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

YATES AVE

Fair

Over: SMALL STREAM

078413602, Harrison, IA

Built 1960 Load: 15.0 t ADT: 20

LOCAL

Fair

Over: WILDCAT CREEK

076211202, Marion, IA

Built 1971 Load: 15.0 t ADT: 73

FM

Fair

Over: RAT CREEK

098420802, Osceola, IA

Built 1935 Load: 15.0 t ADT: 20

FILBERT AVENUE

Fair

Over: WILLIAMS CREEK

073340604, Adams, IA

Built 1972 Load: 15.1 t ADT: 45

LOCAL

Fair

Over: DRAINAGE DITCH

092372502, Buena Vista, IA

Built 1975 Load: 15.1 t ADT: 60

LOCAL

Fair

Over: CAMP CREEK

087340501, Calhoun, IA

Built 1990 Load: 15.1 t ADT: 20

FINCH

Fair

Over: BEAVER DAM CREEK

095220206, Cerro Gordo, IA

Built 1962 Load: 15.1 t ADT: 15

LOCAL

Fair

Over: SIMPSON CREEK

095112502, Chickasaw, IA

Built 1951 Load: 15.1 t ADT: 30

FM

Fair

Over: SOUTH WHITE BREAST CREEK

071241002, Clarke, IA

Built 1939 Load: 15.1 t ADT: 45

LOCAL

Fair

Over: BR N RACCOON

079272103, Dallas, IA

Built 1935 Load: 15.1 t ADT: 113

LOCAL

Fair

Over: JONATHAN CREEK

070252604, Decatur, IA

Built 1996 Load: 15.1 t ADT: 15

LOCAL

Fair

Over: BLACK CAT CREEK

098312502, Emmet, IA

Built 1954 Load: 15.1 t ADT: 15

180TH ST

Fair

Over: SMALL STREAM

097140601, Howard, IA

Built 1986 Load: 15.1 t ADT: 21

LOC 60TH AVE

Fair

Over: MUD CREEK

099302402, Kossuth, IA

Built 1967 Load: 15.1 t ADT: 26

LOC 20TH AVE

Fair

Over: SOUTH CREEK

100301702, Kossuth, IA

Built 1965 Load: 15.1 t ADT: 112

LOCAL

Fair

Over: RAT CREEK

098420801, Osceola, IA

Built 1957 Load: 15.1 t ADT: 15

300TH ST

Fair

Over: DEER CREEK

090431701, Plymouth, IA

Built 1990 Load: 15.1 t ADT: 30

LOCAL

Fair

Over: LONG BRANCH

081372603, Shelby, IA

Built 1987 Load: 15.1 t ADT: 41

720TH AVE

Fair

Over: WILLOW CREEK

082210202, Story, IA

Built 1945 Load: 15.1 t ADT: 15

LOCAL

Fair

Over: DRAINAGE

093181801, Butler, IA

Built 1967 Load: 15.2 t ADT: 20

LOCAL

Fair

Over: OTTER CREEK

073241504, Clarke, IA

Built 1942 Load: 15.2 t ADT: 34

COFFEE RD

Fair

Over: PLUM CREEK

091013403, Clayton, IA

Built 1900 Load: 15.2 t ADT: 49

JASMINE RD

Fair

Over: CEDAR CREEK

092030603, Clayton, IA

Built 1953 Load: 15.2 t ADT: 15

KENNEDY RD

Fair

Over: CEDAR CREEK

092030703, Clayton, IA

Built 1955 Load: 15.2 t ADT: 34

KENNEDY RD

Fair

Over: STREAM

092030703, Clayton, IA

Built 1955 Load: 15.2 t ADT: 34

LOC 270 AVE

Fair

Over: PENNS CREEK

088041204, Delaware, IA

Built 1983 Load: 15.2 t ADT: 49

LOCAL

Fair

Over: SMALL CREEK

084E43605, Jackson, IA

Built 1957 Load: 15.2 t ADT: 90

200TH ST

Fair

Over: BROKEN KETTLE CREEK

092482501, Plymouth, IA

Built 1972 Load: 15.2 t ADT: 20

US 69

Fair

Over: FOURMILE CREEK

0.2 MI. S OF SR F22, Polk, IA

Built 1922 Load: 15.2 t ADT: 6,800

FM

Fair

Over: DRAINAGE DITCH

080220301, Polk, IA

Built 1959 Load: 15.2 t ADT: 45

LOCAL ROAD

Fair

Over: SMALL STREAM

086380101, Sac, IA

Built 1919 Load: 15.2 t ADT: 26

LOCAL

Fair

Over: ELK CREEK

081371801, Shelby, IA

Built 1960 Load: 15.2 t ADT: 26

FM

Fair

Over: SOUTH RIVER

075240204, Warren, IA

Built 1950 Load: 15.2 t ADT: 280

FINCHFORD RD

Fair

Over: WEST FORK CEDAR RIVER

90-14-06-08, Black Hawk, IA

Built 1959 Load: 15.3 t ADT: 373

FM 250TH ST

Fair

Over: SMALL STREAM

088072301, Buchanan, IA

Built 1957 Load: 15.3 t ADT: 100

FM STEWART AV

Fair

Over: SMITH CREEK

088073004, Buchanan, IA

Built 1958 Load: 15.3 t ADT: 39

FM 140TH ST

Fair

Over: SMALL STREAM

090092601, Buchanan, IA

Built 1958 Load: 15.3 t ADT: 80

COLD SPR ST PK

Fair

Over: STREAM

1.9 mi. S of US 6 on M-56, Cass, IA

Built 1900 Load: 15.3 t

LOCAL

Fair

Over: CREEK

100342802, Emmet, IA

Built 1914 Load: 15.3 t ADT: 45

FM

Fair

Over: BEAR CREEK

086190202, Hardin, IA

Built 1985 Load: 15.3 t ADT: 15

LOCAL(LWC)

Fair

Over: MIDDLE FORK ENGLISH RVR

078122402, Iowa, IA

Built 1992 Load: 15.3 t ADT: 15

NW 146 AVE

Fair

Over: TURKEY CREEK

0.2 MI. E OF OLD IA 415, Polk, IA

Built 1937 Load: 15.3 t ADT: 71

350TH

Fair

Over: DRAINAGE DITCH

098213401, Worth, IA

Built 1915 Load: 15.3 t ADT: 10

495TH

Fair

Over: SHELLROCK RIVER

100201807, Worth, IA

Built 1955 Load: 15.3 t ADT: 104

LOCAL

Fair

Over: ELK RUN

085341107, Carroll, IA

Built 1900 Load: 15.4 t ADT: 34

LOCAL

Fair

Over: EAST LONG CREEK

071271404, Clarke, IA

Built 1977 Load: 15.4 t ADT: 11

140 TH

Fair

Over: DRAINAGE DITCH

085302901, Greene, IA

Built 1935 Load: 15.4 t ADT: 15

KILLDEER AVE

Fair

Over: NORTH SKUNK RIVER

079170801, Jasper, IA

Built 1964 Load: 15.4 t ADT: 82

FM

Fair

Over: DEER CREEK

074271904, Madison, IA

Built 1951 Load: 15.4 t ADT: 50

BUNGE AVE

Fair

Over: MISSOURI RIVER (TOLL)

Nebraska State Line, Mills, IA

Built 1952 Load: 15.4 t ADT: 2,174

Showing 1,451-1,500 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.