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

KILLDEER AVE

Poor

Over: DRAINAGE DITCH NO 6

090211102, Franklin, IA

Built 1956 Load: 25.1 t ADT: 16

FM TIMBER AVE

Poor

Over: MAYNES CREEK

091191602, Franklin, IA

Built 1955 Load: 25.1 t ADT: 49

300 210TH ST

Poor

Over: DD #10

095260901, Hancock, IA

Built 1958 Load: 25.1 t ADT: 11

FM 830 260 ST

Poor

Over: WEST IOWA RIVER

096251701, Hancock, IA

Built 1956 Load: 25.1 t ADT: 26

LOCAL

Poor

Over: DEER CREEK

078090902, Iowa, IA

Built 1976 Load: 25.1 t ADT: 71

L14

Poor

Over: DRY RUN CREEK

100442606, Lyon, IA

Built 1964 Load: 25.1 t ADT: 509

LOCAL

Poor

Over: CREEK

083171103, Marshall, IA

Built 1956 Load: 25.1 t ADT: 49

FM

Poor

Over: MINERVA CREEK

084200203, Marshall, IA

Built 1957 Load: 25.1 t ADT: 59

LOCAL

Poor

Over: INDIAN CREEK

083162902, Tama, IA

Built 1940 Load: 25.1 t ADT: 49

FM

Poor

Over: STREAM

090260901, Wright, IA

Built 1981 Load: 25.1 t ADT: 71

FM

Poor

Over: IOWA RIVER

092241405, Wright, IA

Built 1961 Load: 25.1 t ADT: 450

LOCAL ROAD

Poor

Over: BRANCH OF WOLF CREEK

086171803, Grundy, IA

Built 1977 Load: 25.2 t ADT: 44

LOCAL

Poor

Over: MINERVA CR

084201502, Marshall, IA

Built 1919 Load: 25.2 t ADT: 30

SUMAC RD

Poor

Over: STREAM

077423401, Pottawattamie, IA

Built 1949 Load: 25.2 t ADT: 45

FM

Poor

Over: STREAM

079163607, Poweshiek, IA

Built 1948 Load: 25.2 t ADT: 20

LOCAL

Poor

Over: STREAM

080161202, Poweshiek, IA

Built 1968 Load: 25.2 t ADT: 26

LOCAL

Poor

Over: SILVER CREEK

099053103, Allamakee, IA

Built 1958 Load: 25.3 t ADT: 59

FM

Poor

Over: NORTH SOAP CREEK

070161204, Appanoose, IA

Built 1968 Load: 25.3 t ADT: 850

LOCAL

Poor

Over: DAVIDS CREEK

079341704, Audubon, IA

Built 1970 Load: 25.3 t ADT: 30

LOCAL

Poor

Over: BEAVER CREEK

095181902, Floyd, IA

Built 1937 Load: 25.3 t ADT: 20

LOCAL

Poor

Over: LONG DICK CR

086230401, Hamilton, IA

Built 1924 Load: 25.3 t ADT: 20

FM

Poor

Over: DD

089210201, Hardin, IA

Built 1971 Load: 25.3 t ADT: 776

LOCAL

Poor

Over: CREEK

085E50703, Jackson, IA

Built 1940 Load: 25.3 t ADT: 11

LOCAL

Poor

Over: UNNAMED STREAM

076120201, Keokuk, IA

Built 1971 Load: 25.3 t ADT: 11

FM

Poor

Over: MOSQUITO CREEK

078022806, Muscatine, IA

Built 1978 Load: 25.3 t ADT: 1,260

FM

Poor

Over: WOLF CREEK

0884408, Woodbury, IA

Built 1956 Load: 25.3 t ADT: 40

FM

Poor

Over: ROCK CREEK

081033503, Cedar, IA

Built 1959 Load: 25.4 t ADT: 1,350

275TH

Poor

Over: WILLOW CREEK

096210603, Cerro Gordo, IA

Built 1941 Load: 25.4 t ADT: 91

YARD G ROAD

Poor

Over: LONG CREEK

APPROX. 4000' S. OF RD. I, Des Moines, IA

Built 1910 Load: 25.4 t ADT: 10

LOCAL ROAD

Poor

Over: MIDDLE FORK OF BEAVER CR

089182802, Grundy, IA

Built 1976 Load: 25.4 t ADT: 20

LOCAL

Poor

Over: STREAM

078140301, Poweshiek, IA

Built 1964 Load: 25.4 t ADT: 11

LOCAL

Poor

Over: N FORK LONG CR

075070103, Washington, IA

Built 1973 Load: 25.4 t ADT: 60

LOCAL ROAD

Poor

Over: WHISKEY CREEK

076063202, Washington, IA

Built 1969 Load: 25.4 t ADT: 71

FM

Poor

Over: BRUSHY FORK CREEK

083350804, Carroll, IA

Built 1964 Load: 25.5 t ADT: 650

LOCAL ROAD

Poor

Over: BLACK HAWK CREEK

087151403, Grundy, IA

Built 1979 Load: 25.5 t ADT: 20

LOCAL

Poor

Over: BR BEAVER CREEK

089171401, Grundy, IA

Built 1978 Load: 25.5 t ADT: 44

LOCAL

Poor

Over: S. RACCOON RIVER

079311706, Guthrie, IA

Built 1959 Load: 25.5 t ADT: 20

FM 2030 VAIL

Poor

Over: GOLLS CREEK

095231002, Hancock, IA

Built 1969 Load: 25.5 t ADT: 259

LOCAL

Poor

Over: DD #13

090332504, Pocahontas, IA

Built 1971 Load: 25.5 t ADT: 60

LOCAL

Poor

Over: RUTT BRANCH

075331202, Adair, IA

Built 1960 Load: 25.6 t ADT: 62

LOCAL

Poor

Over: N CHEQUEST LAKE CR

069120206, Davis, IA

Built 1958 Load: 25.6 t ADT: 161

LOC 333 AVE

Poor

Over: STREAM

087032404, Delaware, IA

Built 1975 Load: 25.6 t ADT: 29

FM

Poor

Over: CREEK

088223202, Hardin, IA

Built 1970 Load: 25.6 t ADT: 177

LOCAL

Poor

Over: WEST FORK BATTLE CREEK

088412603, Ida, IA

Built 1963 Load: 25.6 t ADT: 5

LOCAL

Poor

Over: SMALL CREEK

078143501, Poweshiek, IA

Built 1985 Load: 25.6 t ADT: 50

LOCAL

Poor

Over: LITTLE LICK CREEK

070092903, Van Buren, IA

Built 1972 Load: 25.6 t ADT: 47

LOCAL

Poor

Over: VILLAGE CR

071150104, Wapello, IA

Built 1973 Load: 25.6 t ADT: 70

FM - 690TH

Poor

Over: WATERWAY

076350304, Cass, IA

Built 1963 Load: 25.7 t ADT: 450

SPICER AVE

Poor

Over: STREAM

080010702, Cedar, IA

Built 1915 Load: 25.7 t ADT: 20

APPLE RD.

Poor

Over: SMALL CREEK

095073503, Fayette, IA

Built 1968 Load: 25.7 t ADT: 403

Showing 18,601-18,650 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.