEK

085122601, Benton, IA

Built 1995 Load: 25.5 t ADT: 11

HARDING AVE

Fair

Over: BR ROCK CREEK

081033202, Cedar, IA

Built 1997 Load: 25.5 t ADT: 20

LOCAL

Fair

Over: SOLDIER CREEK

100331202, Emmet, IA

Built 1962 Load: 25.5 t ADT: 50

300 STREET

Fair

Over: ROCK CREEK

067402301, Fremont, IA

Built 1981 Load: 25.5 t ADT: 15

LOCAL

Fair

Over: CREEK

087201106, Hardin, IA

Built 1959 Load: 25.5 t ADT: 20

LOCAL

Fair

Over: BR LITTLE TURKEY RIVER

098113002, Howard, IA

Built 1944 Load: 25.5 t ADT: 25

FM 660TH ST

Fair

Over: RICHEY CREEK

077052501, Johnson, IA

Built 1979 Load: 25.5 t ADT: 35

FM

Fair

Over: WEST RAT CREEK

098431501, Lyon, IA

Built 1977 Load: 25.5 t ADT: 259

FM

Fair

Over: PUTNAM CREEK

098443301, Lyon, IA

Built 1977 Load: 25.5 t ADT: 649

CHESTNUT ROAD

Fair

Over: FARM CREEK

074391401, Pottawattamie, IA

Built 2004 Load: 25.5 t ADT: 5

DOGWOOD ROAD

Fair

Over: MIDDLE SILVER CREEK

075413101, Pottawattamie, IA

Built 1979 Load: 25.5 t ADT: 71

FM

Fair

Over: SMALL STREAM

078132002, Poweshiek, IA

Built 1971 Load: 25.5 t ADT: 35

LOCAL ROAD

Fair

Over: TURKEY CREEK

074230402, Warren, IA

Built 1940 Load: 25.5 t ADT: 26

110TH ST

Fair

Over: STREAM

093121203, Bremer, IA

Built 1995 Load: 25.6 t ADT: 49

US 71

Fair

Over: BRANCH RACCOON RIVER

4.1 mi. S of IA 3, Buena Vista, IA

Built 1996 Load: 25.6 t ADT: 3,000

ADAMS AVE

Fair

Over: CLEAR CREEK

082043008, Cedar, IA

Built 1981 Load: 25.6 t ADT: 71

FM

Fair

Over: WEST CREEK

073250202, Clarke, IA

Built 1962 Load: 25.6 t ADT: 71

LOCAL

Fair

Over: ROYER CREEK

080260302, Dallas, IA

Built 1953 Load: 25.6 t ADT: 21

FM 220 AVE

Fair

Over: SMALL

087043002, Delaware, IA

Built 1980 Load: 25.6 t ADT: 20

LOC 275TH ST

Fair

Over: STREAM

088063303, Delaware, IA

Built 1975 Load: 25.6 t ADT: 15

FM 180TH ST

Fair

Over: SMALL STREAM

089031801, Delaware, IA

Built 1978 Load: 25.6 t ADT: 69

LOC 207TH ST

Fair

Over: STREAM

089062807, Delaware, IA

Built 1977 Load: 25.6 t ADT: 29

JET RD

Fair

Over: STREAM

090051403, Delaware, IA

Built 1969 Load: 25.6 t ADT: 44

FM

Fair

Over: TETE DES MORTS RIVER

087E40405, Jackson, IA

Built 1995 Load: 25.6 t ADT: 70

FM

Fair

Over: BIG CEDAR RIVER

071083204, Jefferson, IA

Built 1977 Load: 25.6 t ADT: 50

COUNTY RD X-40

Fair

Over: WHITE OAK CREEK

083031902, Jones, IA

Built 1960 Load: 25.6 t ADT: 770

FM

Fair

Over: LITTLE ROCK RIVER

098451404, Lyon, IA

Built 1955 Load: 25.6 t ADT: 369

FM

Fair

Over: LITTLE ROCK RIVER

098453101, Lyon, IA

Built 1954 Load: 25.6 t ADT: 709

LOCAL RD

Fair

Over: DRAINAGE

076280405, Madison, IA

Built 1999 Load: 25.6 t ADT: 45

LOCAL

Fair

Over: MOON CREEK

077140705, Mahaska, IA

Built 1952 Load: 25.6 t ADT: 11

VALLEY AVE

Fair

Over: CREEK

097150302, Mitchell, IA

Built 1971 Load: 25.6 t ADT: 33

LOCAL

Fair

Over: HEISLER CREEK

085421802, Monona, IA

Built 1976 Load: 25.6 t ADT: 11

FM

Fair

Over: SPRING CREEK

078223003, Polk, IA

Built 1968 Load: 25.6 t ADT: 1,215

Showing 4,301-4,350 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.