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

SPICER AVE

Fair

Over: SMALL

080011802, Cedar, IA

Built 1999 Load: 23.2 t ADT: 20

THRUSH

Fair

Over: WINNEBAGO RIVER

096192006, Cerro Gordo, IA

Built 1962 Load: 23.2 t ADT: 2,082

I-35

Fair

Over: DRAINAGE DITCH

1.6 MI. N OF Jct. SR C13, Cerro Gordo, IA

Built 1971 Load: 23.2 t ADT: 17,300

FM-530TH ST.

Fair

Over: ROCK CREEK

092413501, Cherokee, IA

Built 1968 Load: 23.2 t ADT: 938

LOCAL

Fair

Over: TRINKLE CREEK

085371802, Crawford, IA

Built 1968 Load: 23.2 t ADT: 21

100 CRANE AVE

Fair

Over: DRAINAGE DITCH 61

094263302, Hancock, IA

Built 1975 Load: 23.2 t ADT: 15

1840 280TH ST

Fair

Over: EAST BRANCH IA RIVER

096240101, Hancock, IA

Built 1976 Load: 23.2 t ADT: 21

FM

Fair

Over: SMALL

088193602, Hardin, IA

Built 1983 Load: 23.2 t ADT: 34

LOCAL 110TH ST

Fair

Over: BR CRANE CREEK

099133301, Howard, IA

Built 1987 Load: 23.2 t ADT: 16

IA 78

Fair

Over: RICHLAND CREEK

5.6 mi. E of jct. IA 149, Keokuk, IA

Built 1938 Load: 23.2 t ADT: 1,190

OLD IA 289

Fair

Over: OVER BNSF RR

067051014, Lee, IA

Built 1958 Load: 23.2 t ADT: 70

US 169

Fair

Over: DRAINAGE DITCH

0.6 MI. N OF Jct. SR G-68, Madison, IA

Built 1976 Load: 23.2 t ADT: 1,890

LOCAL

Fair

Over: STREAM

074181903, Marion, IA

Built 1900 Load: 23.2 t ADT: 10

LOCAL

Fair

Over: OUTLET OF RUSH LAKE

094342104, Palo Alto, IA

Built 1998 Load: 23.2 t ADT: 30

FM

Fair

Over: GRAND RIVER

073292407, Union, IA

Built 1988 Load: 23.2 t ADT: 60

FM

Fair

Over: WILLIAMS CREEK

074073602, Washington, IA

Built 1980 Load: 23.2 t ADT: 380

FM

Fair

Over: NORTH LIZARD CREEK

090303003, Webster, IA

Built 1960 Load: 23.2 t ADT: 489

LOCAL

Fair

Over: BRANCH PAINT CREEK

097041703, Allamakee, IA

Built 1996 Load: 23.3 t ADT: 70

FM

Fair

Over: VILLAGE CREEK

098031814, Allamakee, IA

Built 1958 Load: 23.3 t ADT: 462

475TH ST

Fair

Over: STREAM

069170807, Appanoose, IA

Built 2002 Load: 23.3 t ADT: 11

FM

Fair

Over: ELK RUN CREEK

085341001, Carroll, IA

Built 1956 Load: 23.3 t ADT: 100

LOCAL

Fair

Over: STORM CREEK

085360101, Carroll, IA

Built 1993 Load: 23.3 t ADT: 30

FM - 570TH

Fair

Over: IAIS RR

076370304, Cass, IA

Built 1952 Load: 23.3 t ADT: 79

VINE

Fair

Over: BEAVER CREEK

095192202, Cerro Gordo, IA

Built 1961 Load: 23.3 t ADT: 187

BELGIAM RD

Fair

Over: STREAM

091060204, Clayton, IA

Built 1930 Load: 23.3 t ADT: 30

LOCAL

Fair

Over: JOHNS CREEK

088023504, Dubuque, IA

Built 1979 Load: 23.3 t ADT: 20

LOCAL

Fair

Over: LITTLE MAQUOKETA RIVER

089E20604, Dubuque, IA

Built 1984 Load: 23.3 t ADT: 274

US 30

Fair

Over: ALLEN CREEK

0.9 MI. W OF JCT.29, Harrison, IA

Built 1966 Load: 23.3 t ADT: 6,500

NB I-29

Fair

Over: BURCHAM CREEK

2.7 MI. S OF JCT 127, Harrison, IA

Built 1967 Load: 23.3 t ADT: 7,600

LOCAL

Fair

Over: BR BATTLE CREEK

088412701, Ida, IA

Built 1969 Load: 23.3 t ADT: 21

FM

Fair

Over: N FORK MAQUOKETA RIVER

085E10506, Jackson, IA

Built 1961 Load: 23.3 t ADT: 60

JUNGLETOWN RD.

Fair

Over: SMALL CREEK

083021503, Jones, IA

Built 1998 Load: 23.3 t ADT: 62

45TH AVE.

Fair

Over: BEERS CREEK

084010908, Jones, IA

Built 1978 Load: 23.3 t ADT: 51

170TH AVE.

Fair

Over: BEAR CREEK

084030402, Jones, IA

Built 1976 Load: 23.3 t ADT: 51

120TH ST

Fair

Over: BIG BEAR CREEK

084030901, Jones, IA

Built 1991 Load: 23.3 t ADT: 21

130TH AVE.

Fair

Over: BRANCH OF KITTY CREEK

085020702, Jones, IA

Built 1975 Load: 23.3 t ADT: 104

190TH AVE

Fair

Over: KITTY CREEK

085031802, Jones, IA

Built 1991 Load: 23.3 t ADT: 104

STONE BRIDGE RD

Fair

Over: DRY CREEK

086031704, Jones, IA

Built 1997 Load: 23.3 t ADT: 294

120TH AVE

Fair

Over: BRANCH KITTY CREEK

085021704, Jones, IA

Built 1981 Load: 23.3 t ADT: 29

FM

Fair

Over: STREAM

076111002, Keokuk, IA

Built 1948 Load: 23.3 t ADT: 20

WILSON DR

Fair

Over: STREAM

074183403, Marion, IA

Built 2012 Load: 23.3 t ADT: 51

FM

Fair

Over: OVER BNSF RR

076203304, Marion, IA

Built 1966 Load: 23.3 t ADT: 190

KIRKWOOD AVE

Fair

Over: ROCK CREEK

097171404, Mitchell, IA

Built 1955 Load: 23.3 t ADT: 39

LOCAL

Fair

Over: MUD CREEK

094410502, O'Brien, IA

Built 1950 Load: 23.3 t ADT: 72

CO PARK RD

Fair

Over: STREAM

095342803, Palo Alto, IA

Built 1916 Load: 23.3 t ADT: 35

FM

Fair

Over: DD

096323602, Palo Alto, IA

Built 1978 Load: 23.3 t ADT: 40

LOCAL

Fair

Over: SMALL STREAM

078391203, Shelby, IA

Built 1988 Load: 23.3 t ADT: 11

FM

Fair

Over: BRANCH SOUTH RIVER

075250102, Warren, IA

Built 1940 Load: 23.3 t ADT: 29

LOCAL

Fair

Over: STREAM

087452602, Woodbury, IA

Built 2001 Load: 23.3 t ADT: 11

RIVER RD

Fair

Over: BLACK HAWK CREEK

CITY BRIDGE NO. 29, Black Hawk, IA

Built 1971 Load: 23.4 t ADT: 6,513

Showing 3,651-3,700 of 20,753 bridges

Related

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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.