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 240TH ST

Fair

Over: E FORK DES MOINES RIVER

096292501, Kossuth, IA

Built 1977 Load: 21.6 t ADT: 62

LOCAL

Fair

Over: N SKUNK RIVER

076141505, Mahaska, IA

Built 1975 Load: 21.6 t ADT: 26

LOCAL

Fair

Over: N SKUNK RIVER

077151703, Mahaska, IA

Built 1977 Load: 21.6 t ADT: 71

FM

Fair

Over: SKUNK RIVER

077182304, Marion, IA

Built 1954 Load: 21.6 t ADT: 220

FM

Fair

Over: CALHOUN CREEK

077201603, Marion, IA

Built 1969 Load: 21.6 t ADT: 110

LOCAL

Fair

Over: WALNUT CREEK

077210203, Marion, IA

Built 1969 Load: 21.6 t ADT: 73

NB US 75

Fair

Over: DRAINAGE DITCH

3.0 mi. N of Jct. SR C60, Plymouth, IA

Built 1972 Load: 21.6 t ADT: 7,000

IA 3

Fair

Over: NORTH LIZARD CREEK

0.8 mi. W of IA 15, Pocahontas, IA

Built 1987 Load: 21.6 t ADT: 2,390

215TH STREET

Fair

Over: STREAM

077433406, Pottawattamie, IA

Built 1995 Load: 21.6 t ADT: 26

EB US 30

Fair

Over: SOUTH SKUNK RIVER

1.2 MI. W OF JCT. I-35, Story, IA

Built 1963 Load: 21.6 t ADT: 15,600

LOCAL

Fair

Over: MIDDLE RIVER

077232204, Warren, IA

Built 1971 Load: 21.6 t ADT: 180

FM

Fair

Over: TURKEY RIVER BRANCH

097100106, Winneshiek, IA

Built 1962 Load: 21.6 t ADT: 658

IA 3

Fair

Over: STREAM

2.7 MI. E OF E Jct US 69, Wright, IA

Built 1976 Load: 21.6 t ADT: 1,620

E REINBECK RD

Fair

Over: MILLER CREEK

87-13-26-01-10, Black Hawk, IA

Built 1948 Load: 21.7 t ADT: 5

N PILOT GROVE RD

Fair

Over: CRANE CREEK

90-11-29-02-10, Black Hawk, IA

Built 1948 Load: 21.7 t ADT: 59

E BENNINGTON RD

Fair

Over: CRANE CREEK

90-12-23-01-10, Black Hawk, IA

Built 1948 Load: 21.7 t ADT: 29

KILLDEER

Fair

Over: WINNEBAGO RIVER

097211404, Cerro Gordo, IA

Built 1984 Load: 21.7 t ADT: 432

FM 590TH ST.

Fair

Over: WILLOW CREEK

091413101, Cherokee, IA

Built 1964 Load: 21.7 t ADT: 26

140TH AVE

Fair

Over: OCHEYEDAN RIVER

096381102, Clay, IA

Built 1963 Load: 21.7 t ADT: 153

LOC 285 ST

Fair

Over: SMALL STREAM

087030509, Delaware, IA

Built 1966 Load: 21.7 t ADT: 29

LOCAL 210 AVE

Fair

Over: SMALL STREAM

087052502, Delaware, IA

Built 1965 Load: 21.7 t ADT: 11

FM 182ND ST

Fair

Over: SMALL STREAM

089031503, Delaware, IA

Built 1991 Load: 21.7 t ADT: 59

LOCAL 120 ST

Fair

Over: SMALL STREAM

090061301, Delaware, IA

Built 1971 Load: 21.7 t ADT: 88

LOCAL

Fair

Over: SMALL STREAM

087012408, Dubuque, IA

Built 1900 Load: 21.7 t ADT: 40

LOCAL

Fair

Over: LITTLE MAQUOKETA RIVER

090E13604, Dubuque, IA

Built 1978 Load: 21.7 t ADT: 80

LOCAL 30TH ST

Fair

Over: BEAVER CREEK

090193401, Franklin, IA

Built 1973 Load: 21.7 t ADT: 44

BRENTWOOD

Fair

Over: WILLOW CREEK

082322904, Greene, IA

Built 1980 Load: 21.7 t ADT: 26

IA 17

Fair

Over: IOWAY CREEK

0.9 MILE S OF JCT SR D65, Hamilton, IA

Built 1979 Load: 21.7 t ADT: 2,260

LOCAL

Fair

Over: DD

091271504, Humboldt, IA

Built 1937 Load: 21.7 t ADT: 15

35TH ST.

Fair

Over: SO FORK WALNUT

083041903, Jones, IA

Built 1990 Load: 21.7 t ADT: 33

OLD CASS RD.

Fair

Over: HELMER CREEK

085041801, Jones, IA

Built 1983 Load: 21.7 t ADT: 73

FREEMONT RD.

Fair

Over: HELMER CREEK

085042004, Jones, IA

Built 1976 Load: 21.7 t ADT: 88

158TH ST.

Fair

Over: SAMS CREEK

085042203, Jones, IA

Built 1986 Load: 21.7 t ADT: 79

JONES-DELAWARE

Fair

Over: GROVE CREEK

086040401, Jones, IA

Built 1985 Load: 21.7 t ADT: 33

230TH ST.

Fair

Over: SILVER CREEK

086041501, Jones, IA

Built 1971 Load: 21.7 t ADT: 20

LOCAL

Fair

Over: SUGAR CREEK

067063303, Lee, IA

Built 1985 Load: 21.7 t ADT: 120

LOCAL

Fair

Over: SUGAR CREEK

068062403, Lee, IA

Built 1974 Load: 21.7 t ADT: 50

RED HAW RD

Fair

Over: BIG CR

083061404, Linn, IA

Built 1959 Load: 21.7 t ADT: 69

LCL-RAINS AVE

Fair

Over: DEER CREEK

071413601, Mills, IA

Built 1999 Load: 21.7 t ADT: 5

LOCAL SEC RD

Fair

Over: WILLOW CR

094401102, O'Brien, IA

Built 2001 Load: 21.7 t ADT: 41

LOCAL

Fair

Over: STREAM

099413302, Osceola, IA

Built 1944 Load: 21.7 t ADT: 21

LOCAL ROAD

Fair

Over: SMALL STREAM

075072304, Washington, IA

Built 1950 Load: 21.7 t ADT: 60

LOCAL ROAD

Fair

Over: CREEK

098081204, Winneshiek, IA

Built 1900 Load: 21.7 t ADT: 29

MC STAY RD

Fair

Over: TRIB TO INDIAN CREEK

88-11-19-01-10, Black Hawk, IA

Built 1950 Load: 21.8 t ADT: 11

WB US 30

Fair

Over: SILVER CK & UP RR

0.7 MI. E OF W JCT. US 61, Clinton, IA

Built 1970 Load: 21.8 t ADT: 8,550

FM

Fair

Over: SMALL STREAM

085382805, Crawford, IA

Built 1941 Load: 21.8 t ADT: 50

110 TH

Fair

Over: STREAM

085301101, Greene, IA

Built 1934 Load: 21.8 t ADT: 11

FM

Fair

Over: ROCK CREEK

074111010, Keokuk, IA

Built 1968 Load: 21.8 t ADT: 200

LEVEE

Fair

Over: LAKE ODESSA OUTLET

SEC 36 T74N R2W, Louisa, IA

Built 1996 Load: 21.8 t ADT: 1

LOCAL

Fair

Over: STREAM

074211504, Marion, IA

Built 1994 Load: 21.8 t ADT: 16

Showing 3,051-3,100 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.